Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
92 Cards in this Set
- Front
- Back
|
Mitosis
|
a nuclear division mechanism that occurs in somatic cells (body cells) of multi-celled eukaryotes
|
|
|
Meiosis
|
precedes the formation of gametes or spores and is the basis of sexual reproduction
|
|
|
Sister chromatids
|
Until the two double-stranded DNA molecules are separated in late nuclear division they are called...
|
|
|
Histones
|
spools of proteins
|
|
|
Nucelosome
|
the smallest unit of structural organization in eukaryotic chromosomes
|
|
|
Centromere
|
when sister chromatids constrict where they attach to one another
|
|
|
Cell cycle
|
series of events from one cell division to the next
|
|
|
Interphase
|
three stages during which a cell increases its mass, roughly doubles its numbers of its cytoplasmic components, and duplicates its DNA (G1, S, G2)
|
|
|
Chromosome number
|
sum of all chromosomes in a cell of a given type
|
|
|
Diploid
|
two of each type of chromosome
|
|
|
Bipolar spindle
|
dynamic network of microtubules that grow from opposite poles of the cell
|
|
|
Prophase
|
the first stage of mitosis; the duplicated chromosomes condense and become threadlike and then rod-shaped; new microtubules also assemble; one of the two centrosomes moves to the opposite pole of the nucleus; bipolar spindle starts
|
|
|
Centrosome
|
region near the nucleus that will organize microtubules while they are forming
|
|
|
Metaphase
|
when all of the duplicated chromosomes are aligned midway between the two spindle poles
|
|
|
Anaphase
|
interval when sister chromatids of each chromosome separate and move toward opposite spindle poles
|
|
|
Telophase
|
one of each type of chromosome reaches a spindle pole; two nuclei form
|
|
|
Contractile ring
|
thin band on actin and myosin filaments wrapped around the cell's midsection
|
|
|
Cell plate
|
fusion of vesicles and their wall-building contents; attaches to the membrane and partitions the cytoplasm
|
|
|
Kinases
|
class of enzymes that activate other molecules by transferring a phosphate group to them; can activate certain proteins in a cascade of signaling events that stops the cell cycle of induces cell death
|
|
|
Growth factors
|
activate genes that stimulate cells to grow and divide
|
|
|
Tumor
|
an abnormal mass neoplasms - abnormal masses of cells that lost control over how they grow and divide
|
|
|
Cancer
|
abnormally growing and dividing cells of a malignant neoplasm; physically and metabolically disrupt surrounding tissues
|
|
|
Asexual reproduction
|
all offspring inherit the same number and kinds of genes from a single parent
|
|
|
Genes
|
sequences of DNA that encode heritable information about traits
|
|
|
Clones
|
genetically identical copies of the parent
|
|
|
Sexual reproduction
|
process involving meiosis, formation of mature reproductive cells called gametes, and then fertilization
|
|
|
Allele
|
each unique molecular form of the same gene
|
|
|
Meiosis
|
nuclear division process that divides the parental chromosome number in half
|
|
|
Gametes
|
mature reproductive cells
|
|
|
Zygote
|
the first cell of a new individual
|
|
|
Homologous chromosomes
|
same length, shape, and assortment of genes in the chromosomes of a pair
|
|
|
Haploid
|
half of the parental chromosome number
|
|
|
Crossing over
|
a process by which a chromosome and its homologous partner exchange corresponding segments
|
|
|
Sporophyte
|
often a diploid and spores form in part of it
|
|
|
Gameotophyte
|
multicelled haploid body inside which one or more gametes form
|
|
|
Sperm
|
type of mature male gamete
|
|
|
Fertilization
|
fusion of the haploid nuclei of two gametes
|
|
|
Genes
|
heritable units of information about traits
|
|
|
Diploid
|
pairs of genes on pairs of homologous chromosomes
|
|
|
Mutation
|
permanent change in a gene that in the information it carries
|
|
|
Hybrids
|
cross between two individuals that breed true for different forms of a trait
|
|
|
Homozygous dominant
|
has pair of dominant alleles (AA)
|
|
|
Heterozygous
|
pair of nonidentical alleles (Aa)
|
|
|
Homozygous
|
pair of recessive alleles (aa)
|
|
|
Gene expression
|
process by which a gene's information is converted to a structural of functional part of a cell
|
|
|
Genotype
|
particular alleles that an individual carries
|
|
|
Phenotype
|
refers to an individual's traits
|
|
|
Monohybrid experiments
|
test for dominant or recessive alleles at one locus
