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576 Cards in this Set
- Front
- Back
tight junction
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no intercellular space
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gap junctions
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link together cytoplasm of adjacent cells. consist of protein channels that allow ions to flow through freely.
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desmosomes
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plaque-like proteins embedded in the cell membrane to which the cytoskeleton is attached. responsible for structural integrity of tissue. hold cells tightly together.
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peroxisomes contain...
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catalase, an enzyme relevant to the processing of hydrogen peroxide.
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inner mitochondrial membrane is folded into convolutions called...
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cristae
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interior of the inner mitochondrial membrane is termed the...
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matrix
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plastids
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contain pigment and function in photosynthesis
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cilia and flagella are composed of...
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microtubules
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centrioles are composed of...
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microtubules
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the cytoplasm is composed of...(2 things)
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microtubules and microfilaments
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microtubules are composed of...
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tubulin
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microfilaments are composed of...
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actin
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commensalism
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a relationship in which one organism benefits but the other is neutral
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mutualism
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a relationship in which both organisms benefit
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hemizygous
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having only one copy of a gene rather than the normal two copies. sex chromosomes.
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homologous
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the 22 pairs of non-sex chromosomes. Have 2 copies of the chromosome. autosomes.
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nucleosomes
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the visible units of the histone
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nucleic acids (DNA, RNA) are bound in a strand by what kind of bond?
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phosphodiester bonds
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antiparallel orientation
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one strand runs from 5' to 3', while the opposite runs from 3' to 5'.
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DNA replication begins at the...
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origin of replication
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origin of replication
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a specific sequence of nucleotides that are the signal to start DNA synthesis
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helicase
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unwinds the DNA strands
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replication bubble w/ 2 replication forks
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the part of the DNA where the strands have been separated by helicase. The daughter strands begin to form in it.
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DNA polymerases
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synthesize the new strand of DNA. Read template in 3' to 5' direction and synthesize DNA in the 5' to 3' direction.
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primase
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lays down short RNA primers so DNA polymerase can begin.
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semiconservative
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describes DNA replication, b/c each of the newly formed molecules contains half of the original DNA molecule.
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semidiscontinuous synthesis
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the production of a nucleotide chain via Okazaki fragments.
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joins Okazaki fragments
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DNA ligase
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template / non-coding / anti-sense strand
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the DNA strand that serves as a template and is actually read and transcribed in mRNA synthesis
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RNA polymerases
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function in transcription
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sigma factor
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binds RNA polymerase to the DNA template
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promoter
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where RNA polymerase binds DNA. determines which DNA strand is the template, where transcription starts, and the direction of transcription.
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start site
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where transcription begins. the last position of the promoter site.
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Pribnow box
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common to all promoters. the sequence TATAAT at or near the -10 position.
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consensus sequences
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common to all promoters. Refers to the Pribnow bow and to the TTGACA sequence at the -35 position
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transcription unit
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the length of the molecule from promoter site to terminator. Includes the promoter site, the sequences that are transcribed, and the terminator.
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the four steps of transcription:
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1) template recognition
2) initiation 3) elongation 4) termination |
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the nucleotides that begin at the template are...
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ribonucleoside triphosphates (NTPs)
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the creation of a phosphodiester bond causes the release of...
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pyrophosphate (PPi)
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initiation is complete when...
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the sigma factor detaches from the RNA polymerase
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process of initiation (5 steps):
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1) 2 nucleotides approach DNA template
2) temporary hydrogen bonds form --> DNA-RNA hybrid 3) RNA polymerase catalyzes formation of phosphodiester bond 4) NTPs added 5) sigma factor detaches from RNA polymerase ---> initiation complete |
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process of transcription (4 steps):
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1) binding of RNA polymerase to promoter on DNA
2) unwinding of DNA 3) positioning of 2 nucleotides 4) formation of phosphodiester bonds |
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the region of unwinding of DNA is called the...
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transcription bubble
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hairpin loop
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created by a large number of G-C sequences followed by several U residues (GCGC...UUU).
the GC sequence folds in on itself to create a loop. this causes the RNA polymer to slow or pause. the remaining AU sequence breaks apart easily, terminating RNA synthesis |
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rho factor
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causes the RNA-DNA hybrid to unwind, terminating RNA synthesis.
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RNA polymerase I
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synthesizes rRNA in eukaryotic cells
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RNA polymerase II
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synthesizes mRNA in eukaryotic cells
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RNA polymerase III
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synthesizes tRNA in eukaryotic cells
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control sequences
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modulate the efficacy of eukaryotic promoters
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the consensus sequence in eukaryotic cells
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the TATA box, located 30 base pairs upstream of the start site
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4 differences btwn transcription in bacteria and in eukaryotic cells
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1) site of transcription
2) types of RNA polymerase 3) nature and complexity of promoters 4) presence of transcription factors 5) processing (spicing, 5' cap, poly A tail) |
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transcription factors
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proteins that bind w/ the DNA promoter site and interact w/ one another to facilitate the binding of the polymerase to the promoter. only in eukaryotic cells.
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primary transcriptase / hnRNA
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an mRNA molecule freshly produced by transcription in eukaryotes. not functional; a precursor to a functional RNA molecule.
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three steps of RNA processing
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splicing, 5' end modification, 3' end modification
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5' end modification --> 5' cap
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5' end binds to guanine by 5' - 5' linkage.
guanine unit undergoes methylation, methylated guanine residue becomes molecule's 5' cap. |
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poly A tail
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a long run of adenine residues added at the 3' end of the mRNA
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5 steps of translation
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1) ribosome recognizes mRNA and binds
2) ribosome reads mRNA, three nucleotides at a time 3) each codon orders a particular amino acid to be brought to the ribosome 4) tRNA w/in cytosol bring amino acids to ribosome 5) amino acids form peptide bonds to form polypeptide |
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codon
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3 nucleotides
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two subunits of a prokaryotic ribosome
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one large (50S) and one small (30S)
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three binding sites of tRNA
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A site, P site, E site
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polyribosome
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in both prokaryotes and eukaryotes, many ribosomes synthesizing the same protein simultaneously associate w/ one another
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two functional sites of tRNA
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anticodon and amino acid acceptor site
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anticodon
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sequence of three nucleotides. where mRNA binds to the tRNA.
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amino acid acceptor site
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where tRNA binds to an amino acid.
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aminoacyl-tRNA synthetase
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recognizes the tRNA carrier and the amino acid to which it is specific.
Recognition btwn tRNA and amino acid, therefore, is mediated not by tRNA, but by the relevant aminoacyl-tRNA synthetase. |
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aminoacyl-tRNA
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produced when a tRNA and an amino acid are bound together
tRNA^(name) when unbound, (name)-tRNA^(name) when bound to amino acid |
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amino acid activation
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the binding of an amino acid to its tRNA to produce the corresponding aminoacyl-tRNA
an endergonic reaction (delta G is positive) involving the cleavage of two high-energy phosphate bonds amino acid + ATP + tRNA --> aminoacyl-tRNA + AMP + PPi |
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3 phases of translation:
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1) initiation
2) elongation 3) termination |
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translation involves reading the mRNA transcript from...
