3.3 and 10.1 Meiosis Flashcards Preview

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Flashcards in 3.3 and 10.1 Meiosis Deck (7)
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1

In what way is meiosis a reduction division?

Meiosis involved a halving of the chromosome number from 2n to n and is thus a reduction.

2

Why is meiosis important to sexually reproducing organisms?

-Halving of chromosome number allows a sexual life cycle with fusion of gametes
-allows for genetic diversity
-fertilization doubles the number of chromosomes each time it occurs so meiosis prevents each generation having double the amount of chromosomes.

3

Are the sister chromatids of one chromosome identical to each other?

Initially, yes, but DNA replication mistakes change that.

4

Are the two homologous chromosomes identical to each other?

No, they are homologous but not identical and so map the same genes but can have different alleles.

5

Define bivalents.

In early stages of meiosis, homologous pairs form bivalents. This consists of four sister chromatids and two homologous chromosomes. Bivalents are also called tetrads.

6

What is the process of forming bivalents called? What occurs then?

It is called synapsis. During this time, crossing over occurs.

7

When does crossing over occur? What is its effect?

-Crossing over occurs during Meiosis I.
-It yields chromatids with new combinations of alleles.