Name
Date
Reproduction of Organisms
Why do living things reproduce?
Before You Read
Before you read the chapter, think about what you know about why living things reproduce. In the
first column, share three things you already know about this topic. In the second column, identify
three things that you would like to learn more about. When you have completed the chapter, think
about what you have learned and complete the What I Learned column.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
K
What I Know
W
What I Want to Learn
L
What I Learned
Chapter Vocabulary
Lesson 1
Lesson 2
NEW
NEW
sexual reproduction
egg
sperm
fertilization
zygote
diploid
homologous
chromosomes
haploid
meiosis
asexual reproduction
fission
budding
regeneration
vegetative reproduction
cloning
ACADEMIC
potential
REVIEW
DNA
A Lesson Content Vocabulary page for each lesson is provided in the Chapter Resources Files.
Reproduction of Organisms
33
Lesson 1
Sexual Reproduction and Meiosis
Scan Lesson 1. Then write three questions you have about sexual reproduction in your
Science Journal. Try to answer your questions as you read.
What is sexual
reproduction?
I found this on page
117
Model the process of sexual reproduction. Complete the
diagram using these labels:
.
• egg
• sperm
• fertilization
Mother
Egg
• zygote
Father
Fertilization
Sperm
Zygote
Diploid Cells
I found this on page
Detail the relationship between diploid cells and homologous
118
.
chromosomes.
Diploid cells have pairs of chromosomes. These
chromosome pairs, which have genes for the same traits
arranged in the same order, are called homologous
chromosomes.
Haploid Cells
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119
Define haploid cells, and explain how they are produced.
.
Haploid cells are cells that have only one chromosome
from each pair. They are produced through meiosis.
34
Reproduction of Organisms
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
New organism
Lesson 1 | Sexual Reproduction and Meiosis (continued)
The Phases of Meiosis
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
I found this on page
I found this on page
120
121
Model the stages of meiosis I. Draw and describe each stage.
.
.
Stage of
Meiosis I
Drawing
Description
Prophase I
Drawings should
show chromosome
pairs condensed in
the center of a
single cell.
Chromosome pairs
condense in the
center of a single
cell.
Metaphase I
Drawings should
show sister
chromatids lined up
at the center of the
cell.
Sister chromatids
line up at the center
of the cell.
Anaphase I
Drawings should
show sister
chromatids at
opposite ends of the
cell.
Sister chromatids
are pulled to
opposite ends of the
cell.
Telophase I
Drawings should
show cytoplasm
divided around each
set of sister
chromatids, forming
two daughter cells.
The cytoplasm
divides around each
set of sister
chromatids, forming
two daughter cells.
Model the stages of meiosis II. Describe each stage.
Stage of
Meiosis II
Description
Prophase II
Chromosome pairs condense in the center
of a single cell.
Metaphase II
Sister chromatids line up at the center of
the cell.
Anaphase II
Sister chromatids are pulled to opposite
ends of the cell.
Telophase II
The cytoplasm divides around each set of
sister chromatids, forming two daughter
cells.
Reproduction of Organisms
35
Lesson 1 | Sexual Reproduction and Meiosis (continued)
Why is meiosis
important?
I found this on page
Summarize the importance of meiosis.
122
.
Maintains
diploid cells
by
Creates
haploid cells
that
help
making haploid sex
cells that join during
fertilization and form a
diploid zygote
1. maintain the correct
number of
chromosomes in each
generation of offspring
2. provide genetic
variation
I found this on page
123
.
Mitosis has
1
division of
nucleus
2 diploid
daughter cells
produced
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Reproduction of Organisms
Both
have
1 diploid
parent cell
Meiosis has
2
divisions of
nucleus
4 haploid
daughter cells
produced
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Compare and contrast meiosis and mitosis and cell division.
How do mitosis and
meiosis differ?
Lesson 1 | Sexual Reproduction and Meiosis (continued)
Advantages of Sexual
Reproduction
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124
Explain why genetic variation and selective breeding are
advantages of sexual reproduction.
.
Advantage
Sample answers shown.
Disadvantages of Sexual
Reproduction
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
I found this on page
125
.
Explanation
Genetic
variation
Instead of being exact genetic copies of
parents, members of the same species
have different traits, which enable some
of them to survive environmental
changes.
Selective
breeding
The process of choosing and breeding
individuals with desirable traits allows
breeders to create offspring with those
traits.
Identify two main disadvantages of sexual reproduction.
1. takes time
2. takes energy
Explain how the process of meiosis relates to the way in which a child
resembles but is not an exact copy of his or her parents.
Accept all reasonable responses. Student answers should identify observable
characteristics, such as eye color, hair type and color, the shapes of facial features,
and height and build, and attribute the combinations of these to the portions of DNA
inherited from each parent. Students should also indicate that a child does not carry
DNA identical to either parent.
Reproduction of Organisms
37
Lesson 2
Asexual Reproduction
Predict three facts that will be discussed in Lesson 2 after reading the headings. Write your
facts in your Science Journal.
What is asexual
reproduction?
I found this on page
I found this on page
129
129
Identify key points about asexual reproduction. Cross out
the terms that do not apply to the process.
