A A - Science 10science10annas.weebly.com/uploads/2/2/8/9/22894206/heredity_r_and_r1-3_end__some...CHAPTER 2 • How Chromosomes Work SECTION 2 -1 The Chromosome Theory (pages 34-39)

Name ________________ Class ______ Date ___ _

SECTION 1- 3 Genetics and Probability (pages 24-28)

---------KEY CONCEPTS---------A Probability can be used to

predict the results of genetic crosses.

A In addition to probability, a special chart called a Punnett square is used to show the possible gene combinations in a cross between two organisms.

• Building Vocabulary Skills: Analyzing Information

A phenotype refers to ___________________ _

A genotype is the _____________________ _

Using the definitions you stated, answer the questions about the following diagram.

p F1 B B

~ b ... , G>

~~_(~ ~,,._ ...,.....,..-~~''",, ?l .:: et-'''' Bb Bb

X l 1 B ~ ~4, ~ \''• ,,, . ._:;;;,, .... Ji.

BB bb

A A b

B B b b

Bb Bb

1. What are the phenotypes of the parents?

2. What are the genotypes of the parents? ________________ _

3. What are the phenotypes of the offspring? ______________ _

4. What are the genotypes of the offspring? _ ______________ _

© Prentice-Hall, Inc. Heredity: The Code of Life E • 9

' I

F1 F2 B b

B 1 ti'. ._a ~ ~ . f

BB Bb X

--'"'"""'''''' Bb ;;-:- ;r'' ~"·it

A b ( :J i j ( 4'::J, r,i;. B b B b , ... _ ' 4 ..

Bb bb

1. What are the phenotypes of the parents? --- --- --- ---- - -----

2. What are the genotypes of the parents? ___________________ _

3. What are the phenotypes of the offspring? _________________ _

4. What are the genotypes of the offspring? __________________ _

5. How can you explain the fact that the offspring that has a BB genotype and one that has

a.Bb genotype are both black? _____________________ _

6. Can a white offspring be a hybrid? Why? _________________ _

10 • E Heredity: The Code of Life

Name _________________ Class ______ Date ___ _

• Putting It Together: Applying the Main Ideas

Demonstrate your understanding of Punnett squares and probability by completing the test cross in the Punnett square and answering the questions.

p 8

b

X

Bb bb

A A b

B b b b

b

After completing the Punnett square show the relationship between the Punnett square and probability by answering these questions.

1. What is the probability of getting a white offspring from this cross?

2. What is the probability of getting a black purebred offspring from this cross? Note: Read this question carefully and think about it.

3. Can you explain your answer?


Name ________________ Class ______ Date ___ _

REVIEW AND REINFORCEMENT GUIDE CHAPTER 2 • How Chromosomes Work

SECTION 2 -1 The Chromosome Theory (pages 34-39)

--------KEY CONCEPTS--------.._ According to the chromosome

theory, genes are carried from parents to their offspring on chromosomes.

& The main function of chromosomes is to control the production of substances called proteins.

• Building Vocabulary Skills: Making Identifications

Examine the following diagram, then answer the following questions.

Male Female

@ (fil)

i Chromosomes double i @ ® /\ First cell division /\

({j) ® @ ®

I \ I \ Second cell division I \ I \ _!J ~~ _tJ ® @ @ @

I I ~ I I

I I

4 Sperm 1 Egg 3 Polar bodies

1. Identify the process illustrated in the diagram. _______________ _

2. In your own words, describe this process.


Female

Male

4. In your own words, describe these structures.

3. Identify the structures in the diagram to the left.

5. What are the objects identified by letters? ____________ _____ _

6. Explain the function of the objects identified by letters.

• Seeing Relationships: Using the Main Ideas

In your own words, write a complete statement relating each pair of words.

I. Genes, chromosomes

2. Chromosomes, proteins


Name ________________ Class ______ Date ___ _

SECTION 2 _ 2 Mutations (pages 39-43)

---------KEY CONCEPTS--------_. A mutation is a change in a gene or chromosome.

• Buildi'ng Vocabulary Skills: Cause and Effect

The Dutch botanist Hugo De Vries found that once in a while a genetic variation occurred that could not be explained by the laws of genetics. He called these "genetic mistakes"

Factors that l:ause these mistakes, such as radiation and certain

chemicals, are called _______ _

• Seeing Both Sides: Using the Main Ideas

A mutation is a change in a gene or chromosome. Mutations may be harmful or helpful. Complete the following chart showing your understanding of both positive and negative mutations.

MUTATIONS

Type Definition Examples

Harmful

Helpful


Name _________________ Class ______ Date ___ _

SECTION 2 _ 3 The DNA Molecule (pages 44-48)

--------KEY CONCEPTS-------._ DNA stores and passes on genetic information from one

generation to the next.

