3. Mitosis and Meiosis

Question 1

Why is mitosis and meiosis important? What does it allow for?

Answer 1

allows for observation of chromosomes to distinguish size, shape and number
in preparation for mitosis and meiosis, each chr is a double structure composed of a pair of chromatids AKA sister cromatids that are held together @ the centromere

Question 2

What is a dividing cell?

Answer 2

each new cells requires a copy of DNA, prior to division each chr makes exact copy of itself and results in 2 chromatids
in early division stages the sister chromatids remain attached @ centromere and once in separate nuclei they are again referred to as single chr

Question 3

what is karyotype?

Answer 3

a display of a cell’s chr ordered according to size
enables detailed analysis
cells arrested in mid-mitosis
autosomes, sex chr

Question 4

What is chromosome number? How many chr do humans, k9, feL, eq, cow have?

Answer 4

Human -46
k9 - 78
feL - 38
cow - 60

Question 5

Why do mules have an uneven set of chr?

Answer 5

dunno, but they have 63 chr and that is why they are sterile.

Question 6

What are homologous pairs?

Answer 6

chr can be arranged in matching pairs called homologous pairs
they have same size, shape, functions - same genes (but perhaps diff alleles)

Question 7

What is a locus?

Answer 7

chromosomal loc of a specific gene - gene address

Question 8

What is a diploid cell?

Answer 8

Cell w/ 2 sets of chr - maternal/paternal set, 2 copies of every gene, 2n (n= # of chr in 1 set)

Question 9

What is a haploid cell?

Answer 9

cell w/ 1 set of chr - 1 copy of every gene, gametes are 1n

Question 10

What does mitosis/meiosis do in cell division?

Answer 10

mitosis - each cell recieves same # and type of chr as were present in parental cell
meiosis - division resulting in cells w/ half the chr # of parental cell via sexual repro (gametes are haploid (1n), if not, the chr # would doulb every generation