.
.
single parent
organism
fertilization
genetically
identical
meiosis
diploid parent
cells
offspring
produced
2 parent
organisms
haploid
daughter cells
Summarize asexual reproduction in your own words.
Sample answer: In asexual reproduction, one parent
organism produces offspring without going through
meiosis and without fertilization.
I found this on page
Identify the 6 types of asexual reproduction.
130
.
fission
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131
.
mitotic cell
division
I found this on page
131
.
I found this on page
132
.
I found this on page
38
134
.
Reproduction of Organisms
budding
Types of
Asexual
Reproduction
animal
regeneration
cloning
vegetative
reproduction
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Types of Asexual
Reproduction
Lesson 2 | Asexual Reproduction (continued)
I found this on page
130
.
Sequence the steps of cell division through fission.
1. Fission starts with a prokaryote, which does not have a
membrane-bound nucleus.
DNA molecule
2. The prokaryote’s
is copied.
3. The cell grows longer, pulling the two
apart.
copies of DNA
4. The cell membrane pinches inward along the middle of
the cell
5. The cell splits. Two
are formed.
I found this on page
131
.
.
identical daughter cells
Write a complete sentence that defines mitotic cell division
and identifies what type of organism undergoes the process.
Accept all reasonable responses. Sample answer: Mitotic
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
cell division is a form of asexual reproduction in which an
organism, such as a unicellular eukaryote, divides into two
individual offspring through mitosis and cell division.
I found this on page
131
.
Draw a representation of budding. Write a definition of the
term on the lines below your drawing.
Drawings should show a smaller but identical organism
attached to a larger mature organism.
Definition: Sample answer: Budding is the form of asexual
reproduction in which an offspring grows on the body of
its genetically identical parent until it is mature enough to
break off and live on its own.
Reproduction of Organisms
39
Lesson 2 | Asexual Reproduction (continued)
I found this on page
132
.
Explain how animal regeneration can produce two results.
Animal regeneration
produces
organisms
new
new parts of organisms.
.
A complete offspring grows
An organism can grow a
from a piece of a
parent
I found this on page
133
.
new part when a piece
of it is removed
.
.
Identify the structures of plants usually involved in
vegetative reproduction.
roots
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134
.
stems
leaves
Explain how the definition of cloning has changed
over time.
In the past
any process that
produced genetically
identical offspring
I found this on page
134
.
Today
a technique developed
by scientists and
performed in the lab
Identify three advantages of using tissue culture to clone plants.
1. Plant growers can make many copies of plants with
desirable traits.
2. A greater number of plants can be produced more
quickly than by vegetative reproduction.
3. Growers can reproduce plants that have become
infected using disease-free meristem.
40
Reproduction of Organisms
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Cloning
Lesson 2 | Asexual Reproduction (continued)
I found this on page
135
.
Sequence the steps scientists used to produce the cloned sheep,
Dolly.
1. A cell is removed from the first animal. DNA is removed from an
unfertilized egg cell from a second animal.
2. The cells from the two animals are
contains
fused
. The new cell
only DNA from the first animal
.
3. The cell develops into an embryo in the lab.
4.
Embryos are implanted
into the
animal that donated the unfertilized egg.
5. A new individual is born. This individual is an exact genetic
copy of the original animal
.
Classify features of asexual reproduction as advantages
or disadvantages. Write “A” for advantage and “D” for disadvantage
in the center column of the table below. Explain your reasoning in
the right-hand column.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
I found this on page
136
.
Does not require
a mate
A
Because organisms do not need
to search for mates in order to
reproduce, they use less time
and energy.
Can occur rapidly
A
Organisms can reproduce
rapidly, producing a large
number of offspring.
Produces little
genetic variation
D
Less genetic variation within a
species makes it more
vulnerable to environmental
changes.
Use your understanding of asexual reproduction to explain why it is
important that organisms reproduce in a variety of ways.
Accept all reasonable responses. Answers should reflect that a variety of means of
reproduction permits a diverse range of organisms to survive a variety of
environmental challenges.
Reproduction of Organisms
41
Review
Reproduction of Organisms
Chapter Wrap-Up
Now that you have read the chapter, think about what you have learned. Complete the What I
Learned column on the first page of the chapter.
Use this checklist to help you study.
Complete your Foldables® Chapter Project.
Study your Science Notebook on this chapter.
Study the definitions of vocabulary words.
Reread the chapter, and review the charts, graphs, and illustrations.
Review the Understanding Key Concepts at the end of each lesson.
Look over the Chapter Review at the end of the chapter.
Reread the chapter Big Idea and the lesson Key Concepts. Imagine
how the human population would be different if humans reproduced asexually.
Explain how this could be both an advantage and a disadvantage to humans and to
other organisms.
Accept all reasonable responses. Students should observe that asexual
reproduction would result in faster growth of the human population and that the
Challenge Design two models that demonstrate how genetic material is passed from parents to
offspring in meiosis and in mitotic cell division. Present your models to the class, and explain the
processes that they represent.
42
Reproduction of Organisms
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
genetic variation that leads to individuality would diminish.