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5' to 3'
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5' untranslated region (5' UTR)
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contains upstream regulatory sequences that are essential for initiation
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3' untranslated region (3' UTR)
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contains downstream regulatory sequences that help w/ termination
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start codon
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the first AUG codon on the mRNA
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initiation complex
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the small ribosomal subunit (30S), fMet-tRNA^(Met), and molecule of mRNA
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3 steps of initiation of translation:
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1) 30S subunit binds to 5' end of the mRNA transcript
2) UAC anticodon of fMET-tRNA^(Met) binds AUG start codon on mRNA 3) large ribosomal subunit joins initiation complex to form 70S ribosome |
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4 steps of elongation of translation:
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1) mRNA codon exposed at A site of codon
2) aminoacyl-tRNA arrives at A site and forms hydrogen bonds w/ codon. Step requires hydrolysis of GTP. 3)peptidyl transferase transfers amino acid in P site from tRNA carrier to amino terminus of aminoacyl-tRNA in the A-site. Peptide bond formed. 4) Ribosome translocates 3 nucleotides along mRNA in 5' to 3' direction. This moves polypeptide to P site, old tRNA to E site, and exposes next mRNA to A site. Requires hydrolysis of one GTP. |
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E site
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always contains a tRNA that has lost its amino acid to the growing peptide chain.
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P site
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always contains a tRNA hydrogen bonded to the mRNA transcript, and this anchors the peptide chain to the ribosome.
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A site
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always where the next aminoacyl-tRNA arrives
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it costs _____ phosphate bonds to add an amino acid to fMet
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4. 2 bonds to join tRNA w/ amino acid, 1 to bring aminoacyl-tRNA into A site, 1 to translocate the ribosome so the next codon can be read.
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stop codons
|
UAG, UGA, UAA (U Are Gone, U Go Away, U Are Away).
Do not code for tRNA molecules. Their arrival at A site causes release factors (proteins) to stop elongation and to release polypeptide. |
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release factors
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stop the elongation process
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codon
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a series of three mRNA nucleotide units recognized by complementary tRNA nucleotide units
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prokaryotic ribosomal subunits
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30S and 50S. 70S ribosome.
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eukaryotic ribosomal subunits
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40S and 60S. 80S ribosome.
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nucleolus
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where rRNA and ribosomes are synthesized
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Shine-Dalgarno sequence
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A common 5' UTR (untranslated region) in prokaryotes.
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Kozak sequence
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a common 5' UTR in eukaryotes
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5' UTR
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functions in assembly of the translation initiation complex
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first amino acid in prokaryotes
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fMet-tRNA
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first amino acid in eukaryotes
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methionine (Met-tRNA, not fMet-tRNA)
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differences in timing of transcription and translation in eukaryotes vs. prokaryotes
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transcription and translation occur simultaneously in prokaryotes, but not in eukaryotes b/c they occur in different places
eukaryotes must undergo mRNA processing |
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genetic code
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the association btwn each mRNA codon and the amino acid for which it codes
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degenerate
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the genetic code does not represent a 1-to-1 codon-amino acid ratio; any given amino acid might be coded for by more than one mRNA codon
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transcription unit
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the portion of a DNA molecule that undergoes transcription, from promoter site to terminator
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diploidy
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the state in which every chromosome of a cell has a homologue. 2N.
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haploid
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the state in which chromosomes lack a homologous counterpart. 1N.
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centromere
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where each pair of duplicate chromosomes is joined.
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sister chromatid
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each member of the chromosome pair
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aster fibers
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star-shaped fibers that form around the centrioles.
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prometaphase (early metaphase) is marked by...
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complete dissolution of the nuclear membrane
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kinetochore
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the protein structure on chromosomes where the spindle fibers attach during cell division to pull the chromosomes apart.
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metaphase
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chromosomes align on the metaphase plate so that centromeres line in a plane at the cell's midpoint.
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anaphase
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sister chromatids separate and move toward opposite poles of the cell.
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daughter chromosome
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separated sister chromatids
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telophase
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daughter chromosomes are positioned at opposite poles of the cell, and the kinetochore fibers disappear.
Nuclear membrane forms around each set of daughter chromosomes. chromosomes condense. nucleoli reappear. |
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prophase
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chromosomes condense. nucleolus disappears. centrioles move to opposite poles of the cell. aster fibers form around centrioles. mitotic spindle forms and nuclear membrane dissolves.
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cytokinesis
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begins during end of anaphase or beginning of telophase.
cleavage furrow forms at center of cell, dividing cell. |
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reduction division
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the generation of haploid daughter cells by a diploid parent cell. accomplished by meiosis.
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tetrads
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homologous pairs of duplicated chromosomes align in proximity to one another. occurs in prophase I of meiosis.
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synapsis
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the association of homologous pairs of duplicated chromosomes to form a tetrad
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chiasma / synaptonemal membrane
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the site at which crossing over occurs
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meiotic metaphase I
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PAIRS of homologous chromosomes align on the spindle apparatus
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meiotic anaphase I
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homologous chromosome pairs separate and move to opposite poles of the cell. Centromeres DO NOT split.
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spermatogenesis occurs in the ______
|
seminiferous tubules
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zygote
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diploid cell resulting from the fusion of a sperm and ovum
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spermatogonia
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relatively undifferentiated cells w/in the seminiferous tubules of the testes
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primary spermatocyte
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b/f first meiotic division
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secondary spermatocyte
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after first meiotic division, b/f second meiotic division.
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spermatids
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haploid. Result from second meiotic division of secondary spermatocytes
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epididymis
|
a coiled tube that serves as the site of maturation and storage for sperm
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acrosome
|
part of sperm filled w/ degradative enzymes that facilitate penetration of the ovum during fertilization
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order of structures through which sperm travel
|
seminiferous tubule, epididymis, vas deferens, ejaculatory duct, urethra
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ootid
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haploid. an immature ovum.
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oogonium
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the diploid precursor to the ovum.
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follicle
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the ovum and supporting cells
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ovulation
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a follicle ruptures, releasing the ovum, which then enters the fallopian tubes
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fallopian tube
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connects the ovaries and the uterus. normally the site of fertilization.
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outer membrane of the ovum
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corona radiata
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inner membrane of the ovum
|
zona pellucida
|
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fertilization
|
sperm releases enzymes from its acrosome, which degrade the corona radiata and zona pellucida
fertilization is complete when sperm and ovum nuclei have fused to form the zygote |
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endometrial tissue
|
the lining of the uterus. the site of implantation.
|
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placenta
|
develops at the site of implantation.
the site of the transfer of nutrients from the mother to fetus as well as waste products from fetus to mother. |
|
order the developmental stages the embryo passes through
|
zygote, cleavage, morulation, blastulation, gastrulation, germ layer formation, neurulation
|
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cleavage
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a series of rapid cell divisions
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morula
|
when the developing organism consists of ~32 cells
|
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blastula
|
a hollow ball of cells
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blastocoel
|
the fluid-filled center of the blastula
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gastrulation
|
invagination of the blastula to form a gastrula
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________ marks the beginning of morphogenesis
|
invagination
|
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neurulation
|
a portion of the mesoderm forms a tubelike structure called the notocord.
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neural plate
|
forms above the notocord from thickened ectoderm
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neural tube
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formed from invagination of the neural plate. a precursor to the brain, spinal cord, and components of the eye.
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morphogenesis
|
"genesis of form". part of gastrulation
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induction
|
development of one region of tissue is influenced by the tissues that surround it.
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differentiation
|
the process by which a cell becomes more specialized
|
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determination
|
the process whereby the number of possible tissue types a cell could become is progressively limited
|
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endoderm gives rise to...
|
inner lining of esophagus, stomach, and intestines.
also organs that are outgrowths of the digestive system, such as pancreas, gall bladder, and liver. also inner lining of the respiratory tract. |
|
ectoderm gives rise to...
|
epidermis, eye, and nervous system
|
|
mesoderm gives rise to...
|
connective tissue, heart, blood cells, and urogenital system.
