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120 Cards in this Set
- Front
- Back
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Chromatin
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DNA + Proteins
Condenses to prepare for division Forms thread like chromatin |
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sister chromatids
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have identical DNA, are joined at the centromere
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karyotype
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a photographic inventory of an individuals chromosomes produced from dividing white blood cells
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human karyotype
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23 pairs arranged and numbered. 1-22 are autosomes. X & Y are sex chromosomes.
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autosomes
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homologous chromosomes contains same set of genes
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homologous chromosomes
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are matched in length centromere position.
gene location -alocus is the position of a gene, different versions of a gene may be found at the same locus on maternal and paternal chromosomes. |
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sex chromosomes
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X&Y differ in size and genetic composition. Males Have one X and one Y. Females have two X's.
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somatic cells
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two copies of each chromosomes one from mom & one from dad, called diploid (2N)
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Gamentes
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only have one copy of each chromosome called haploid (1N)
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How many chromosomes have in their somatic cells?
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total of 4
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How many chromatids are present in the karyotype?
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?
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How many pairs of chromosomes do humans have in their somatic cells
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2 pairs
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How many homologous pairs does a female have?
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23
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How many homologous pairs does a male have?
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22
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How did we end up with 2 copies (pairs) of each chromosome?
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we get one half from mom, one half from dad.
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mitosis
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produces genetically identical cells
1 each 2N cell - two N daughter cells that are genetically identical. One N cell - two, One daughter cell that are genetically identical |
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meioses
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Is the process that converts diploid nuclei 2 n To haploid nuclei 1n.
One 2n cell - four, 1n daughter cells that are NOT genetically identical Meioses only occurs in the sex organs producing gametes. |
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daughter cells
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are gametes (sperm & egg)
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fertilization
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the union of sperm 1n and egg 1n to form a zygote 2n
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zygote
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is a diploid cell, it is a fertilized egg that is the beginning stages of a baby.
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organism reproduced by two methods
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a-sexual,
sexual |
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a-sexual reproduction
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offspring are identical to the original cell or organism, involves inheritance of all genes from one parent.
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sexual reproduction
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are similar to parents but show variation of traits, involves inheritance of unique sets of genes from two parents
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How does cell division perpetuate life?
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every cell from a cell,
mitosis, meiosis, |
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What happens in Mitosis during cell division?
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reproduction of an entire single cell organism.
growth of a multi-cellular organism. growth of a fertilized egg to an adult. replacement of cells in an adult. |
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What happens in Meiosis during cell division?
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sperm and egg production.
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binary fusion
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occurs in prokaryotic cells (dividing in half) two identical cells arise from one.
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steps in the process of binary fusion?
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a single circular chromosome duplicates and copies begin to separate from each other.
the cells elongate, and the chromosomal copies separate further. the plasma membrane grows inward to divide the cells. |
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cell cycle
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is an ordered sequence for cell division that consists of two stages,
interface phase, (duplication of cell contents) mitotic phase, (division) |
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Interphase
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the duplication of cell contents
G1-growth, increase in cytoplasm S-duplication of chromosomes (S is synthesis of DNA) G2 - growth, preparation for division |
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mitotic phase
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division
mitosis- division of a nucleus cytokinesis - division of the cytoplasm |
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stages of mitosis
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prophase
pro-metaphase metaphase anaphase telephase |
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mitotic spindle
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divides the chromosomes
is composed of microtubules produced by centrosomes, structures the cytoplasm that organizes microtubule arrangement. contains a pair of centrioles in animals. |
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what changes occur in interphase?
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in the cytoplasm, the cytoplasmic contents double. two centrosomes form.
In the nucleus, the chromosomes duplicate during the S phase nucleoli, sites of ribosomes assembly are visible. |
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What changes occur in prophase?
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in the cytoplasm, microtubules begin to emerge from centrosomes, forming the spindle.
in the nucleus chromosomes coil and become compact, nucleolus disappear. |
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What changes occur in pro-metaphase?
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spindle microtubules reach chromosomes where they attach at kinetochores on the centromeres of the sister chromatids.
Move chromosomes to the center of the cell thru the associated protein motors. The nuclear envelope disappears. |
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What changes occur in metaphase?
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spindle is fully formed. chromosomes align at the cell equator. Kinetochores of sister chromatids are facing the opposite poles of the spindle.
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what changes occur in anaphase?
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sister chromatids separate at the centromeres, daughter chromosomes are moved to the opposite poles of the cell. the cell elongates.
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What changes occur in telephase?
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cell continues to elongate. the nuclear envelope forms around chromosomes at each pole, establishing daughter nuclei. chromatids uncoil, nucleoli reappear, the spindle disappears.
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What changes occur in cytokinesis?
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is divided into separate cells.
