Mitosis And Meiosis

Question 1

What is a p arm?

Answer 1

Short arm of chromatid

Question 2

What is the q arm?

Answer 2

Long arm of chromatid

Question 3

What is a telomere?

Answer 3

Repeated sequences at each end of a chromosome or chromatid

Question 4

What is a centromere?

Answer 4

Repetitive sequence that links sister chromatids

Question 5

What are the positions of centromeres called?

Answer 5

Metacentric- middle
Submetacentric
Afrocentric
Telcentric- top

Question 6

How are chromosomes grouped?

Answer 6

According to size and shaped

In groups A-G

Question 7

What is mitosis?

Answer 7

Cell division in somatic cells

Produces two identical daughter cells

Question 8

What tissues is mitosis necessary for?

Answer 8

Epidermis
Mucosae
Bone marrow
Spermatogonia

Question 9

What occurs in prophase?

Answer 9

Spindle fibres appear
chromosomes condense
Nuclear membrane breaks down

Question 10

What occurs in prometaphase?

Answer 10

Spindle fibres attach to chromosomes

Chromosomes condense

Question 11

What happens in metaphase?

Answer 11

Chromosomes align at the equator

Question 12

What happens at anaphase?

Answer 12

Centromeres divide

Sister chromatids move to opposite poles

Question 13

What happens in telophase?

Answer 13

Nuclear membrane reforms
Spindle fibres disappear
Chromosomes decondense

Question 14

What happens in cytokinesis?

Answer 14

Cytoplasm divides

2 genetically identical daughter cells form

Question 15

What are alleles?

Answer 15

Different forms of the same gene

Question 16

Where are chromosomes during interphase?

Answer 16

Chromosome territories

Question 17

What alleles do sister chromosomes have?

Answer 17

The same

Question 18

What is meiosis?

Answer 18

Cell division for germ line cells 
Produces 4 non-identical cells 
Haploid
One round of replication and two rounds of division 
Egg and sperm produced

Question 19

What occurs in prophase I?

Answer 19

Nuclear membrane breaks down
Chromosomes condense
Crossing over occurs

Question 20

What occurs in metaphase I?

Answer 20

Pairs of homologous chromosomes move to the equator of the cell

Question 21

What occurs in Anaphase I?

Answer 21

Homologous chromosomes move to opposite poles of the cell

Question 22

What occurs in telophase I?

Answer 22

Chromosomes gather at poles of the cell

Question 23

What occurs in prophase II?

Answer 23

New spindle forms

Question 24

What occurs in metaphase II?

Answer 24

Chromosomes line up at the equator

Question 25

What happens in anaphase II?

Answer 25

Centromeres divide and chromatids move to opposite poles of the cell

Question 26

What happens in telophase II?

Answer 26

Nuclear envelope reforms

Question 27

How does genetic diversity occur?

Answer 27

Random assortment of chromosomes | Crossing over of genetic material

Question 28

What is spermatogenesis?

Answer 28

Cell division to produce male gametes 1 cell (spermatocyte)- 4 sperm Takes around 60 days

Question 29

What is oogenesis?

Answer 29

Cell division to produce female gametes 1 cell (oocyte) - 1 egg and 3 polar bodies Takes 12-50 years

Question 30

What are the consequences of missegregation in meiosis?

Answer 30

Third of miscarriages Infertility Mental retardation

Question 31

What is non-dysfunction at anaphase?

Answer 31

Where the incorrect number of chromosomes is moved to each pole 1 cell gets 2 chromosomes 1 cell gets 0 chromosomes Leads to aneuploidy

Question 32

What is the format to describe a karyotype?

Answer 32

Chromosome number, sex complement and structural changes separated by commas E.g. 47, XY, +21 Male with trisomy 21

Question 33

What does mitotic dysfunction in first post zygote can division lead to?

Answer 33

One with less chromosomes Usually lost unless involved X

Question 34

If non disjunction occurs in later cell divisions

Answer 34

Leads to mosaic karyotype

Question 35

What is mosaicism?

Answer 35

Presence of two or more cell lines in an individual