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bacilli
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rod-shaped bacteria
|
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cocci
|
round-shaped bacteria
|
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spirilla
|
spiral-shaped bacteria
|
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binary fission
|
the asexual reproduction of a bacterium
|
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transformation
|
involves the addition and incorporation of genetic material into a bacterium's genome from its surroundings.
|
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conjugation
|
a plasmid transfers DNA from one bacterium to another. bacterial "mating"
|
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F (fertility) factor
|
a bacterial plasmid which facilitates the transfer of DNA from one bacterium to another.
|
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transduction
|
a virus transfers DNA from one bacterium to another.
|
|
the proteinaceous outer coat of a virus
|
capsid
|
|
the nucleic acids contained w/in the coat
|
core
|
|
bacteriophage
|
a type of virus that infects bacteria using a tail fiber
|
|
tail fiber
|
used by bacteriophages to facilitate infection by allowing the virus to attach itself to the bacterial host, and to inject its genome into the host.
|
|
receptors
|
found on the host's cell membrane. facilitate the attachment of viral protein coat molecules.
|
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lytic virus
|
appropriates the cell's reproductive machinery to make copies of its own nucleic acids and proteins, which then combine to form new viruses.
|
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lysogenic virus
|
incorporates its nucleic acid into the host's genome
|
|
prophage
|
a lysogenic virus that infects bacteria
|
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provirus
|
a lysogenic virus that infects eukaryotic cells
|
|
fungi
|
primarily haploid organisms whose cells are eukaryotic
|
|
fungal cell walls are composed largely of __________
|
chitin
|
|
unicellular fungi
|
yeasts
|
|
multicellular fungi
|
molds, mushrooms, and mildews
|
|
the principle distinguishing feature of many multicellular fungi
|
the absence of a partition btwn what would otherwise be separate cells. somewhat multinucleate.
|
|
asexual fungal reproduction occurs through... (3 things)
|
budding, fission, or spore formation
|
|
budding
|
a cell separates from the parent organism, grows, and becomes a new organism itself.
|
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fission
|
a single fungal cell divides to produce two new daughter cells.
|
|
sporulation
|
fungus produces spores and release them from hyphae.
allows undeveloped organism to survive hostile environmental conditions |
|
hyphae
|
stem-like structures from which fungi produce and release spores.
produce gametes. |
|
autotrophs
|
capture their own energy through photosynthesis or through chemical means
|
|
heterotrophs
|
rely on other organisms for nutrition
|
|
parasites
|
obtain nutrition directly from the body of a living organism to the detriment of that organism.
|
|
saprophytes
|
absorb nutrients from the remains of dead organisms
|
|
obligate anaerobes
|
unable to live in the presence of oxygen
|
|
faculative anaerobes
|
use oxygen in their respiratory process if it is available, but will conduct anaerobic respiration in its absence.
|
|
tolerant anaerobes
|
always conduct anaerobic respiration but are indifferent to the presence of oxygen.
|
|
mutualism
|
a relationship btwn two organisms in which each confers a benefit on the other.
|
|
active site
|
the site at which an enzyme associates w/ its substrate.
|
|
lock-and-key hypothesis
|
states that an enzyme's shape accommodates precisely the shape of the substrate.
|
|
induced fit hypothesis
|
states that the enzyme's shape compels the substrate to take on the shape of the reaction's transition state.
|
|
denaturation
|
the breakdown of an enzyme's shape.
occurs under conditions that disrupt the hydrogen bonds functioning to maintain secondary and tertiary structure. |
|
cofactors
|
inorganic substances (ex. Fe and Cu ions) that certain enzymes require for their activity
|
|
coenzymes
|
organic substances, such as vitamins, that certain enzymes require for their activity
|
|
competitive inhibition
|
substrate and inhibitor compete for an enzyme's active site
|
|
glycolysis produces net gain of...
|
2 ATP, 2 NADH
|
|
fermentation
|
the anaerobic process in which pyruvate is reduced by NADH to produce lactate, regenerating NAD+
|
|
fermentation produces net gain of...
|
2 NAD+, 2 lactate
|
|
oxidative decarboxylation
|
occurs after glycolysis in preparation of Kreb cycle.
acetyl group that is produced is combined w/ coenzyme A to produce acetyl CoA |
|
Kreb / citric acid cycle
|
pyruvate + CoA + NAD+ --> acetyl CoA + CO2 + NADH
acetyl CoA + oxaloacetate --> citrate citrate undergoes series of redox rxns that lead to removal of 2 carbons as CO2. Energy released is used to produce 3 NADH and 1 FADH2 |
|
products of one turn of Kreb's cycle:
|
3 NADH
1 FADH2 1 GTP 2 CO2 |
|
respiration is controlled by the _______
|
medulla oblongata
|
|
part of the medulla oblongata in which signals that initiate each cycle of breathing arise
|
respiratory center
|
|
the major muscle of respiration
|
diaphragm
|
|
carries signals from the medulla oblongata to the diaphragm, stimulating the diaphragm to contract
|
phrenic nerve
|
|
the _________ of the lung causes it to resist expansion
|
elasticity
|
|
nose and mouth
|
serve to warm and moisten air as it enters the body
|
|
nares
|
nostrils. mucus and hair lining serves to trap large particles in the air
|
|
trachea
|
a mucous-membrane lined tubular structure whose lumen (airway) is kept open by cartilaginous rings embedded in the wall.
|
|
macrophages
|
phagocytize small particles that reach the alveoli
|
|
surfactant
|
relieves surface tension. has a polar and a nonpolar end. keeps alveoli from collapsing.
|
|
the respiratory center is most sensitive to:
|
carbon dioxide concentration
|
|
myocardium
|
the muscular tissue of the heart
|
|
leaflets / cusps
|
make up heart valves. Open when pressure is applied in the forward direction and close when pressure is applied in the backward direction.
|
|
native position
|
closed (heart valve)
|
|
tricuspid valves
|
tricuspid, pulmonic, and aortic valves
|
|
diastole
|
the atria are first relaxed and then contracted.
|
|
systole
|
the two ventricles contract
|
|
vagus nerve
|
slows the rate of the sinus node to decrease heart rate
|
|
purkinje fibers
|
spreads the electrical signal throughout the ventricular walls
|
|
platelets
|
cell fragments of a megakaryocyte that function in clotting
|
|
all blood cells arise from precursor cells w/in the ___________
|
bone marrow
|
|
hematocrit
|
the percentage of whole blood volume occupied by red cells
|
|
plasma
|
blood stripped of its cells
|
|
serum
|
plasma w/out fibrin
|
|
oncotic pressure
|
a specific form of osmotic pressure across capillary walls due to the presence of proteins in the blood.
functions to push fluids into the capillary. |
|
hydrostatic pressure
|
pushes fluid out of the capillary
|
|
lymph enters ultimately into the __________ ...
|
thoracic duct, which enters ultimately into the venous system at the junction of the left internal jugular and subclavian veins
|
|
spleen
|
acts as a lymphatic filter for blood.
destroys senescent (aged) erythrocytes |
|
thymus
|
the place of maturation of T-lymphocytes. becomes nonfuctional in adulthood.