Building Vocabulary Skills: Understanding Diagrams


Original DNA molecule

DNA molecule unzipping

Two new DNA molecules forming

Two new DNA molecules

1. What is the full name of the molecule shown in the diagram? ________ __ _

2. What is the commonly used name for this molecule? _____________ _

3. Describe the actual shape of the molecule. _________________ _

4. Name the three scientists who shared the Nobel Prize for their work on this molecule.

5. What process is shown in the diagram? __________________ _

6. What is the end result of this process? -----=----------------- - ---


7. In your own words, describe what happens in each step of the process.

a. -----------------------------------

b. - ----------------------------------

c. -----------------------------------

• Analyzing Structure: Understanding the Main Ideas

The passing on of genetic material from one generation to another is closely related to the structure of the DNA molecule. To understand this idea, you must be familiar with the structure of DNA as well as with the process of replication.

DNA consists of a number of units. One of these units is shown in the following diagram. Label _the parts of the unit, then fill in the blanks in the accompanying description.

r---1 I I

Side of DNA ladder - 1 - Rung of DNA ladder - )

I I I I

(Deoxyribose)

The sides of the DNA ladder are made up of molecules of the sugar ________ _

and _ ________ . The rungs of the ladder are formed by pairs of substances

called __________ . The four nitrogen bases in DNA are _____ _

_ _____ , and ______ . Adenine pairs with _____ _

Cytosine pairs with _____ _


Name ________________ Class ______ Date ___ _

SECTION 2 _ 4 How Chromosomes Produce Proteins (pages 49-51)

--------KEY CONCEPTS-------...._ The production of proteins is called protein synthesis.

• Building Vocabulary Skills: Writing Definitions

Write a complete sentence to define each of the following terms.

1. Protein

.2. Synthesis

3. Amino acid

4. Ribonucleic acid (RNA)

• Making Comparisons: Exploring the Main Ideas

Compare DNA and RNA by completing the following table.

Type of Strand Sugar

DNA Double Deoxyribose

RNA

Bases

Adenine, guanine, cytosine, thymine


• Interpreting Illustrations: Exploring the Main Ideas

Examine each of the following diagrams. In the space provided, write a brief explanation of what is occurring in each picture.

DNA

A u

Protein that helps to make RNA

G A C A

Key - Adenine c:::::> Guanine 11111[_ Cytosine - Thymine (DNA only) i;:::t Uracil (RNA only)

... , _______ ..,,- ... --------------Codeword Codeword


Name ________________ Class ______ Date ___ _

Key

t Adenine

e Uracil

g Guanine

• Cytosine

© Prentice-Hall, Inc.

Messenger RNA

Cell structure at which protein-building takes place----

Code word----

Formation of bond between amino acids

~ --L __

Heredity: The Code of Life E • 23

Name ____________ _ ___ Class ______ Date ___ _

REVIEW AND REINFORCEMENT GUIDE CHAPTER 3 • Human Genetics

SECTION 3 _ 1 Inheritance in Humans (pages 58-66)

-=----------KEY CONCEPTS-------A Scientists can now apply some of the basic principles of genetics

to the study of human heredity.

Building Vocabulary Skills: Information from a Punnett Square

The Punnett square pictured below shows a cross between two people. Each person carries one gene for sickle cell hemoglobin and one gene for normal hemoglobin. Examine the Punnett square, then fill in the blanks in the passage that follows.

A s

A AA AS A= gene for normal hemoglobin

S = gene for sickle cell hemoglobin

s AS ss

Each letter represents one member of a gene pair for a specific trait, a type of hemoglobin.

Each of these individual genes is known as an ___________ . The

individuals with the genotype AA have two alleles for ___________ . The AS

individuals have one allele for ___________ and one allele for

___________ . They are said to be ___________ of the sickle

cell trait. The SS individuals have ___________ for sickle cell hemoglobin.

SS individuals have the genetic disorder ___________ . According to the

Punnett square, the children of two carriers of the sickle cell trait have a one-in-four chance

of having the genotype AA, a ______ -in-four chance of having the genotype AS, and

a _____ -in-four chance of having sickle cell anemia.

Because both of the genes that are present are expressed, this type of inheritance is an

example of ___________ . Another example of this type of inheritance

involves __________ _


• Humans Are Special: Understanding the Main Ideas

In many cases of heredity in plants and animals, there are two alleles for a trait. But inheritance is often more complex than that, particularly in humans. How many alleles are

there for human skin color? ___ ____ __________ _____ _ _

How many alleles determine the major human blood groups? _______ ____ _

• Recognizing Interactions: Heredity and Environment

In the space provided, explain in your own words your understanding of how heredity and environment work together.


