Cytokinesis

How do daughter cells split apart after mitosis?

As a result of mitosis, two nuclei—each with a duplicate set of chromosomes—are formed. All that remains to complete the M phase of the cycle is cytokinesis, the division of the cytoplasm itself. Cytokinesis usually occurs at the same time as telophase. Cytokinesis completes the process of cell division—it splits one cell into two. The process of cytokinesis differs in animal and plant cells.

Cytokinesis in Animal Cells During cytokinesis in most animal cells, the cell membrane is drawn inward until the cytoplasm is pinched into two nearly equal parts. Each part contains its own nucleus and cytoplasmic organelles.

MYSTERY CLUE

The illustration of a salamander with a right hind limb broken off.

How would you expect the salamander's wound to affect the cell cycle in the cells around the wound?

An illustration demonstrating difference in Cytokinesis stage of cell division of animal and plant cells. The difference between them is in animal cell is that the membrane draws inward whereas in a plant cell, a cell plate forms.

FIGURE 10–12 Cytokinesis The division of the cytoplasm occurs differently in animal and plant cells. Draw Conclusions What else, other than cytoplasm, is divided between the two new cells during cytokinesis?

Cytokinesis in Plant Cells Cytokinesis in plant cells proceeds differently. The cell membrane is not flexible enough to draw inward because of the rigid cell wall that surrounds it. Instead, a structure known as the cell plate forms halfway between the divided nuclei. The cell plate gradually develops into cell membranes that separate the two daughter cells. A cell wall then forms in between the two new membranes, completing the process.

10.2 Assessment

Review Key Concepts

    1. Review What are chromosomes?

    2. Compare and Contrast How does the structure of chromosomes differ in prokaryotes and eukaryotes?

    1. Review What is the cell cycle?

    2. Sequence During which phase of the cell cycle are chromosomes replicated?

    1. Review What happens during each of the four phases of mitosis? Write one or two sentences for each phase.

    2. Predict What do you predict would happen if the spindle fibers were disrupted during metaphase?

    1. Review What is cytokinesis and when does it occur?

    2. Compare and Contrast How does cytokinesis differ in animal and plant cells?

WRITE ABOUT SCIENCE

Summary

  1. Summarize what happens during interphase. Be sure to include all three parts of interphase. Hint: Include all of the main details in your summary.

End ofPage 284

Table of Contents

Miller & Levine Biology
About the Authors
Changing the World of Biology Education
Contents
Diversity of Life: A Visual Guide DOL•1–DOL•64
Labs and Activities
Features
UNIT 1 The Nature of Life
1 The Science of Biology
2 The Chemistry of Life
Unit Project
UNIT 2 Ecology
3 The Biosphere
4 Ecosystems and Communities
5 Populations
6 Humans in the Biosphere
Unit Project
UNIT 3 Cells
7 Cell Structure and Function
8 Photosynthesis
9 Cellular Respiration and Fermentation
10 Cell Growth and Division
Unit Project
UNIT 4 Genetics
11 Introduction to Genetics
12 DNA
13 RNA and Protein Synthesis
14 Human Heredity
15 Genetic Engineering
Unit Project
UNIT 5 Evolution
16 Darwin's Theory of Evolution
17 Evolution of Populations
18 Classification
19 History of Life
Unit Project
UNIT 6 From Microorganisms to Plants
20 Viruses and Prokaryotes
21 Protists and Fungi
22 Introduction to Plants
23 Plant Structure and Function
24 Plant Reproduction and Response
Unit Project
UNIT 7 Animals
25 Introduction to Animals
26 Animal Evolution and Diversity
27 Animal Systems I
28 Animal Systems II
29 Animal Behavior
Unit Project
UNIT 8 The Human Body
30 Digestive and Excretory Systems
31 Nervous System
32 Skeletal, Muscular, and Integumentary Systems
33 Circulatory and Respiratory Systems
34 Endocrine and Reproductive Systems
35 Immune System and Disease
Unit Project
A Visual Guide to The Diversity of Life
HOW TO USE THIS GUIDE
THE TREE OF LIFE
Bacteria
Protists
Fungi
Plants
Animals
Appendices
Appendix A Science Skills
Appendix B Lab Skills
Appendix C Technology & Design
Appendix D Math Skills
Appendix E Periodic Table
Glossary
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q, R
S
T
U
V
W
X, Y, Z
Index
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
Credits
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