|
|
T-cells
|
cell-mediated immunity
|
|
digestive enzyme in saliva that initiates the digestion of starch:
|
salivary amylase
|
|
peristalsis
|
a highly coordinated series of contractions which allow for transit of a bolus
|
|
parietal cells
|
secrete hydrochloric acid into the stomach
|
|
stimulates the production and secretion of HCl:
|
vagus nerve
|
|
chief cells
|
secrete pepsin into the stomach
|
|
pepsin
|
initiates the chemical breakdown of proteins. requires low pH.
|
|
pyloric sphincter
|
separates stomach from the large intestine.
|
|
duodenum
|
the first section of the small intestine
|
|
chyme
|
liquid food mixture once it is in the intestine
|
|
pancreas
|
synthesizes enzymes that are delivered into the duodenum via the pancreatic duct
|
|
zymogens
|
an inactive form of pancreatic enzymes. cleaved by an enzyme to be activated.
|
|
trypsin
|
an active protein-degrading enzyme
|
|
pancreatic amylase
|
chemically identical to salivary amylase. continues the digestion of carbohydrates.
|
|
bile
|
produced in the liver and stored in the gall bladder.
acts as an emulsifier. |
|
emulsifier
|
separates large globules of fat molecules into smaller globules
|
|
bile enters the duodenum from the gall bladder via the ...
|
common bile duct
|
|
glycogen
|
the storage form of glucose
|
|
functions of the liver
|
1) bile production
2) carbohydrate metabolism (converting glucose to glycogen) 3) converting amino acids into keto acids and urea 4) processing toxins 5) degradation of aged erythrocytes |
|
ileocecal valve
|
separates the small and large intestines
|
|
the most important function of the large intestine is ...
|
the resorption of large amounts of water
|
|
inorganic constituents of bone matrix
|
calcium and phosphate
|
|
a crystalline compound formed from calcium and phosphorous in the bone
|
hydroxyapatite
|
|
organic components of bone matrix
|
Type I collagen and ground substance
|
|
ground substance consists largely of... (2 things)
|
glycosaminoglycans and proteins
|
|
______ and _______ create the characteristic hardness and resistance of bone
|
hydroxyapatite and collagen
|
|
osteoblasts
|
located on inner surfaces of bone tissue. synthesize Type I collagen and other organic components of the matrix.
|
|
osteocytes
|
occupy lacunae w/in the bony matrix. osteoblasts w/ greatly reduced synthetic capacity. responsible for maintaining the matrix.
|
|
lacunae
|
minute spaces w/in the bony matrix
|
|
osteoclasts / multinucleated giant cell
|
promote ongoing breakdown, resorption, and remodeling of bone
|
|
collagen
|
imparts flexibility to bone
|
|
compact bone
|
the outer, dense portion of bone
|
|
spongy bone
|
the inner spongy-looking area of bone w/ small, marrow-filled cavities.
|
|
red bone marrow
|
the site of red blood cell and platelet production and some immune cell development and maturation.
confined to flat bones in healthy adults. |
|
yellow bone marrow
|
filled w/ adipocytes (fat cells)
|
|
lamellae
|
rings running parallel to the bone's long axis that make up a Haversian system, or osteon
|
|
Haversian system / osteon
|
distribute nutrients throughout compact bone. give compact bone its strengh.
each is a set of concentric lamellae |
|
Haversian canal
|
at the center of each Haversian system.
carries blood vessels and nerves, and is filled w/ loose connective tissue. |
|
spicules
|
thin segments of bone in spongy bone that surround the many small marrow spaces.
absorb nutrients directly from the marrow, so do not need Haversian systems. |
|
fibrous joints
|
composed of collagen fibers and are designed to allow minimal movement
|
|
synovial joints
|
allow for a great range and extent of movement
|
|
synovial capsule
|
made of fibrous tissue covering the ends of two bones. contains synovial fluid
|
|
articular cartilage
|
covers the ends of bones in a synovial joint.
|
|
ligaments
|
attach bone to bone
|
|
tendons
|
attach muscles to bones
|
|
myofibers
|
skeletal muscle cells
|
|
fascicle
|
a group or bundle of myofibers
|
|
sarcomere
|
a segment of muscle fiber btwn two Z lines
|
|
thin filament
|
anchored at one end to a Z line.
composed of actin. |
|
thick filament
|
have no connection to the Z lines.
composed of myosin. |
|
contraction of muscle is achieved by...
|
the sliding of actin and myosin filaments over each other, bringing the Z lines closer together
|
|
A band
|
the length of a myosin (thick) filament
|
|
I band
|
the length of thin filament that does not overlap w/ any thick filament
|
|
H zone
|
the middle of the sarcomere, containing only myosin filaments w/ no overlapping actin filaments
|
|
crossbridges
|
extend from the myosin filament to the actin filament. allow contraction to occur by a sliding filament mechanism
|
|
ratio moved by Na-K ATPase
|
2 potassium in, 3 sodium out
|
|
relative ion concentrations inside and outside cell
|
Na+ concentration higher outside than inside
K+ concentration higher inside than outside |
|
net relative charge across membrane
|
cell's interior electrically negative relative to its exterior
|
|
membrane resting potential
|
refers to the existence of a charge gradient across the cell membrane and to the fact that the inside is negative to the outside
|
|
depolarized
|
when the charge gradient has reversed itself so that the interior is positive relative to the exterior.
occurs due to the flow of Na into the cell |
|
threshold potential
|
the membrane potential that must be reached for depolarization to occur
|
|
repolarized
|
occurs due to the flow of K into the cell
|
|
action potential
|
designates rapid depolarization followed by repolarization
|
|
tropomyosin
|
covers the site on the actin w/ which myosin heads interact
|
|
troponin
|
binds calcium ions, causing tropomyosin to uncover the actin sites to which myosin attaches
|
|
sarcolemma
|
the cell membrane of a myofiber
|
|
sarcoplasm
|
the cytoplasm of a myofiber
|
|
sarcoplasmic reticulum
|
the endoplasmic reticulum of the myofiber, which stores calcium ions
|
|
acetylcholine
|
a neurotransmitter that is released from a motor neuron when it experiences depolarization
|
|
T-tubules
|
a series of invaginations in the sarcolemma which carry action potentials deep into the myofiber
|
|
phosphocreatinine
|
stored in myofibers. embodies a high-energy phosphate bond. dephosphorylation releases energy, which is used to regenerate ATP from ADP
|
|
cardiac muscle
|
operates involuntarily. structure similar to skeletal muscle's; striated.
have gap junctions. |
|
intercalated disks
|
dark lines which represent gap junctions
|
|
gap junctions
|
attachment points btwn adjacent muscle cells which allow flow of ions from one fiber to the next, so that action potential is easily propagated.
|
|
syncytium
|
a multinucleate mass of cytoplasm resulting from fusion of cells. describes the myocardium.
|
|
smooth muscle
|
under involuntary control.
cells are mononucleate, elongated, and nonstriated. absence of striations due to irregularity of arrangement of actin and myosin filaments. no troponin or tropomyosin, contraction induced differently than in skeletal muscle. have gap junctions |
|
in smooth muscle cells, calcium ions bind to a calcium-binding protein called __________
|
calmodulin
|
|
calcium-calmodulin complex interacts w/ a protein called _________
|
myosin light chain kinase
|
|
myosin light chain kinase
|
directly phosphorylates the myosin head, allowing myosin to form a cross-bridge w/ actin
|
|
kidneys play four important roles in maintaining homeostasis:
|
1) excretion of hydrophilic waste
2) maintain constant solute concentration 3) maintain constant pH 4) maintain constant fluid volume |
|
renal cortex
|
the outer portion of the kidney.
