8.1.2 Mitosis: An Overview

Question 1

M phase

Answer 1

• the stage of the cell cycle in which cell division takes place. M phase includes mitosis (the division of the
  nucleus) and cytokinesis (the division of the cytoplasm)

Question 2

Mitosis

Answer 2

• a process of nuclear division that involves doubling the DNA so that it can be split to form two sets of DNA,
  one for each resulting cell

Question 3

Chromosomes

Answer 3

• move to the center of the cell and their chromatids are split apart by action of the spindle fibers. Spindle
  fibers are made up of microtubules, which are polymers of tubulin that are able to lengthen and shorten.
• made up of highly condensed DNA that is formed during M phase of the cell cycle. Each chromosome consists of two identical copies of DNA. The two arms of the chromosome are called chromatids, and they
  each represent a copy of the duplicated chromosome. The chromatids are connected to each other at a region called the centromere.
• When the centromere is in the center of the chromosome it is called metacentric. When it is on the edge of the chromosome, it is called telocentric, and when the centromere is between the middle and the edge of the chromosome, it is called acrocentric

Question 4

spindle fibers

Answer 4

• made up of polymers called microtubules. Microtubules are components of the cytoskeleton that are made up of tubulin subunits.
• The spindle fibers attach to the centromere of the chromosome at a region called the kinetochore. Within the kinetochore are motor proteins. These motor proteins are able to depolymerize the microtubules and shorten them, eventually causing the chromatids to separate.

Question 5

Structures that play a role in chromosome movements during cell division are called

Answer 5

• centrosomes

Question 6

A cell containing 12 replicated chromosomes at the beginning of mitosis will have how many chromosomes after the completion of mitosis?

Answer 6

• 12

Question 7

Mitosis is best described as a

Answer 7

• division of the nucleus

Question 8

Spindle fibers attach to the ______________ of a chromosome.

Answer 8

• centromere

Question 9

Which statement regarding chromosomes is false?

Answer 9

• An acrocentric chromosome has its centromere on the end of the chromosome.

Question 10

A replicated chromosome has how many chromatids?

Answer 10

• 2