Cell cycle (cytokinesis)

Question 1

final stage in the cell cycle

Answer 1

cytokinesis

Question 2

division of the cytoplasm in two.

Answer 2

cytokinesis

Question 3

some cells undergo ____without cytokinesis and thereby acquire multiple nuclei.

Answer 3

mitosis

Question 4

The first visible change of cytokinesis in an animal cell

Answer 4

appearance of a pucker, or cleavage furrow

Question 5

The structure underlying furrow process

Answer 5

contractile ring

Question 6

As the sister chromatids separate in anaphase, ____ and _____ II begin to
accumulate in the rapidly assembling
contractile ring

Answer 6

actin and myosin II

Question 7

depends on formin (parallel arrays of
linear, unbranched actin filaments)

Answer 7

local formation of actin filaments

Question 8

overlapping arrays of actin and myosin II
filaments ___ to generate the force
that divides the cytoplasm in two

Answer 8

contract

Question 9

persists as a tether between
the two daughter cells and contains the
remains of the central spindle

Answer 9

midbody

Question 10

a large protein structure derived from
the antiparallel interpolar microtubules
of the spindle midzone, packed tightly
together within a dense matrix material

Answer 10

central spindle

Question 11

small GTPase of the Ras superfamily

Answer 11

RhoA

Question 12

controls the assembly and function of the
contractile ring at the site of cleavage

Answer 12

RhoA

Question 13

RhoA promotes:

Answer 13

actin filament formation, myosin II
assembly, and ring contraction at the cell
cortex

Question 14

RhoA stimulates actin filament formation by

Answer 14

activating formins; activating multiple protein
kinase (Rock)

Question 15

must occur only after the two sets of
chromosomes are fully segregated from each other

Answer 15

Cytokinesis

Question 16

must be placed
between the two sets of daughter
chromosomes

Answer 16

site of division

Question 17

depend on
mitotic spindle

Answer 17

correct timing and position

Question 18

during anaphase, the spindle generates
signals that initiate ____ formation at a
position midway between the ____
___

Answer 18

furrow
spindle poles

Question 19

Why cytokinesis also occurs
at the correct time

Answer 19

because dephosphorylation of Cdk substrates, which depends on cyclin destruction in metaphase and anaphase, initiates cytokinesis

Question 20

How does the mitotic spindle specify the site of division?

Answer 20

1. astral stimulation model
2. central spindle stimulation model
3. astral relaxation model

Question 21

astral microtubules carry furrow-inducing
signals

Answer 21

astral stimulation model

Question 22

the spindle midzone, or central spindle,
generates a furrow
-inducing signal that
specifies the site of furrow formation at
the cell cortex

Answer 22

central spindle stimulation model

Question 23

the astral microtubules promote the
local relaxation of actin
–myosin bundles
at the cell cortex

Answer 23

astral relaxation model

Question 24

cortical relaxation is minimal at the
spindle equator; promoting cortical
contraction

Answer 24

astral relaxation model

Question 25

higher-plant cells are enclosed by a semirigid

Answer 25

cell wall

Question 26

the cytoplasm of the plant cell is _____from the ____out by the _____ __ _ ___ ___ ____, called the cell plate, between the two daughter nuclei

Answer 26

partitioned inside construction of a new cell wall ( cell plate)

Question 27

The assembly of the cell plate begins in

Answer 27

late anaphase and is guided by a structure called the phragmoplast

Question 28

contains microtubules derived from the mitotic spindle

Answer 28

phragmoplast

Question 29

each daughter cell must also inherit all of the other essential cell components, including the membrane-enclosed organelles

Answer 29

process of mitosis

Question 30

can arise only by the growth and division of the preexisting organelles.

Answer 30

organelles

Question 31

usually present in large enough numbers;their numbers double once each cycle

Answer 31

mitochondria and chloroplasts

Question 32

cut into two during cytokinesis

Answer 32

ER

Question 33

reorganized and fragmented during mitosis

Answer 33

Golgi apparatus

Question 34

cells divide asymmetrically to produce two cells that ____ in size, in the cytoplasmic contents they inherit, or in both

Answer 34

different

Question 35

the mother cell must first segregate ___ _____ _______ to one side of the cell and then position the ___of ____ so that the appropriate daughter cell inherits these components

Answer 35

cell fate determinants plane of division

Question 36

Some cells undergo multiple rounds of nuclear division without intervening _____ division.

Answer 36

cytoplasmic

Question 37

first 13 rounds of nuclear division occur without cytoplasmic division

Answer 37

Drosophila embryo

Question 38

A cell in which multiple nuclei share the same cytoplasm is called a

Answer 38

syncytium

Question 39

greatly speeds up early development

Answer 39

syncytium

Question 40

membranes are created around each nucleus in one round of coordinated cytokinesis

Answer 40

cellularization

Question 41

Nuclear division without cytokinesis in some types of mammalian cells

Answer 41

megakaryocytes, hepatocytes, heart muscle cells