|
|
renal medulla
|
the inner portion of the kidney. composed or renal pyramids.
|
|
renal pyramids
|
wedge-shaped tissue structures composing the renal medulla
|
|
renal pelvis
|
makes up the innermost portion of the kidney, around which the medulla and cortex are wrapped.
an extension and expansion of the ureter. |
|
ureter
|
connects the kidney to the urinary bladder.
|
|
nephron
|
the basic structural and functional unit of the kidney
|
|
renal corpuscle
|
the part of the kidney nephron in which blood plasma is filtered.
comprised of glomerulus, a glomerular basement membrane, and a Bowman's capsule. |
|
renal tubule
|
a hollow tube surrounded by epithelium cells.
|
|
glomerulus
|
a tuft of capillaries in the renal corpuscle
|
|
Bowman's capsule
|
a double-walled cup formed as an enlargement of the proximal end of the renal tubule.
functions in blood filtration |
|
course of renal tubule
|
Bowmans capsule, proximal convoluted tubule, descending loop of Henle, ascending loop of Henle, distal convoluted tubule, collecting duct
|
|
located in the renal cortex are:
|
renal corpuscle, proximal convoluted tubule
|
|
location of the loop of Henle
|
dips into the pyramids of the renal medulla and courses back into the cortex
|
|
location of the collecting duct
|
courses back down into the medullary pyramids
|
|
papillary duct
|
formed from the merging of many nearby collecting ducts.
empty into the calyces of the renal pelvis |
|
calyces
|
funnel-shaped sections of the renal pelvis
|
|
micturition
|
urination
|
|
renal artery
|
delivers the blood to be filtered to the kidney. branches off the abdominal aorta.
|
|
afferent arterioles
|
branch off the renal artery. travel to individual renal corpuscles.
|
|
glomerular capillaries
|
branch off the afferent arterioles. inside the Bowman's capsule.
|
|
visceral layer
|
the inner wall of the Bowman's capsule. porous and permeable to plasma and other small blood constituents.
|
|
parietal layer
|
the exterior wall of the Bowman's capsule. neither porous nor permeable.
|
|
Bowman's space
|
the space enclosed by the parietal and visceral layers. the origin of the renal tubule.
|
|
filtrate
|
composed of components that pass from the glomerulus across the basement membrane, through the porous viceral layer of Bowman's capsule and into Bowman's space.
will eventually become urine. |
|
allows for high blood pressure in the capillaries of the glomerulus (2 things)
|
efferent arterioles are narrower than afferent ones
efferent arterioles can constrict |
|
result of relatively high pressure in the capillaries of the glomerulus
|
fluid travels from the capillaries into the Bowman's capsule
|
|
efferent arterioles
|
where the filtered blood leaves the glomerulus. eventually fuses w/ the renal vein.
|
|
most reabsorption in the kidney occurs at the __________
|
proximal convoluted tubule
|
|
secretion
|
the process by which waste molecules are added to the filtrate
|
|
the salt concentration of the cortical interstitial fluid is ______ relative to that of the medullary interstitial fluid
|
low
|
|
descending loop of Henle is permeable / impermeable to...
|
permeable to water, impermeable to solutes
|
|
ascending loop of Henle is permeable / impermeable to...
|
impermeable to water, permeable to sodium
|
|
vasa recta
|
blood vessels continuous w/ the renal vein which reabsorb water that flows into the interstitium of the renal medulla
|
|
permeability of collecting tubule
|
permeable to water (regulated), impermeable to salt
|
|
regulates collecting tubule's permeability to water
|
antidiuretic hormone (ADH) or vasopressin
|
|
vasopressin
|
regulates the permeability of the collecting tubule to water.
synthesized in the hypothalamus and secreted by the posterior pituitary |
|
ADH
|
antidiuretic hormone.
dehydration causes its release. it increase the collecting duct's permeability to water. stored in the posterior pituitary |
|
endocrine system
|
controls body homeostasis by promoting communication among various tissues and organs through the secretion of hormones
|
|
hormones
|
secreted by endocrine glands
act slowly and for long periods to maintain homeostasis come in contact w/ almost every cell in body, but affects only cells that have receptors that bind them |
|
hormones are released from the endocrine gland into ______
|
the bloodstream
|
|
exocrine gland
|
secrete their products into the external environment via ducts
Ex. salivary glands, mammary glands, pancreatic acinar cells, sweat glands |
|
target cells
|
those cells that have receptors for, and therefore are affected by, a specific hormone
|
|
pancreas
|
both endocrine (secretes from acinar cells into duodenum) and exocrine gland
|
|
hormones that pancreas secretes (3 things)
|
insulin, glucagon, somatostatin
|
|
endocrine secretions of the pancreas come from __________
|
islet cells
|
|
islet cells are located in the ______
|
islets of Langerhans
|
|
insulin
|
secreted by beta cells
regulates glucose transport, storage, and metabolism |
|
glucagon
|
secreted by alpha cells
regulates glucose transport, storage, and metabolism |
|
somatostatin
|
secreted by gama cells.
inhibits digestive processes. |
|
glucose in our body comes from... (2 things)
|
polysaccharides that we eat are chemically broken down and then absorbed by the gastrointestinal tract.
glucose is produced by the live and released into the blood |
|
in the absence of insulin...
|
all body cells except those of the brain and liver are impermeable to glucose.
glucose in the blood remains in the blood. |
|
when insulin secretion is high...
|
circulating glucose is taken up by cells throughout the body, lowering blood glucose levels.
|
|
when the liver takes up glucose, it converts it to _________
|
glycogen
|
|
main functions of insulin in the body (4 things)
|
1) increasing cellular uptake of glucose
2) promoting formation of glycogen from glucose in the liver 3) reducing glucose concentration in the blood 4) increasing protein and triglyceride synthesis |
|
glucagon
|
has effects opposite to those of insulin. increases blood sugar concentration. increases breakdown of lipids
promotes the breakdown of glycogen in the liver (glycogenolysis) also promotes the manufacture of glucose in the liver (gluconeogenesis) does NOT decrease cellular uptake of glucose |
|
glycogenolysis
|
the process by which glycogen is broken down in the liver
|
|
gluconeogenesis
|
the process by which glucose is synthesized in the liver from lactate, amino acids, and triglycerides.
|
|
hyperglycemia
|
excessively high levels of glucose in the blood. typically due to diminished insulin secretion or activity.
|
|
hypoglycemia
|
excessively low levels of glucose in the blood. results from elevated levels of insulin or insufficient glucagon levels.
|
|
adrenal gland is composed of... (2 things)
|
adrenal cortex and adrenal medulla
|
|
adrenal cortex
|
the outer portion of the adrenal gland. produces a class of endocrine hormones called corticosteroids
|
|
subdivisions of corticosteroids (3 things)
|
mineralocorticoids, glucocorticoids, sex hormones
|
|
mineralocorticoids
|
affect levels of the minerals sodium and potassium in the body
|
|
the main mineralocorticoid secreted by the adrenal cortex is _______
|
aldosterone
|
|
aldosterone
|
acts at the distal convoluted tubule of the kidney to promote sodium-potassium exchange. increases activity of sodium potassium pumps.
tends to promote the movement of water from tubule to interstitium |
|
ultimate effects of aldosterone (3 things)
|
1) increased urinary excretion of potassium
2) increased interstitial sodium concentration 3) increased water concentration |
|
aldosterone secretion is stimulated by... (3 things)
|
high levels of extracellular potassium, low levels of extracellular sodium, and low fluid levels (blood volume)
|
|
glucocorticoids
|
affect plasma glucose concentrations.