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cytokinesis
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in animal cells, a cleavage furrow forms, deepens to separate the contents into two cells.
In plants, a cell plate forms in the middle from vesicles containing cell wall material. the cell plate grows outward to reach the edge, dividing the contents into two cells. each cell has plasma membrane and cell walls. |
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Cell division
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definition -
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Results of Cell division
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are
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compare the types of nuclear division mitosis and meiosis.
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contrast of the types of cell division of mitosis and meiosis.
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distinguish between somatic cell and a gamete-forming (germ) cell.
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distinguish between a-sexual and sexual production.
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a-sexual - self reproducing
sexual - half from mom, half from dad |
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what is the difference between DNA, chromosomes and chromatin?
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Identify a duplicated chromosome with its sister chromatids and centromere.
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Describe the events of a cell cycle of a eukaryotic cell including interphase, mitosis, cytokinesis and make a connection between them.
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Distinguish between the three of interphase, G1, S, G2.
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G1 Cell growing, threads link
S synthesis DNA, chromatin are copied and attached at the centromere G2 - cell grow more, produce enough material to continue on to prophase. |
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Recognize that different species differ in their chromosome number.
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Define Haploid and Diploid number of chromosomes and relate it to the two parents of human offspring.
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State the diploid chromosome number for humans.
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explain the difference between the human sex chromosomes X&Y and the other chromosome pairs?
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describe the process of mitosis including its phases, prophase, anaphase and telephase.
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identify the phases in diagrams and micrographs.
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compare cytokinesis in plants and in animals mitosis.
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define homologous chromosomes (homologous) gene, allele, gametes (egg and sperm) fertilization, zygote
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describe the process of meiosis including its phases (prophase 1, metaphase 1, anaphase 1, telephase 1, prophase 2, metaphase 2, anaphase 2, telephase 2) Identify the phases in diagrams.
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explain how crossing over and the independent orientation of chromosomes contribute to genetic variation of offspring.
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identify and explain the characteristics of cancer cells.
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compare a cancer cell with a normal cell using the example of a normal skin cell with a cancerous skin cell.
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define tumor,
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define benign tumor
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define malignant tumor
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define cancer
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define metastasis
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describe a karyotype and its use
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explain the following structural changes in chromosomes: duplication, inversion, deletion, translocation.
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explain how non disjunction causes changes in chromosome number. Use downs syndrome as an example.
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give example of 6 chromosomal changes in number
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The monomer unit of DNA and RNA is the nucleotide containing
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Nitrogenous base
5-carbon sugar Phosphate group |
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DNA and RNA are polymers of
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nucleotides
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DNA and RNA are polymers called polynucleotides
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-a sugar-phosphate backbone is formed by covalent bonding between the phosphate of one ----
nucleotide and the sugar of the next nucleotide -Nitrogenous bases extend from the sugar-phosphate backbone |
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DNA is composed of two polynucleotide chains joined together by
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hydrogen bonding between bases, twisted into a helical shape
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DNA is composed of two polynucleotide chains joined together byhydrogen bonding between bases, twisted into a helical shape
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-the sugar phosphate backbone is on the outside
-teh nitrogenous base are perpendicular to the backbone in the interior -Specific pairs of bases give the helix a uniform shape -A pairs with T, forming two hydrogen bonds -G pairs with C, forming three hydrogen bonds |
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DNA replication follows a
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semiconservative model
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DNA replication follows asemiconservative model
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-the two DNA strands separate
-each strand is used as a pattern to produce a complementary strand, using specific base pairing -each new DNA helix has one old strand with one new strand |
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DNA replication begins at the orgins of replication
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-DNA unwinds at the origin to produce a bubble
-replication ends when products from the bubbles merge with each other |
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DNA replication occurs in the 5'-3' direction
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-replication is continuous on the 3'-5' template
-replication is discontinuous on the 5'-3' template, forming short segments |
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Enzymes involved in DNA replication
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-DNA polymerases ( adds nucleotides to a growing chain)
-DNA ligase ) joins small fragments into a continuous chain) |
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The DNA genotype is expredded as proteins, which provide the molecular bases for
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phenotypic traits
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A gene is a sequence of DNA that directs the synthesis of a specific protein
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-DNA is transcribed into RNA
-RNA is translated into protein the presence and action of proteins determine the phenotype of an organism |
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Genetic information written in codons is translated into
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amino acid sequences
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The sequence of nucleotides in DNA provides a code for constructing a protein
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-each amino acid is specified by a coon
-64 codons are possible Some amino acids have more than one possible codon |
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Characteristics of the genetic code
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-triplet: three nucleotides specify one amino acid
