Meiosis

Question 1

Characteristics of Asexual reproduction

Answer 1

Mitosis
Produces genetically identical offspring
Pro: Rapid and effective
Con: no diversity introduced

Question 2

Characteristics of sexual reproduction

Answer 2

Combination of two haploid sex cells
Fertilisation resulting in a zygote
Meiosis causes change in genetic information

Question 3

Before meiosis, When do chromosomes replicate

Answer 3

In meiotic S phase

Question 4

What happens in meiosis I

Answer 4

Duplicated paternal and maternal homologs pair up
Line up at the equator of the meiotic spindle
Duplicated homologs are pulled apart and segregated into two daughter cells

Question 5

What happens in prophase I

Answer 5

Chromosomes are duplicated
Chromosomes condense and become visible
Synapsis and crossing over occurs
Increases variability in offspring

Question 6

What happens in metaphase I

Answer 6

Homologous chromosomes align at the metaphase plate

Centromeres of the homologous chromosomes are oriented toward the opposite poles

Question 7

What happens in Anaphase I

Answer 7

Microtubules attached to the kinetochores shorten
Homologous chromosomes move to the opposite cell poles
Centromeres do not break

Question 8

What happens in telophase I

Answer 8

Spindle fibre disintegrates and cytokinesis occurs

Each daughter cell has half the number of chromosomes compared to the original

Question 9

Why is genetic variety of meiosis useful?

Answer 9

Produces individuals with novel genetic combinations
Can survive and procreate in an unpredictably variable environment
Provides an efficient way to eliminate harmful mutations form a population