increase blood glucose levels, strengthens cardiac muscle contractions, increases water retention, and have anti-inflammatory and anti-allergic activities. |
|
the main glucocorticoid secreted by the adrenal cortex is _________
|
cortisol
|
|
cortisol
|
released as part of long-term stress response and affects most tissues in the body.
increases plasma glucose levels (via increasing gluconeogenesis) and inhibits immune activity. |
|
cortisol release is controlled by... (2 things)
|
the hypothalamus and the anterior pituitary
|
|
the adrenal cortex secretes low levels of the sex steroids, mostly ______
|
the androgens (sex hormones which are dominant in men)
|
|
the adrenal medulla secretes ________, mostly _________
|
catecholamines, mostly epinephrine / adrenaline
|
|
epinephrine
|
an amino acid derivative that acts like a peptide hormone. reserved for stressful situations in which the body prepares for the "fight or flight" response.
increases heart rate, raises blood pressure, and increases alertness. |
|
thyroid
|
a flat gland located in the neck, in front of the larynx.
synthesizes calcitonin and the thyroid hormones |
|
thyroid hormones include... (2 things)
|
thyroxine (T4) or its analog, triiodothyronine (T3)
|
|
the thyroid hormones are synthesized in the _________ from __________
|
in the follicles of the thyroid gland from the amino acid tyrosine
|
|
polarity of thyroid hormones
|
hydrophobic, travel in the plasma bound to plasma proteins.
lipophilic, not hydrophilic |
|
the release of thyroid hormones is controlled by the (2 things)
|
the hypothalamus and the anterior pituitary
|
|
structural difference btwn thyroxine and triiodothyronine
|
thyroxine contains 4 atoms of iodine,
triiodothyronine contains 3 atoms of iodine |
|
effect of thyroid hormones
|
produce a generalized increase in metabolism
stimulate increased oxygen demand, heat production, growth and development |
|
hypothyroidism
|
refers to an inadequate production of thyroid hormone
patients tend to be overweight and slowed down in physical activities |
|
goiter
|
excessive growth (hypertrophy) of the thyroid due to insufficient dietary iodine.
|
|
calcitonin
|
a peptide hormone that reduces blood calcium concentration and inhibits the normal process of bone resorption
|
|
calcitonin is produced in __________
|
the parafollicular cells of the thyroid
|
|
parathyroids
|
four small glands on the posterior aspect of the thyroid gland
secrete parathyroid hormone |
|
parathyroid hormone (PTH)
|
exerts effects opposite to those of calcitonin.
secreted in response to low blood levels of calcium. increases levels of blood calcium. |
|
effects of parathyroid hormone (3 things)
|
1) increases bone resorption and calcium release
2) increases intestinal calcium uptake 3) promotes calcium re-uptake at the kidney |
|
the ovaries are responsible for the synthesis of ______ and ______
|
estrogen and progesterone
|
|
follicular phase
|
the first phase of the ovarian cycle.
anterior pituitary gland secretes two hormones that stimulate the growth of one follicle containing several ova, only one of which fully matures |
|
the two follicular hormones are _______ and _______
|
follicle-stimulating hormone (FSH) and luteinizing hormone (LH)
|
|
the follicular hormones are secreted by the ___________
|
anterior pituitary gland
|
|
the ovarian follicle releases the hormone ______ as it develops
|
estrogen
|
|
what prevents maturation of more than one follicle at a time during the follicular phase?
|
increased ovarian estrogen release
|
|
at the end of the follicular phase...causing...
|
there is a surge in LH secretion from the anterior pituitary, causing the release of the ovum from the follicle, where it is swept into the fallopian tube
|
|
the ovum is swept into the fallopian tube by _______
|
the fimbrae
|
|
ovulation
|
the release of the ovum from the follicle
|
|
luteal phase
|
the final stage of the ovarian cycle. the corpus luteum secretes estrogen and progesterone
|
|
corpus luteum
|
the part of the ruptured follicle that remains in the ovary.
|
|
menses
|
the first phase of the uterine cycle. shedding of the uterine lining.
occurs at the same time as the early follicular phase in the ovary. |
|
proliferative phase
|
estrogen from the ovaries induces the proliferation of the endometrium.
|
|
secretory phase
|
the final phase of the uterine cycle.
progesterone from the corpus luteum promotes the rapid thickening and vascularization of the uterine lining in preparation for the implantation of the fertilized ovum. |
|
if the ovum is fertilized, the developing placenta begins to secrete ___________
|
human chorionic gonadotropin (hCG)
|
|
human chorionic gonadotropin (hCG)
|
prevents the corpus luteum from degenerating, allowing it to continue secreting progesterone --> maintenance of uterine lining.
|
|
the placenta begins to secrete ________ and _______
|
estrogen and progesterone
|
|
seminiferous tubules
|
located in the testes. contain spermatogonia.
|
|
spermatogonia
|
the precursors of spermatozoa formation.
|
|
testosterone is secreted by...
|
the interstitial cells situated among the seminiferous tubules. secreted under the stimulus of pituitary LH (also called ICSH)
|
|
pituitary LH is also called ________ in males
|
interstitial cell stimulating hormone (ICSH)
|
|
functions of testosterone (2 things)
|
promotes spermatogenesis in the testes
promotes the development of secondary sex characteristics |
|
hypothalamus
|
a portion of the diencephalon of the forebrain.
integrates info from cerebral cortex and limbic systems --> releases hormones that control secretions from the pituitary gland. the "control center" of the endocrine system and autonomic nervous system. |
|
anterior pituitary secretes: (6 things)
|
1) thyroid stimulating hormone (TSH)
2) adrenocorticotropic hormone (ACTH) 3) luteinizing hormone (LH) 4) follicle stimulating hormone (FSH) 5) growth hormone (GH) 6) prolactin |
|
tropic hormones (4 things)
|
act as chemical switches, stimulating or inhibiting other endocrine glands
1) thyroid-stimulating hormone (TSH) 2) adrenocorticotropic hormone (ACTH) 3) luteinizing hormone (LH) 4) follicle stimulating hormone (FSH) |
|
adrenocorticotropic hormone (ACTH)
|
stimulates the adrenal cortex to secrete cortisol
|
|
luteinizing hormone (LH) and follicle stimulating hormone (FSH)
|
stimulates the gonads to promote sex hormone secretion and gamete production
|
|
growth hormone (GH) / somatotropin (STH)
|
influences the development of skeletal muscle, bone, and organs in children
|
|
prolactin
|
targets the female breasts, where it stimulates breast development and milk production
|
|
posterior pituitary stores _________ and ___________
|
secretes antidiuretic hormone (ADH) / vasopressin and oxytocin
|
|
ADH and oxytocin are synthesized in _________ and transported __________ to __________
|
made in neural soma in the hypothalamus and transported via vesicles down axons to the posterior pituitary.
