Meiosis: The Stages

Question 1

What is meiosis?

Answer 1

Meiosis is a form of nuclear division that results in the production of haploid cells from diploid cells

Question 2

What does meiosis produce?

Answer 2

Meiosis produces gametes in plants and animals that are used in sexual reproduction

Question 3

What are the stages of meiosis?

Answer 3

Interphase
Prophase
Metaphase
Anaphase
Telophase

Question 4

What are the two divisions of meiosis?

Answer 4

The two divisions of meiosis are meiosis I and meiosis II

Question 5

What do both divisions have to go through and what does this result in?

Answer 5

Both divisions must go through the stages of meiosis, this results in metaphase I and metaphase II

Question 6

What is interphase?

Answer 6

Interphase is when the cell replicates its chromosomes and checks all of its systems to ensure it is ready to divide

Question 7

During interphase, are chromosomes distinct structures?

Answer 7

During interphase, chromosomes are not visible as distinct structures

Question 8

What occurs in prophase I?

Answer 8

1. In prophase I, chromosomes condense and become visible
2. Homologous chromosomes link together to form bivalents, at this point crossing over is possible
3. The nuclear membrane breaks down and centrioles move to the oopoosite poles of the cell
4. Spindle fibres also start to assemble into the spindle apparatus

Question 9

What occurs in metaphase I?

Answer 9

1. In metaphase I, the pairs of homologous chromosomes bivalents line up along the equator of the spindle apparatus
2. The spindle fibres are attached to the centromeres

Question 10

What occurs in anaphase I?

Answer 10

1.In anaphase I, spindle fibres shorten and homologous chromosomes move towards opposite poles

2.The centromeres do not divide

Question 11

What makes it possible for the homologous chromosomes to move towards the opposite poles?

Answer 11

The homologous chromosomes move towards opposite poles when the chiasmata between the homologous chromosomes breaks down

Question 12

What occurs in telophase I?

Answer 12

1.In Telophase I the chromosome shave now reached the poles of the cell

2.The nuclear membranes reform and the chromosomes uncoil back to their chromatin state

3.The spindle fibres start to break down

Question 13

Before meiosis occurs, what happens first?

Answer 13

Cytokinesis

Question 14

What happens during cytokinesis?

Answer 14

During cytokinesis, the cell divide into two cells

Question 15

These cells are referred to as haploid, why?

Answer 15

These cells are haploid because they no longer contain pairs of homologous chromosomes

Question 16

What occurs in prophase II?

Answer 16

Chromosomes condense becoming visible again, the nuclear membrane breaks down and spindle fibres develop

Question 17

What happens in metaphase II?

Answer 17

The chromosomes line up in a single file along the equator of the spindle apparatus

Question 18

What happens in anaphase II?

Answer 18

1.The centromeres of each chromosome divides and the spindle fibres shorten

2. The chromatids are now pulled towards opposite poles of the cell

Question 19

What happens in telophase II?

Answer 19

1. In telophase II, the chromatids have now reached the poles of the cell
2. The nuclear membranes reform and chromosomes uncoil back to their chromatic state

Question 20

What is the difference between anaphase I and anaphase II?

Answer 20

In anaphase I, the centromere DOES NOT divide. Whereas in anaphase II the centromere of each chromosome DOES divide