Mitosis and Meiosis Review

Question 1

What is the G2 of interphase?

Answer 1

chromosomes are open meaning you cant see them
-centrosomes (with centriole pairs), chromatin (duplicated)

Question 2

What is prophase?

Answer 2

-cell division & preparation
-chromosomes consisting of two sister chromatids
-DNA doubles then splits in 2

Question 3

What is prometaphase?

Answer 3

-the nuclear envelope breaks down freeing the sister chromatids
-fragments of nuclear envelope show
-kinetochores

Question 4

What occurs in metaphase?

Answer 4

-chromosomes align at the centrosome at one spindle pole
-identical sister chromatids

Question 5

What occurs in anaphase?

Answer 5

-sister chromatids are pulled apart and chromosomes start moving to each end of the cell

Question 6

What occurs in telophase and cytokinesis?

Answer 6

-2 new cells form
-nucleolus form
-nuclear envelope forms

Question 7

What is mitosis?

Answer 7

-paternal and maternal pairs of homologous chromosomes
-cell division initiates packaging into chromosomes while doubling the DNA (wants to double the cell)
-2N=46
-

Question 8

What is Meiosis I?

Answer 8

-segregate the homologous chromosomes
One from mom, one from dad
-join at the interphase plate
-have to look at genes with different chromosomes for the law of independent assortment
-produces many variations in gametes and will separate into respected games
-2N=46

Question 9

What is meiosis II?

Answer 9

-just like mitosis sister chromatids separate
-law of segregation
-four individual chromosomes two paternal (A, A a, a) two maternal
-involves diploid chromosomes
-chance little a is selected in fertilization even though there is a 1/4 chance

Question 10

What occurs when mistakes happen?

Answer 10

-due to chance the sister chromatids don’t separate
-cellular distress can trigger this effect
-both move together N=24 and N=22 (correctly disjoined)
-2nd pair of sister chromatids separate correctly (N=23, N=23)
-non-disjunction occurs
-1/2 chance it has normal progeny
-can be the cause of down syndrome 2N=47

Question 11

What is option #2 for meiosis I?

Answer 11

-each chromosome makes it own decision
-one paternal and one maternal set of chromosomes separates into same dish

Question 12

What occurs in Meiosis I in terms of linkage?

Answer 12

-separate the homologous chromosomes
-higher in gamete pool
-genes are linked because they are on the same chromosome
(AAbb, aaBB)