MOD 3 Meiosis

Question 1

What is the first stage of Meiosis: Interphase

Answer 1

Cell grows and DNA copies it’s self

Question 2

Prophase I

Answer 2

1. Cell grows more
2. DNA is condensed into chromosomes
3. Homologous chromosomes pair up
4. Chromosomes crossover and exchange DNA

Question 3

Metaphase I

Answer 3

1. Homologous pairs of chromosomes go to the metaphase plate (middle line)
2. Centrosome fibre spindles go to each chromosome pair

Question 4

Anaphase 1

Answer 4

1. Centrosome drags homologous chromosomes to opposite poles

Question 5

Telophase I

Answer 5

1. Unfold DNA and reform the nucleus (woven balls)
2. Contractile ring splits into two daughter cells

NOTE: if female, one is bigger than other, if male both are same size

Question 6

What stage does the meiosis process essentially restart?

Answer 6

PII - TII

Question 7

When it is FEMALE, what are the products of Meiosis called?

Answer 7

Biggest = ovum (egg cell)
Smaller ones = polar bodies

Question 8

When it is MALE, what are the products of Meiosis called?

Answer 8

Same size = Spermatids

Question 9

Sister Chromatids

Answer 9

Two identical strands of DNA that formed when DNA replicated during interphase

Question 10

What do the different colour homologous chromosomes mean?

Answer 10

one from mum and one from dad

Question 11

Homologous chromosomes

Answer 11

chromosomes of similar size with a matching set of genes
same genes but not necessarily the same alleles

Question 12

Independent Assortment

Answer 12

The 50/50 chance of which DNA goes up of down

(VARIATION OF CHROMOSOMES OR GENETIC INFORMATION DURING SEX CELL DIVISION)

Question 13

COMPLETE THE GAPS:

Homologous chromosomes have the same ______ but not necessarily the same ______

Answer 13

Homologous chromosomes have the same Genes but not necessarily the same ALLELES.

Question 14

When the genotypes look like this ->

FF gG hH Ii jj Kk

What has happened?

Answer 14

This means genes have been exchanged.

Question 15

What happens if there is missing or insufficient DNA?

Answer 15

Can cause missing or underdeveloped structures

Question 16

How does the cell regulate to make sure there is no missing genetic material?

Answer 16

Checkpoints enure that genetic material has replicated

Question 17

What is the product of meiosis?

Answer 17

Gametes which then can undergo sexual reproduction

Question 18

How to get GENETIC VARIETY?

Answer 18

mutation (anyone with DNA)
independent assortment (in meiosis)
crossing over (in meiosis)
sexual recombination (only in eukaryotic cells)