mitosis and meiosis

Question 1

What is the short arm of the chromosome called?

Answer 1

p arm

Question 2

What is the long arm of the chromosome called?

Answer 2

q arm

Question 3

What is the telomeric repeat?

Answer 3

TTAGG

Question 4

Name the 4 locations of centromere

Answer 4

metacentric
submetacentric
acrocentric
telocentric ( not in humans)

Question 5

How are chromosomes grouped?

Answer 5

A-G

based on size and shape

Question 6

Where are chromosomes in interphase?

Answer 6

chromosomal territories

Question 7

What are the stages of mitosis?

Answer 7

prophase 
prometaphase 
metaphase 
anaphase 
telophase 
cytokinesis

Question 8

What happens in prophase of mitosis?

Answer 8

nuclear envelope disappears
chromosomes condense
kinetochore recognises centromere

Question 9

What happens in prometaphase of mitosis?

Answer 9

spindles attach

Question 10

What happens in metaphase of mitosis?

Answer 10

chromosomes line up along metaphase plate

Question 11

What happens in anaphase of mitosis?

Answer 11

chromosomes separate - 1 dna molecule to each pole

Question 12

What happens in telophase of mitosis?

Answer 12

cleavage furrow and nuclear envelope forms

Question 13

What happens in cytokinesis?

Answer 13

cell divides

Question 14

What does mitosis produce?

Answer 14

2 identical daughter cells with diploid number of chromosomes

Question 15

What does meiosis produce?

Answer 15

4 non identical cells with haploid number of chromosomes

Question 16

How many DNA replications and cell divisions occur in meiosis?

Answer 16

1 DNA replication followed by two rounds of cell division

Question 17

What happens in prophase I of meiosis?

Answer 17

homologous pairs of chromosomes find each other to form bivalent/tetrad
find each other via homologous regions/ pseudohomology (X&Y)
crossing over can occur at this stage

Question 18

What happens in metaphase I of meiosis?

Answer 18

homologous pairs line up random assortment occurs

Question 19

What happens in anaphase I of meiosis?

Answer 19

homologous pairs separate

Question 20

What happens in telophase I of meiosis?

Answer 20

nuclear envelope form

cleavage

Question 21

What are the products of meiosis I ?

Answer 21

2 non identical diploid cells produced

Question 22

What happens in prophase II?

Answer 22

nuclear envelope disappears

chromosomes condense

Question 23

What happens in metaphase II?

Answer 23

chromosomes line up on metaphase plate

Question 24

What happens in anaphase II?

Answer 24

chromosomes separate

Question 25

What happens in telophase II?

Answer 25

nuclear envelope forms

cleavage

Question 26

what is produced in meiosis II?

Answer 26

4 non identical cells

haploid number fo chromosomes

Question 27

What is the purpose of meiosis?

Answer 27

maintain chromosome number

introduce genetic diversity

Question 28

How is genetic diversity introduced in meiosis?

Answer 28

crossing over

random assortment

Question 29

How many sperm are produced by a primary spermacyte?

Answer 29

4

Question 30

How many eggs are produced by a primary oocyte?

Answer 30

1 oocyte

4 polar bodies

Question 31

What is nondisjunction?

Answer 31

chromosomes do not separate results in aneuploidy

Question 32

What is the standard format for a karotype?

Answer 32

chromosome no., sec complement, structural change

e.g. 47, XY, +21 - Down’s syndrome

Question 33

What happens if non disjunction occurs at first mitotic division?

Answer 33

non-mosaic karotype
all cells have same number of chromosomes
monosomy cell line is usually lost

Question 34

What happens if non-disjunction occurs after first mitotic division?

Answer 34

mosaic karotype