Biology (Holt)

Before You Begin

is the process that results in the pro-

duction of cells with half the normal number

of chromosomes. It occurs in all organisms

that undergo .In this lab,

you will build a model that will help you

understand the events of meiosis. You can

also use the model to demonstrate the effects

of events such as to explain

results such as.

1.Write a definition for each boldface term in

the paragraph above and for the following

terms: homologous chromosomes, gamete.

2.In what organs in the human body do cells

undergo meiosis?

3.During interphase of the cell cycle, how

does a cell prepare for dividing?

4.Based on the objectives for this lab, write a

question you would like to explore about

meiosis.

Procedure

PARTA: Design a Model

1.Work with the members of your lab group

to design a model of a cell using the

materials listed for this lab. Be sure that

your model cell has at least two pairs of

chromosomes.

2.Write out the plan for building your model.

Have your teacher approve the plan before

you begin building the model.

3. Build the cell model your group
   designed. CAUTION: Sharp or
   pointed objects can cause injury. Handle
   scissors carefully. Use your model to
   demonstrate the phases of meiosis. Draw
   and label each phase you model.
   4.Use your model to explore one of the ques-
   tions written by your group for step 4 of
   Before You Begin.Describe the steps you
   took to explore your question.

You Choose

As you design your experiment, decide the following:

a. what question you will explore

b.how to construct a cell membrane

c. how to show that your cell is diploid

d.how to show the locations of at least two

genes on each chromosome

e. how to show that chromosomes are dupli-

cated before meiosis begins

genetic recombination

crossing-over

sexual reproduction

Meiosis

Exploration Lab

Modeling Meiosis

SKILLS

• Modeling


• Using scientific methods

OBJECTIVES

• Describethe events that
  occur in each stage of the
  process of meiosis.


• Relatethe process of meiosis
  to genetic variation.

MATERIALS

• pipe cleaners of at least two
  different colors


• yarn

158 CHAPTER 7Meiosis and Sexual Reproduction

Glass frog with eggs

• wooden beads


• white labels


• scissors

2C 2D 4A 4B 6A 6E