-61 codons correspond to amino acids AUG codes for methionine and signals the start of transcription - 3 "stop" codons signal the end of translation |
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Transcription produces genetic messages in the form of
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RNA
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Transcription
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-the two DNA strands separate
-one strand is a pattern for producing RNA -for A in DNA, U is replaced in RNA |
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RNA Polymerase
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catalyzes in the reaction
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Stages of transcription
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-initiation:RNA polymerase binds to a promoter, where the helix unwinds and transcription starts
-Elongation:RNA nucleotides are added to the chain -Termination:RNA polymerase reaches a terminator sequence and detaches from the template |
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Eukaryotic messenger RNA (mRNA) undergoes processing before leaving the nucleus
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RNA splicing:removal of introns and joining of exons to produce a continuous coding sequence
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Transfer RNA (tRNA) molecules serve as interpreters during
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translation
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Transfer RNA (tRNA) molecules serve as interpreters during translation
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-transfer RNA (tRNA) molecules match an amino acid to its corresponding mRNA codon
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Ribosomes build
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polypeptides
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Ribosomes carry out translation
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-ribosomes have two subunits;small and large
-each subunit is composed of ribosomal RNAs and proteins -ribosomes have binding sites for mRNA and tRNAs |
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Elongation adds amino acids to the polypeptide chain until a stop codon terminates
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translation
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Elongation adds amino acids to the polypeptide chain until a stop codon terminates translation
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-elongation is the addition of amino acids tot he polypeptide chain
-elongation continues until the ribosome reaches a stop codon -Termination -the completed polypeptide is released -The ribosomal subunits separate _mRNA is released and can be translated again |
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Mutations can change the meaning of genes ( answer on 3)
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a mutation is a change in the nucleotide sequence of DNA
-Base substitution: replacement of one nucleotide with another -effect depends on whether there is an amino acid change that alters the function of the protein 1 of 3 |
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-deletions or intertions
-alter the reading frame of the mRNA, so that nucleotides are grouped in to different codons -lead to significant chages in amino acid sequence downstream of mutation -cause a nonfunctional polypeptide to be produced 2 of 3 |
Mutations can be
-spontaneous: due to errors in DNA replication or recombination -induced by mutagens High energy radiation Chemicals 3 of 3 |
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Nucleic acids are strands of repeated units/monomers. What are the monomers?
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unit of DNA and RNA nucleotides
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A strand of nucleotides has a _________backbone and _______that faces in one direction.
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-----------
----------- |
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The DNA genotype is expredded as proteins, which provide the molecular bases for
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phenotypic traits
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A gene is a sequence of DNA that directs the synthesis of a specific protein
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-DNA is transcribed into RNA
-RNA is translated into protein the presence and action of proteins determine the phenotype of an organism |
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Genetic information written in codons is translated into
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amino acid sequences
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The sequence of nucleotides in DNA provides a code for constructing a protein
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-each amino acid is specified by a coon
-64 codons are possible Some amino acids have more than one possible codon |
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Characteristics of the genetic code
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-triplet: three nucleotides specify one amino acid
-61 codons correspond to amino acids AUG codes for methionine and signals the start of transcription - 3 "stop" codons signal the end of translation |
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Transcription produces genetic messages in the form of
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RNA
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Transcription
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-the two DNA strands separate
-one strand is a pattern for producing RNA -for A in DNA, U is replaced in RNA |
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RNA Polymerase
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catalyzes in the reaction
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Stages of transcription
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-initiation:RNA polymerase binds to a promoter, where the helix unwinds and transcription starts
-Elongation:RNA nucleotides are added to the chain -Termination:RNA polymerase reaches a terminator sequence and detaches from the template |
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Eukaryotic messenger RNA (mRNA) undergoes processing before leaving the nucleus
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RNA splicing:removal of introns and joining of exons to produce a continuous coding sequence
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Homologous chromosomes bear the alleles for each
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charater
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For each pair of homologous chromosomes, alleles of a gene reside at the same locus
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-homozygous individuals have the same allele on both homologues
-heterozygous individuals have a different allele on each homologue |
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The environment affects many characters
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Phenotypic variations are influenced by the environment
-skin color is affected by exposure to sunlight -susceptibility to diseases, such as cancer, has hereditary and environmental components |
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Gregor Mendel
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discovered principles of genetics in experiments with the garden pea
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Mendel showed that
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parents pass heritable factors to offspring
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Advantages of using pea plants
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controlled matings
self fertilization or cross fertilization observable characteristics with two distinct forms ( dominant and recessive phenotypes) True breeding strains ( homozygous for the character being observed) |
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Mendel's law of segregation describes the inheritance of a
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single character
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Example of a monohybrid cross
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Parental generation: purple flower x white flower
-F1 generation: all plants with purple flower -F2 generation: 3/4 purple 1/4 white flowers |