|
|
oxytocin
|
released at childbirth, causing the uterus to contract
|
|
mechanisms of hormone release (3 things)
|
1) regulation by instructions from the brain (hypothalamus and pituitary gland)
2) hormones can regulate other hormones 3) hormone levels controlled by feedback regulation |
|
tropic hormones
|
hormones that control the release of other hormones
|
|
tropic hormone cascade of gamete production and secondary sex characteristics
|
GnRH in hypothalamus --> LH and FSH in anterior pituitary--> sex steroids in ovaries/testes --> gamete production and secondary sex characteristics
|
|
tropic hormone cascade of metabolism, growth, and development
|
TRH in hypothalamus --> TSH in anterior pituitary --> T3 and T4 in thyroid --> metabolism, growth, and development
|
|
tropic hormone cascade of inc. blood glucose, inc. protein catabolism, dec. inflammation
|
CRH in hypothalamus --> ACTH in anterior pituitary --> cortisol in adrenal cortex --> increased blood glucose, increased protein catabolism, decreased inflammation
|
|
major divisions of feedback regulation (2 things)
|
1) change in physiological status in response to hormone can feed back to endocrine gland to stop hormone secretion
2) hormones can cause feedback to the higher regulatory organs (hypothalamus and pituitary gland) that are causing their release |
|
synaptic terminals
|
extensions on the distal end of the axon. contain synaptic vesicles, which store neurotransmitters.
|
|
resting potential
|
-70 millivolts. the charge of the neuronal interior relative to the exterior.
|
|
potassium leak channels
|
causes the neuron's membrane to be somewhat permeable to potassium at rest
|
|
threshold
|
-50 mV. the internal charge that must be reached for voltage gated sodium channels to be opened.
|
|
inactivated sodium channel
|
occurs when cell has depolarized to +35 mV. do not allow sodium into cells but are unable to open. channel must be reset to the closed conformation b/f it can open again, which occurs during absolute refractory period.
|
|
repolarization
|
when the cell's interior becomes negative once again due to the influx of potassium
|
|
hyperpolarization
|
when the potential drops to -90 mV due to delay in closure of the voltage-gated potassium channels
|
|
action potential
|
1) depolarization (-70 mV to +35 mV) due to sodium inflow
2) repolarization (+35 mV to -70 mV) due to potassium outflow |
|
absolute refractory period
|
interval during which a second action potential absolutely be initiated. occurs during depolarization and repolarization to -70 mV.
|
|
relative refractory period
|
interval after cell passes -70 mV and is hyperpolarized. cell is susceptible to another action potential but requires a stimulus stronger than the one normally needed. occurs b/c the potential of the cell is below that of a resting cell.
|
|
myelination
|
schwann cells encase axons of the peripheral nervous system by wrapping layers of their plasma membranes around the axons, creating myelin sheaths
|
|
oligodendrocytes
|
have a similar function as Schwann cells in the central nervous system
|
|
nodes of Ranvier
|
unsheathed areas of the axon that are the only sites available for electrical propagation along the axon.
|
|
saltatory conduction
|
depolarization jumps from one node of Ranvier to the next. accelerates transmission of the impulse.
|
|
when the action potential impulse arrives at the end of the axon, it triggers ___________ to open
|
voltage-gated calcium channels
|
|
once voltage-gated calcium channels open,...
|
Ca2+ flows into the cell, binds w/ regulatory protein and causes exocytosis of neurotransmitter-containing synaptic vesicles
|
|
presynaptic neuron
|
the neuron that releases the neurotransmitter
|
|
synaptic cleft
|
the space btwn the presynaptic membrane and the postsynaptic membrane into which neurotransmitters are released
|
|
ligand-gated ion channels
|
what most postsynaptic receptors are, w/ specific neurotransmitters serving as ligands. binding of neurotransmitter induces conformational change in receptors that open ion channels w/in the membrane
|
|
acetylcholine
|
triggers skeletal muscle contraction.
degraded by the enzyme acetylcolinesterase |
|
epinephrine / adrenaline
|
increases heart rate and blood pressure. decreases metabolic activity.
oxidized by monoamine oxidase (MAO) and methylated by catechol-O-methyl transferase (COMT) to inactive metabolites |
|
sensory / afferent neurons
|
receive info from sensory receptors and send it to central nervous system.
|
|
interneurons / associative neurons
|
receive and process information in the CNS. function in relaying signals from neuron to neuron.
|
|
motor / effector / efferent neurons
|
convey signals from the CNS to the target muscle, organ, or gland.
|
|
meninges
|
layers of connective tissue that protect the CNS
|
|
cerebrospinal fluid (CSF)
|
acts as a liquid shock absorber to protect the CNS
|
|
hindbrain becomes... (3 things)
|
the cerebellum, pons, and medulla
|
|
midbrain becomes...
|
structures that govern visual and auditory reflexes and coordinate information on posture and muscle tone.
|
|
forebrain becomes... (2 things)
|
diencephalon and telencephalon
|
|
diencephalon includes...
|
thalamus, hypothalamus, and pituitary gland
|
|
telencephalon includes...
|
cerebrum, lymbic system, and basal nuclei
|
|
cerebrum divided by __________
|
a longitudinal fissure
|
|
two hemispheres of the cerebrum are connected by a thick bundle of axons called the __________
|
corpus collosum
|
|
cerebral cortex
|
made up of grey matter. conducts the highest of intellectual functions. integrates and interprets sensory signals. governs voluntary motor activity.
divided into frontal, parietal, temporal, and occipital lobes |
|
hypothalamus
|
maintains homeostasis through hormonal regulation
|
|
thalamus
|
relays information btwn spinal cord and cerebral cortex
|
|
pons
|
connects the spinal cord and medulla w/ upper regions of the brain
|
|
grey matter
|
composed of unmyelinated neuronal cell bodies
|
|
white matter
|
composed of myelinated axons
|
|
simple reflex arc
|
stretch receptors register stretch of muscle fibers due to tap on tendon. sensory neuron synapses w/ dendrites of a motor neuron, which sends impulse to muscle fiber bundle.
|
|
stretch receptor
|
specialized endings of affector neurons which are wrapped around individual muscles fibers and register tap-induced fiber stretch.
|
|
somatic nervous system
|
governs voluntary activities that we can consciously control.
afferent neurons receive info from sensory receptors for pain, touch, temperature, and proprioception. efferent neurons innervate skeletal muscles by releasing acetylcholine |
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autonomic nervous system
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controls involuntary actions.
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subdivisions of the autonomic nervous system (2 things)
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parasympathetic and sympathetic nervous systems
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preganglionic neuron
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efferent neuron of the autonomic nervous system. has its cell body in the brainstem or the spinal cord. synapses w/ the postganglionic neuron and releases acetylcholine.
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postganglionic neuron
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can release acetylcholine or norepinephrine to control the effector tissue.
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ganglion
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a cluster of nerve cell bodies in the PNS.
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sympathetic nervous system
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prepares body for fight-or-flight response. increases heart rate and blood pressure, and temporarily inhibits vegetative functions.
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parasympathetic nervous system
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"rest and digest". decreases heart rate and increases digestive activity.
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vagus nerve
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part of parasympathetic nervous system. innervates thoracic and abdominal regions. slows down heart rate at SA node.
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rods
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more sensitive to dim light. responsible for night vision.
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cones
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require abundant light. responsible for color and high-acuity vision.
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nocireceptors
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pain receptors.
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2 functions of ear...
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1) maintenance of postural equilibrium
2) reception of sound |
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the inner ear is the location of __________
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the vestibular apparatus
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vestibular apparatus
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interprets positional information required for maintaining equilibrium
consists of membranous labyrinth situated w/in 3 semicircular canals |
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semicircular canals
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oriented perpendicularly to one another in the vestibular apparatus
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movement of the head causes...
