Lecture 8: The Cell Cycle and Reproduction

Question 1

When cells need to divide, ___ cells undergo mitosis while ___ cells undergo meiosis.

Answer 1

Somatic / Germ

Question 2

What advantage does mitosis have over meiosis?

Answer 2

It allows somatic cells to divide, producing two daugter cells that are genetically identical (genetic uniformity).

Question 3

What advantage does meiosis have over mitosis?

Answer 3

It provides distinct cells, offering genetic diversity.

Question 4

What happens in G1 of interphase?

Answer 4

The cell grows, develops and lives its life

Question 5

What happens in the “S phase” of interphase?

Answer 5

The cell needs to divide, so it makes a copy of its DNA

Question 6

When does DNA replication take place?

Answer 6

The “S” phase of interphase

Question 7

The two halves of this chromosome are attached at the ____.

Answer 7

Centromere

Question 8

How many chromatids do cells have after the “S-phase” of interphase?

Answer 8

92

Question 9

Mitosis is ___ reproduction, and results in ____.

Answer 9

Asexual / two genetically identical cells

Question 10

The nucleus needs to break apart into pieces, and the centrioles spread spindle fibers across the cell. The chromosomes also become visible, because they “wind” together tightly. This occurs in ___ of mitosis.

Answer 10

Prophase

Question 11

In order to split the chromosomes in mitosis, the copies must be pulled apart by centrioles “tugging” on the spindle fibers. This occurs during ___ of mitosis.

Answer 11

Anaphase

Question 12

In order to complete the division of the cell, the membrane begins to pinch off, and the the nucleus of each new cell forms. This occurs in ___ of mitosis.

Answer 12

Telophase

Question 13

In order to split the chromosomes, the spindle fibers arrange the chromosomes and chromatids along the ___ plate.

Answer 13

Metaphase

Question 14

Mitosis (the splitting of cells) is part of interphase in the life cycle of the cell. True or False.

Answer 14

False

Question 15

After mitosis, each of your cells will have ___ chromosomes.

Answer 15

46

Question 16

Where are your germ cells located?

Answer 16

In the ovaries or testes

Question 17

Meiosis I splits ___ apart, resulting in two haploid cells.

Answer 17

Tetrads

Question 18

Meiosis II splits ___ apart, resulting in four haploid cells.

Answer 18

Chromatids

Question 19

Meiosis results in genetic diversity in several ways:

In Prophase I, crossing over can occur.
In Metaphase I, a random arrangement of tetrads occurs.

There is a third way in which sexual reproduction results in genetic diversity. What is it?

Answer 19

Gametes can combine to form zygotes, which is totally random

Question 20

When does crossing over occur?

Answer 20

Prophase 1

Question 21

It is possible for genes to go from one chromosome to another during crossing over. True or False.

Answer 21

True

Question 22

In Meiosis I, tetrads line up along the metaphase plate. There is nothing random about this - they are genetically pre-determined which way they are lined up, on purpose. True or False

Answer 22

False