mitosis
list the steps of mitosis in order
prophase, pro-metaphase, metaphase, anaphase, telophase
(PPMAT)
list the steps of meiosis in order
meiosis I - Prophase I, Pro-metaphase I, metaphase I, anaphase I, telophase I
meiosis II - identical to mitosis except occurring twice
describe the difference between genotype and phenotype
genotype - an organisms complete collection of alleles
phenotype - all the traits we can observe in an organism
what are the stages of interphase
G1, S, G2
during which phase does the cleavage furrow start forming
cytokinesis
is the parent cell diploid or haploid?
diploid
how many daughter cells are at the end of meiosis II and what is the chromosome number
- 4 daughter cells at the end
- each haploid with 23 chromosomes
describe the difference between a gene and an allele
gene - individualized sections of DNA
allele - different versions of a gene which determine an organisms different traits
in what stage of the cell cycle does DNA replication occur
S phase
what are sister chromatids
identical copies of DNA held together by the centromere
in what type of cells does mitosis occur?
somatic (body) cells
number of chromosomes at the end of division
23
what is incomplete dominance
when alleles blend together, leading to an expressed trait that is a MIX of the traits associated with each allele
where do cells spend most of their time
in interphase
why does nondisjunction occur
due to the failure of chromosomes to separate in anaphase
what is the purpose of mitosis
- cell growth
- cell repair
- asexual reproduction
describe Mendel's law of independent assortment and what stage of meiosis it takes place in
- the maternal and paternal chromosomes of a homologous pair line up randomly and do not affect the way that any other pair lines up
- metaphase I
what is codominance
instead of mixing together, traits linked to 2 alleles show up separately
a skin cell in G2 of interphase has ___ as much DNA as it had in G1
twice - still has 46 chromosomes but twice the amount of DNA
what is an aster
a radical array of short microtubules that extends from each centrosome
how many daughter cells are made after mitosis and what is the chromosome number like compared to the parent cell
- 2 daughter cells
- same amount of chromosomes, diploid (2n)
describe Mendel's law of segregation and what state of meiosis it occurs in
- when 2 alleles of a gene for a specific trait segregate during anaphase I of meiosis so that each gamete ends up with only 1 allele for each gene
- anaphase I of meiosis
general rules of dominant vs recessive patterns of inheritance in pedigree charts
dominant:
- shows up in every generation
if one parent is affected, roughly half of children will be affected
recessive:
- will skip generations
- it is possible for 2 parents who don't have the trait to have a child with the trait
describe what happens in G1 and G2 of interphase
G1 - cell growth, protein synthesis
G2 - duplication of centrosome, protein synthesis
what is synapsis and what stage does it occur in
synapsis is the act of chromosomes coming togehter
occurs in prophase I of meiosis