Mitosis & myosis Flashcards
Parts of an egg
nucleus - cytoplasm- zona pellucida - plasma membrane - cumulus?
frog cell cycle
splits every 15-20 min
Cell theory
all organisms consists of cells
cells divide to produce new cells
higher organisms fuse their cells to produce a new organism
chromatin
combination of protein (especially histones) & DNA
chromatid
1 “mitotic chromosome” has 4 chromatids, connected by a centrosome
Steps in cell division
chromosome replication (s phase) – G2
checkpoint
mitosis or myosis (M) – g1
cytokinesis
mechanism responsible for structure of spindle
polar microtubules attach to each other
ingredients for making a metaphase mitotic spindle
sister chromatids remain paired until all chromatids are attached to a kinetochore microtubule
microtubules grow & shrink until captured by kinetochore
2 kinetochore microtubules from the same spindle cant capture both sister chromatids of a chromosome
checkpoint when metaphase is done (all captured & stable in middle)
Continuous vs discrete variation
height, eye color
independent traits
prob of a wrinkled yellow pea = prob of yellow * pro of wrinkled
mendel’s law irl
represents alleles of same gene on different homologues
also shows independence of traits
also think of female vs male cross chromosomes
Types of alleles
Wild type - predominant, 99%
Mutant allele - change from wild type as a result of recent mutation; also can refer to alleles that causes diseases
Polymorphic allele - contributing to the variation in population
not independent assortment
cross over
Dominant alleles linked in trans or cis
more likely of recombination for closer chromosomes - measure of distance = 100* (# recombination)/(# total progeny) in centiMorgans
semi-dominant trait
3 phenotypes for 1 gene, 2 alleles
–> in population as a whole, more than 2 - continuous traits
ex: alzheimer’s
multigenetic (polygenic)
actual phenotype is the effect of many diff genes - bell type
ex: heart attach
