1. Are an organism's characteristics determined only by its genes? Explain.

Think Critically

  1. Interpret Visuals Genes that control hair or feather color in some animals are expressed differently in the winter than in the summer. How might such a difference be beneficial to the ptarmigan shown here?

A ptarmigan.

11.4 Meiosis

Understand Key Concepts

  1. The illustration below represents what stage of meiosis?

    1. prophase I

    2. anaphase II

    3. telophase I

    4. metaphase I

      An illustration showing Metaphase I stage of cell division.

  2. Unlike mitosis, meiosis in male mammals results in the formation of

    1. one haploid gamete.

    2. three diploid gametes.

    3. four diploid gametes.

    4. four haploid gametes.

  3. A gene map shows

    1. the number of possible alleles for a gene.

    2. the relative locations of genes on a chromosome.

    3. where chromosomes are in a cell.

    4. how crossing-over occurs.

  4. Suppose that an organism has the diploid number 2N = 8. How many chromosomes do this organism's gametes contain?

  5. Describe the process of meiosis.

  6. Explain why chromosomes, not individual genes, assort independently.

Think Critically

  1. Compare and Contrast Compare the phases of meiosis I with the phases of meiosis II in terms of number and arrangement of the chromosomes.

    2. solve the CHAPTER MYSTERY

    A pair of parakeets.

    GREEN PARAKEETS

    After consulting with the owner of the pet store, Susan realized she had a rare gift. White parakeets are very uncommon. The pet shop owner told Susan that two genes control feather color. A dominant Y allele results in the production of a yellow pigment. The dominant B allele controls melanin production. If the genotype contains a capital Y (either YY or Yy) and a capital B, the offspring will be green. If the genotype contains two lowercase y alleles, and a capital B, the offspring will be blue. If the genotype contains two lowercase y's and two lowercase b's, the offspring will be white.

    1. Use Models Draw a Punnett square that accounts for the inheritance of blue pigment.

    2. Use Models Construct a Punnett square that explains the inheritance of a white pigment.

    3. Apply Concepts Solve the mystery by determining the genotypes and phenotypes of the parents and offspring.

    4. Connect to the What ratio of colored offspring would you expect if Susan breeds her original pair of parakeets in the years ahead? Would any offspring be green?

End ofPage 333

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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