Chapter 13.3

Question 1

What are the two consecutive cell divisions in Meiosis?

Answer 1

Meiosis I and Meiosis II

Question 2

Meiosis I (Reduction Division)

Answer 2

Homologs pair up and separate.

Results in two haploid daughter cells.

Question 3

Meiosis II (Equational Division)

Answer 3

Sister chromatids separate.

Results in 4 haploid cells with unduplicated chromosomes.

Question 4

Sister Chromatids

Answer 4

The identical copies of one chromosome after DNA replication.

Question 5

Tetrad

Answer 5

A pair of homologous chromosomes, which consists of four chromatids.

Question 6

Synapsis

Answer 6

The process where two homologous chromosomes pair together and ailign themselves.

Question 7

Chiasmata

Answer 7

The X-shaped structuers that represent the points of contact between homologous chromosomes.

Question 8

Prophase I

Answer 8

Early Prophase I: Each chromosome pairs with its homolog, creating a tetrad. Non-sister chromatids synapse, and crossing over occurs at the chiasmata.

Question 9

Metaphase I

Answer 9

Pairs of homologs are arranged at the metaphase plate, with one chromosome of each pair facing each pole.

Microtubules attach to the kinetochores of the chromosomes.

Question 10

Anaphase I

Answer 10

Homologs move toward opposite poles.

Question 11

What are the 3 key differences that are unique to Meiosis I?

Answer 11

1. Synapsis and Crossing Over
2. Alignment of homologous pairs at the metphase plate.
3. Separation of homologs.

Question 12

How is Meiosis II similar and different to Mitosis?

Answer 12

The process is identical, but the number of chromosomes is halved.

Question 13

What are errors in meiosis caused by?

Answer 13

Non-Disjunction

Question 14

What results from non-disjunction?

Answer 14

Gametes will have the wrong number of chromosomes – either too many or too few.