Lecture 6: Chromosomes and Mitosis

what is hereditary info found on

genes

where are genes located

on chromosomes

t/f: eggs and sperm contribute equally to the genetics of offspring through their nuclei

true

what are karyotypes

pictures of every chromosome in a cell

what can be seen about chromosomes in karyotypes

how many chromosomes the organism has (including mono/di poloidy, etc), size, number, shape, and banding pattern

how would you expect chromosomes of a diploid organism to appear in a karyotype

in pairs

in what cell phase and in which cells are pictures to be used to make karyotypes taken in

metaphase chromosomes and in somatic cells (NOT GAMETES) → won’t have all the chromosomes (half)

what are autosomes

all chromosomes except x and y (sex chromosomes)

what are sex chromosomes

x and y chromosomes (1 pair in humans)

humans with which chromosomes are assigned male vs female at birth

male - xy

female - xx

t/f: having (only) 2 x chromosomes always means you are born female (across species)

no → sex determination isnt the same in all species

are males or females heterogametic vs homogametic, etc

males - heterogametic

females - homogametic ( 2 of same sex chromosome)

t/f: females are always the homogametic sex

false

t/f: individuals can have more or less than two sex chromosomes

true

what is a good rule of thumb to determine, in humans, if individuals will be male if they have more than one chromosome

as long as there is at least one y, the individual is male

t/f: humans need at least 1 sex chromosome to be viable

true

what are the 2 major processes of cell division

mitosis and meiosise

what is mitosis

nuclear division that results in 2 daughter cells → each containing identical numbers of chromosomes to parent cell

• produces clones of parent cell

what is meiosis

nuclear division that results in 2 daughter cells, each containing half of the number of chromosomes found in other (somatic) cells

produces cells that are unique compared to parent cell