BIO 111 Rec Quiz 3 (lecture 7, monohybrid crossing lab)

what is the composition of DNA before replication is S phase?

46, one-chromatid chromosome

what is the composition of DNA after replication in S phase?

46, two-chromatid chromosomes

mitosis

the process of separating and segregating the chromatids

what are the events of prophase?

chromosomes condense, nuclear membrane breaks down, two spindle poles divide and migrate to opposite ends of the cell (from those poles, a network of microtubules will grow out from the spindle pores)

what are the events of metaphase?

kinetochore microtubules attach to the kinetochore proteins on the centromeres of the chromosomes and move the chromosomes to the metaphase plate

tubulin

microtubules are hollow tubes composed of this protein

what is each tubulin composed of?

an a and b subunit called a tubulin dimer

function of the - end of microtubule

attached to the spindle pole

function of the + end of microtubule

lengthens by adding more proteins and shortens by shedding tubulin proteins

polymerization

addition of tubulin proteins to the + end which allows microtubules to grow in length

depolymerization

loss of tubulin proteins from the + end which allows microtubules to shorten in length

CEND-E and Dynein

motor proteins located in the kinetochore that keep the chromosomes attached to the + end of the MT as it polymerizes and depolymerizes

what are the events of anaphase

if chromosomes are aligned at the metaphase plate, the anaphase promoting complex (APC) is activated and will destroy the cohesion proteins holding the sister chromatids together, chromosomes are then segregated to opposite ends of the cell by the depolymerization of the kinetochore microtubules

what is the chromosome orientation in anaphase?

each 2-chromatid chromosome becomes two, 1-chromatid chromosome

kinetochore microtubules

connect chromosomes to the spindle poles and segregate the DNA

polar microtubules

extend from spindle pole to spindle pole

aster microtubules

connect spindle poles to cell membrane

what is the movement of anaphase A?

chromosomes move away from each other via depolymerization of kinetochore microtubules

what is the movement of anaphase B?

spindle poles move away from each other via polymerization of polar microtubules

kinesin motor proteins

aid in anaphase B movement by pushing overlapping polar microtubules apart

what are the events of telophase?

nuclear membranes form around each set of chromosomes, chromosomes begin to decondense, spindle apparatus disassembles

homologous chromosomes

pairs of chromosomes in a diploid organism that carry the same genes at the same loci, one inherited from each parent

homozygous

if the two alleles are identical

heterozygous

if the two alleles are different, both a dominant and a recessive allele are present and the dominant allele controls the expression of the trait

phenotype

the observable trait of an organism

if a P value is less than 0.05

reject the hypothesis

if a P value is 0.05 or greater

fail to reject the null hypothesis

monohybrid cross

only one pair of alleles is of interest, the other pairs are considered homozygous