Meiosis

Question 1

Mitosis

Answer 1

Ways in which somatic (non sex) cells divide

Question 2

Meiosis

Answer 2

a special type of cell division used in sexual reproduction for the formation of gametes

Question 3

Spermatogenesis

Answer 3

production of sperm from germ cells

Question 4

Oogenesis

Answer 4

formation of female gametes (eggs) from ovaries

Question 5

Karyotype
(What phase are karotypes usually found?)

Answer 5

A display of condensed chromosomes arranged in pairs

(Metaphase as they are the most condensed and in sister chromatid pairs)

Question 6

How do you get cells in the right phase of the cell cycle to be able to observe condensed chromosome pairs?

Answer 6

Use a growth factor to stimulate the cell cycle

Question 7

What does a hypotonic solution do to cells?

Answer 7

Makes them swell and easier to rupture to get to condensed chromosomes

Question 8

Why does meiosis reduce the chromosome number in half?

Answer 8

Meiosis creates cells to become gametes (reproductive cells) which will double the number.

Question 9

Interphase (Meiosis)

Answer 9

Chromosomes duplicate becoming sister chromatids and now you have a pair of homologous chromosomes (Diploid)

Question 10

Main idea of Meiosis I

Answer 10

Homologous chromosomes seperate into 2 daughter cells (2 HAPLOID)

Question 11

Main idea of Meiosis II

Answer 11

sister chromatids seperate (4 HAPLOID)

Question 12

Prophase I
(Spindle, chromosomes, nuclear envelope)

Answer 12

• Mitotic spindle forms
• Fragments of nuclear envelope
• crossing over (chiasmata)
• 2 sister chromatids and chromosomes condense

Question 13

Metaphase I
(Spindle, chromosomes, nuclear envelope)

Answer 13

• microtubules attached to kinetochore
• sister chromatids lined up on metaphase plate
• chromosomes line up by homologous pairs
• no nuclear envelope

Question 14

Anaphase I
(Spindle, chromosomes, nuclear envelope)

Answer 14

• Spindle pulls chromosomes to opposite poles
• homologous chromosomes separates
• no nuclear envelope

Question 15

Telophase I and Cytokinesis
(Spindle, chromosomes, nuclear envelope)

Answer 15

• Cleavage furrow forms
• microtubules dissapear but centrosomes are still at opposite poles
  2 haploid cells form
• each chromosome still consists of two sister chromatids
• nuclear envelope reforms

Question 16

What is the difference between Meiosis 1 and Meiosis 2?

Answer 16

• Sister chromatids separate during Anaphase II instead of homologous pairs
• 4 haploid cells result (from 2 prior)

Question 17

What happens when chromosomes fail to separate?

Answer 17

NONDISJUNCTION (different in 1 and 2)
1: homologous chromosomes fail to separate
2. Sister chromatids fail to separate

Question 18

3 ways genetic variability is generated

Answer 18

1. crossing over- results in recombinant chromosomes
2. independent assortment of chromosomes- daughter cells can line up with their sister chromatid or the opposite
3. random fertilization- each male and female gamete represents 2^23*2^23 combinations which is 70 trillion combinations