Meiosis Review

Question 1

. Meiosis involves _____ cell divisions with one _____.

Answer 1

two; round of DNA replication

Question 2

During meiosis, the number of chromosomes per cell is reduced to _____: the information
that is lost will be replaced when two such cells, one from each parent, merge.

Answer 2

1/2 of the original number

Question 3

During S phase in the cell cycle, DNA is exactly duplicated so that the cell can divide
without loss of any information. The two duplicate chromosomes that result are called
_____.

Answer 3

sister chromatids

Question 4

Two chromosomes in a single cell that contain the same type of instruction (e.g., eye
color), but not necessarily the same instruction (e.g., brown vs. blue) are said to be _____.
That is, they are _____ of a single chromosome.

Answer 4

homologous; different versions

Question 5

_____ cells contain both homologous chromosomes. (This doesn’t refer to the number of
chromosomes, it refers to the number of _____.)

Answer 5

Diploid; different versions of

each chromosome

Question 6

Haploid cells contain only one _____ of each chromosome (although they may contain
two _____).

Answer 6

version; copies

Question 7

In the first round of division in meiosis, when the chromosomes separate during
anaphase, the _____ separate and the _____ stay together.

Answer 7

homologous chromosomes;

sister chromatids

Question 8

In the second round of division in meiosis, the _____ separate.

Answer 8

sister chromatids

Question 9

In meiosis, during the first prophase, four chromosomes (two copies of each _____) come
together in one place. The cluster is called a(n) _____, and the event is called _____.

Answer 9

homologous chromosome;

tetrad; synapsis

Question 10

During synapsis, homologous chromosomes are broken and patched back together in
such a way that they _____. This is called _____. This gene-shuffling greatly increases
the genetic diversity of the offspring that are produced by sexual reproduction.

Answer 10

exchange pieces; crossing over

Question 11

Synapsis and crossing over occur during _____ .

Answer 11

prophase I (or 'prophase of the 
first division')