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movement of fluid w/in the labyrinths and displacement of crista
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crista
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specialized hair cells located in the ampulla at the base of the semicircular canals
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vestibular nerve
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conveys sensory impulses initiated by movement of crista to centers in the cerebellum, midbrain, and cerebrum
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directional movement and position are interpreted in the.. (3 things)
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cerebellum, midbrain, and cerebrum
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external ear is composed of the ______
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pinna
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pinna
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funnels sound waves into the ear canal
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tympanic membrane
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located in middle ear. vibrates in response to sound waves.
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vibration of the tympanic membrane sets into motion...
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the three auditory bones, the malleus, incus, and stapes
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movement of the stapes is transmitted across the __________ into the ________
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oval window into the inner ear
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transmission across the oval window into the inner ear sets up...
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vibrations of the fluid of the cochlea
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vibrations in the fluid of the cochlea causes...
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bending of auditory hair cells in the organ of Corti
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the 2 branches of the acoustic nerve are formed by...
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the cochlear nerve and the vestibular nerve
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light enters the _______, transverses the _____, passes through the _______, and proceeds through the _____ and _________ until it reaches the light receptors of the _________
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cornea, aqueous humor, pupil, lens and vitreous humor, retina
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one light reaches the retina, electrical signals are transmitted via the _________ to the brain
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optic nerve
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the lens
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a transparent structure that focuses light rays on the retina
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myopia
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nearsightedness. occurs when the lens focuses light from a distant object in front of the retina
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hyperopia
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farsightedness. occurs when light from a nearby object is focused behind the retina.
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the pigment that mediates rod reception is _________
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rhodopsin
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light reception in cones is mediated by ____________
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opsin
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the iris
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the colored part of the eye. contains muscles that dilate and constrict to regulate the amount of light that reaches the retina
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ciliary muscle
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changes the shape of the lens as the eye shifts its focus from distant to nearby objects
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functions of the skin (3 things)
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1) maintains body temperature
2) registers info from the environment 3) provides a barrier against infection |
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three layers of the skin:
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epidermis, dermis, and subcutaneous tissue
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epidermis
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composed of stratified squamous epithelium and has a layered, flat cell structure.
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stratum corneum
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the external layer of the epidermis, composed of many layers of dead cells.
waterproof, and provides resistance to invasion of the body by microorganisms |
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the dead cells of the stratum corneum contain the protein _________
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keratin
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stratum germinativum
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below the stratum corneum. where skin cells replicate through mitosis and where keratin is produced. migrate upward, loosing contact w/ capillaries, and dying to form layers of the corneum
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dermis
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directly underlies the stratum germinativum of the epidermis, and contains the blood vessels, nerve endings, sebaceous glands, and sweat glands.
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subcutaneous tissue / hypodermis contains primarily__________
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adipose tissue (fat)
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in most eukaryotic organisms, most genes code for ___________
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peptides
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introns
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non-protein coding DNA sequences found in eukaryotes
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three gene products:
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rRNA, tRNA, polypeptide
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genetic locus
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the area on a chromosome on which a gene is physically located.
a gene's address on the chromosome and in the genome. |
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at any given genetic locus, the two chromosomes of a given homologous gene pair might be: (2 options)
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a) identical in DNA sequence and code for the same form of the gene
b) different in DNA sequence and code for different versions of the same gene |
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alleles
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different forms or versions of a gene
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homozygous
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having the same allele on both homologous chromosomes
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heterozygous
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having two different alleles
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genotype
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the full complement of alleles possessed by an organism
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law of segregation
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allele pair separate during gamete formation, and randomly unite at fertilization
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law of independent assortment
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allele pairs separate independently during gamete formation
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phenotype
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an organism's traits
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genotype
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an organism's overall inventory of alleles
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homozygous
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two alleles for a given locus, or gene, are identical
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heterozygous
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two alleles on corresponding sites of homologous chromosomes are different
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testcross
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one of the mated individuals is homozygous recessive.
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incomplete dominance
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producing an intermediate phenotype or a blended phenotype
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co-dominance
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two different alleles for the same locus express themselves as two distinct phenotypes both present in a single individual.
Ex. blood groups (possible to have AB) |
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I^A allele
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codes for an enzyme that adds the sugar galactosamine to the lipids on the surface of red blood cells
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I^B allele
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codes for an enzyme that adds the sugar galactose to the lipids on the surface of red blood cells
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genetic recombination
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genetic information on one chromosome is moved to:
1) a chromosome that belongs to some other cell, or 2) a different chromosome w/in the same cell |
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point mutation
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when one nucleotide unit is substituted for another
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frameshift mutation
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occurs when one or more nucleotides are added or deleted
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silent mutation
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does not change the amino acid that is added during translation, and therefore does not affect gene function
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missense mutation
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changes the amino acid that is added, and therefore affects gene function
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nonsense mutation
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if the mutation causes the conversion of an mRNA codon to a stop codon
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autosomes
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the 22 pairs of homologous chromosomes
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autosomal traits
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affect males and females w/ equal frequency
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mitochondrial traits
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passed onto offspring from the mother. either present or absent, recessive/dominant doesn't apply.
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y-linked traits
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passed from father to son, never affect females. either present or absent, recessive/dominant doesn't apply.
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x-linked / sex traits
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carried on the X chromosome. can be dominant or recessive.
Ex. color blindness and hemophilia |
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pedigrees
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diagrams that show the genetic information of a family tree.
squares are male, circles are female, diamonds are unknown sex. |
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gene pool
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constitutes the total possible assortment of genes found in the population of a species.
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mutation
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the spontaneous addition, transfer, rearrangement, or deletion of one or several nucleotides in a section of DNA.
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evolution
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a change in the genetic makeup of a population.
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fitness (in respect to evolution)
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the ability of an organism's genotype to persevere in subsequent generations.
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speciation
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the evolution of a new species from a preexisting species
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divergent evolution
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when species evolving from the same group maintain a similar structure from the common ancestor.
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reproductive isolation
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insularity of a gene pool from genetic mixing. occurs when two species capable of interbreeding are prevented from doing so.
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adaptive radiation
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when a population experiences change in genotype that render it reproductively isolated from other populations of its parent species --> new species
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adaptive radiation is associated w/... (2 things)
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reduced competition and an alteration of the organism's original niche
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niche
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the organism's "environment", the role it plays
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allopatric speciation
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a form of adaptive radiation. arises through geographic separation.
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sympatric speciation
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a form of adaptive radiation. two closely related populations of one species diverges, such that their differences allow them to exploit different niches w/in the same environment.
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Hardy-Weinberg law
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the occurrence of dominant and recessive alleles w/in a population remains constant over time.
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frequency
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the fractional contribution an allele makes to the total population of both alleles
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p
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the frequency of the dominant allele
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q
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the frequency of the recessive allele
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equations of the Hardy-Weinberg law
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p+q=1
p^2 + pq + q^2 = 1 |
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genetic drift
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the pattern of allele frequency alteration that occurs in small populations. arises by chance.
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taxonomy
|
the classification of organisms
|
|
the order of classification from most comprehensive to most specific:
|
kingdom, phylum, class, order, family, genus, species
|
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chordates
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a phylum identifiable by the presence of a dorsal nerve cord, gill slits, and a notocord.
|
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vertibrates
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chordates recognized by possession of a vertebral column, a closed circulatory system, a developed nervous system, and a developed sensory apparatus
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symbiosis
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a prolonged, intimate association btwn a member of one species and a member of another species
|
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mutualism
|
each partner derives benefit from the association
|
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commensalism
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one partner benefits, other partner neither benefits nor is harmed
|
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ecosystem
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a self-sustaining natural system, composed of both living and nonliving components
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