BIOL 240 Module 1 Review

prophase

chromosome condensation, centromeres migrate, nucleolus gone

prometaphase

nuclear envelope breakdown, microtubule extension, cohesin binds sister chromatids, chromosomes toward middle

metaphase

fully condensed chromosomes, metaphase plate, sister chromatids attached to kinetochore microtubules, complete mitotic spindle

anaphase

separation via breakdown of sister chromatid cohesion, move toward opposite poles

telophase

nuclear envelope reassembles, chromosome decondensation, cleavage furrow

g2 checkpoint

3rd checkpoint; adequate cell size and successful chromosome replication

metaphase checkpoint

fourth checkpoint; all chromosomes attached to mitotic spindle

g1 checkpoint

first checkpoint; adequate cell size, sufficient nutrient available, growth factors present

s-phase checkpoint

second checkpoint; DNA replication complete, screened to remove base-pair error

prophase 1

duplicated chromosomes, crossing over between non sister chromatids of homologous chromosomes, synaptonemal complex dissolves leaving chiasmata linkage

metaphase 1

tetrads along metaphase plate, kinetochores attach to same centrosome, chiasmata linkage broken

anaphase 1

depolymerization of kinetochore microtubules begins disjunction of homologous chromosomes, moving toward opposite poles

telophase 1

nuclear membranes reform around haploid set of chromosomes

prophase 2

nuclear envelope break down, centrosomes duplicate and migrate, microtubules emanate, chromosome condensation

metaphase 2

sister chromatids attached to kinetochore microtubules, chromosome alignment along metaphase plate

anaphase 2

sister chromatid cohesin breakdown by separase and depolymerization of kinetochore microtubules. nnonkinetochore microtubules polymerize and elongate cell

telophase 2

chromosomes decondense, nuclear envelope reforms

meiosis 1: what separates

homologous chromosomes

meiosis 2: what separtes?

sister chromatids separate

allele definition

type of gene at locus ie eye color

a diploid cell undergoes meiosis I and cytokinesis. the two cells entering prophase II are

haploid

T or F: Haploid cells can undergo mitosis

true

a 2n=8 cell undergoes mitosis and cytokinesis. How many chromosomes are in each daughter cell

8

a 2n=10 cell undergoes meiosis and cytokinesis. how many chromosomes are in each gamete

5

phase of mitosis: microtubules attach to the kinetochores

prophase/prometaphase

chromosomes line up individually in the middle of the cell

metaphase 2

crossing over occurs

prophase I

homologous chromosomes are paired and line up in the middle of the cell

metaphase I

homologous chromosomes separate

anaphase I

sister chromatids separate

anaphase II

a diploid cell undergoes this process and produces diploid cells

mitosis

a diploid cell undergoes this process and produces haploid cells

meiosis

increases genetic variation

meiosis

produces cells genetically different from the parental cell

meiosis

produces identical daughter cells

mitosis

one cell produces four gametes

meiosis

used for asexual reproduction

mitosis

With the following genotypes, which parents and phase of meiosis had a nondisjunction event?
Mom: A, B
Dad: B, C
Child: B, C, C

dad, meiosis II

With the following genotypes, which parent and which phase of meiosis had a nondisjunction event?

Mom: A,C
Dad: B,B
Child: A,B,C

Mom meiosis I

gene defintiion

segment of DNA that encodes a polypeptide/functional molecule

genotype definition

BB, Bb, bb

Phenotype definition

brown eyes

Ratio: Aa x Aa

3:1

Ratio: Aa x aa

1:1

Ratio: Aa x Aa with a recessive lethal

2:1

Ratio: AaBb x AaBb (no gene interaction)

9:3:3:1

Ratio: AaBb x AaBb recessive epistasis

9:3:4

Ratio: AaBb x AaBb dominant epistasis

12:3:1

Ratio: AaBb x AaBb complementary gene interaction

9:7

Ratio: AA x aa

1:0