Chapter 12

Question 1

Mitotic (M) phase

Answer 1

mitosis and cytokinesis

Question 2

mitosis

Answer 2

the division of the genetic material in the nucleus

Question 3

cytokinesis

Answer 3

the division of the cytoplasm

Question 4

interphase

Answer 4

cell growth and copying of chromosomes in preparation for cell division

Question 5

interphase is about _____ percent of the cell cycle

Answer 5

90

Question 6

G1 Phase

Answer 6

first gap

Question 7

S phase

Answer 7

synthesis (chromosomes are duplicated)

Question 8

G2 Phase

Answer 8

second gap

Question 9

in prophase:

Answer 9

two centrosomes migrate to opposite ends of the cell

Question 10

during prometaphase

Answer 10

some spindle microtubules attach to the kinetochores of chromosomes and begin to move the chromosomes

Question 11

in anaphase:

Answer 11

• the cohesions are cleaved by an enzyme called separase
• sister chromatids separate and move along the kinetochore microtubules toward opposite ends of the cell
• the microtubules shorten by depolymerizing at their kinetochore ends
• nonkinetochore microtubules from opposite poles overlap and push against each other, elongating the cell

Question 12

in telophase:

Answer 12

• genetically identical daughter nuclei form at opposite ends of he cell

Question 13

Cytokinesis begins during:

Answer 13

anaphase or telophase and the spindle eventually disassembles

Question 14

in animal cells, cytokinesis occurs by a process known as cleavage, forming a:

Answer 14

cleavage furrow

Question 15

in plant cells a _____ forms during cytokinesis

Answer 15

cell plate