|
|
|
Testcross
|
method of determining genotype in which an individual of an unknown genotype is crossed with another that is homozygous recessive and the results may show if the individual is heterozygous or homozygous for a dominant trait
|
|
|
Mendel's theory of segregation
|
diploid cells have pairs of genes, on pairs of homologous chromosome; the two genes of each pair are separated from each other during meiosis, so they end up in different gametes
|
|
|
Dihybrid experiments
|
test for dominant or recessive alleles at two loci
|
|
|
Mendel's theory of independent assortment
|
as meiosis ends, genes on pairs of homologous chromosomes have been sorted out for distribution into one gamete or another independently of gene pairs on other chromosomes
|
|
|
Codominance
|
nonidentical alleles for a gene are both fully expressed; neither is dominant or recessive in heterozygotes
|
|
|
Multiple-allele systems
|
codominance may occur in which three or more alleles of a gene persist among individuals of a population
|
|
|
Incomplete dominance
|
one allele of a pair is not fully dominant over its partner so the heterozygote's phenotype is somewhere between the two homozygotes
|
|
|
Epistasis
|
interactions among products of two or more gene pairs
|
|
|
Pleiotropy
|
one gene may influence two or more traits
|
|
|
Linkage group
|
all of the genes on a chromosome
|
|
|
Continuous variation
|
range of small differences in most traits among natural populations
|
|
|
Polygenic inheritance
|
the inheritance of multiple genes that affect a trait
|
|
|
Autosomes
|
chromosomes with the same length, shape, and centromere location
|
|
|
Sex chromosomes
|
chromosomes with different length which determine an individual's sex
|
|
|
Karyotype
|
shows whether or not there are extra or missing chromosomes
|
|
|
Duplications
|
DNA sequences that are repeated two or more times; occur during unequal crossovers at prophase I
|
|
|
Deletion
|
loss of some portion of a chromosome
|
|
|
Inversion
|
part of the sequence of DNA within the chromosome becomes oriented in the reverse direction, with no molecular loss
|
|
|
Translocation
|
if a chromosome breaks, the broken part may get attached to a different chromosome or to a different part of the same one
|
|
|
Nondisjunction
|
one or more chromosome pairs do not separate during mitosis or meiosis
|
|
|
Aneuploidy
|
cells have too many or too few copies of a chromosome
|
|
|
Polyploid
|
cells have three or more of each type of chromosome
|
|
|
Pedigrees
|
charts of genetic connections
|
|
|
Syndrome
|
genetic disorder characterized by a specific set of symptoms
|
|
|
Disease
|
illness caused by infection or environmental factors
|
|
|
Bacteriophage
|
type of virus that infects bacteria
|
|
|
DNA polymerase
|
bonds nucleotides together into a new strand according to the order of nucleotides of a template
|
|
|
DNA ligase
|
enzyme that seals any gaps in the new DNA strands
|
|
|
DNA repair mechanisms
|
can fix damaged DNA
|
|
|
Transcription
|
first step in protein synthesis where a sequence of nucleotide bases becomes exposed in an unwound region of a DNA strand; a strand of RNA is synthesized
|
|
|
Messenger RNA (mRNA)
|
carries protein-building codes
|
|
|
Ribosomal RNA (rRNA)
|
becomes part of ribosomes, the structures upon which polypeptide chains are assembled
|
|
|
Transfer RNA (tRNA)
|
delivers amino acids one by one to ribosomes in the order specified by mRNA
|
|
|
RNA polymerase
|
adds the nucleotides one at a time to the end of a growing transcript
|
|
|
Promoter
|
nucleotide sequence when RNA polymerase attaches to its binding site in the DNA
|
|
|
Introns
|
nucleotide sequences that are removed from a new RNA
|
|
|
Exons
|
sequences that stay in the RNA
|
|
|
Codon
|
base triplet in mRNA
|
|
|
Genetic code
|
set of 64 mRNA codons used in protein synthesis
|
|
|
Anticodon
|
a triplet of nucleotides that base-pairs with a complementary mRNA codon
|
|
|
Translation
|
process that coverts genetic information encoded in an mRNA transcript into a new polypeptide chain
|
|
|
Base-pair substitution
|
when wrong nucleotide is paired with an exposed base on a template strand and slips by proofreading and repair enzymes
|
|
|
Insertions or deletions
|
when one or more base pairs are inserted into DNA or deleted from it
|
|
|
Transposable elements
|
segments of DNA that can insert themselves anywhere in a chromosome
|