Name _________________ Class ______ Date ____ _

SECTION 3 _ 2 Sex-Linked Traits (pages 96-69)

--------KEY CONCEPTS-------.._ Traits that are carried on the X chromosome are called sex-linked

traits because they are passed from parent to child on a sex chromosome.

• Building Vocabulary Skills: Explanation Please

The Punnett square below shows the inheritance of colorblindness. Examine the diagram, then answer the questions that follow.

Normal female Normal male - - 0 Sex cells

1. What kind of trait is colorblindness? ___________________ _

2. Why are females less likely than males to be colorblind? ____________ _

3. What is another example of a sex-linked trait? _______________ _

4. What is the difference between a sex-linked trait and a sex-influenced trait?


Name ________________ _ Class ______ Date ___ _

SECTION 3 _ 3 Human Genetic Disorders (pages 70-73)

---------KEY CONCEPTS--------..._ As a result of nondisjunction, body cells receive either more

chromosomes or fewer chromosomes than normal. An abnormal number of chromosomes may result in certain genetic disorders.


Look at the following illustration and answer the questions below.

ll Ah K~ JO 1 2 3 4

n~ ti xi XK 5 6 7 8

i~ ~t ll it 9 10 11 12

di. oil /JA XI 13 14 15 16

xx 14 xx lt 17 18 '\9 20

ll"- ~~

x 4K 21 22

The illustration pictures the size, number, and shape of chromosomes found in a human

organism. What is it called?

If you look carefully at the pairs of chromosomes, you will notice that there is an extra twenty-first chromosome. What condition results from this extra chromosome?

This condition results when a chromosome pair fails to separate during meiosis. What is this

failure called? -------------------- ---------

One method of diagnosing a genetic disorder such as Down syndrome is


• Seeing Connections: Using the Main Ideas

In Section 3-3, you learned that nondisjunction can result in certain genetic disorders because body cells receive either more chromosomes or fewer chromosomes than normal. In the space provided, explain in your own words why you 1.hink Lhis happens.


Name _________________ Class ______ Date ___ _

REVIEW AND REINFORCEMENT GUIDE

CHAPTER 4 • Applied Genetics

SECTION 4 _ 1 Plant and Animal Breeding (pages 80-83)

--------KEY CONCEPTS--------.&. Hybridization is the crossing of

two genetically different but related species of organisms.

A Inbreeding involves crossing plants or animals that have the same or similar sets ~f genes, rather than different genes.

Building Vocabulary Skills: Establishing Relationships

l. Define selective breeding.

2. List some examples of selective breeding.

3. Define hybridization.

4. List some examples of the selective breeding technique known as hybridization.

5. Define inbreeding.

6. List some examples of inbreeding.


m Making Identifications: Using the Main Ideas

Hybridization and inbreeding are two opposite selective breeding processes. Look at each of the following pictures and identify each as an example of hybridization or inbreeding. Place the correct label in the space provided.

Mule Cheetah

\1 I' /"t Ut/, ....

.. !JJ

Racehorse Cultivated Wheat


Name _________________ Class ______ Date ___ _

SECTION 4 _ 2 Genetic Engineering (pages 84-89)

---==-=-,-~-==~-- KEY CONCEPTS-====-----• Genetic engineering is the process in which genes, or pieces of

DNA, from one organism are transferred into another organism.

Building Vocabulary Skills: Labeling the Diagram

The following diagram shows how recombinant DNA is made. Label the diagram, then define the terms that follow.

\ ~

\--

Genetic engineering

Recombinant DNA

Plasmid


• Looking at Applications: Understanding the Main Ideas

The process of genetic engineering has many applications. In the space provided, write a paragraph explaining at least four examples of genetic engineering in the fields of medicine and agriculture. Pick the examples that are interesting to you.


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Name ___ ______ _ ______ Class ______ Date ___ _

REVIEW AND REINFORCEMENT GUIDE CHAPTER 1 • What Is Genetics'!

SECTION 1-1 History of Genetics (pages 12-18)

--------KEYCONCEPTS-------A Genetics is the study of heredity, or tne passing on of traits from

an organism to its offspring.

• Building Vocabulary Skills: Seeing Relationships

When you first begin the ~cudy of genetics, theTe are many new vocabulary words to leaxn so that you may talk about the process of passing characteristics from parents to offspring. It is important chat you understand that all of these tenns are Te lated to one another. Seeing those relationships will help you remember the v,;x:abulary words. To complete the following exercise, look at the two words that are listed and write a statement that shows the relationship betlveen the two words.

l. Traits, genetics Genetics is the study of the passing on of traits from an organism to its

offspring.

2. Genetics, Gregor Mendel Mendel is called the Father of Genetics because of the early wor1c he did in

the study of passing on traits.

3. Genes, a--.uts Genes are the factors passed from parent to offspring that control the

traits of an offspring.

4. Dominant, recessive Dominant 1raits are the strong traits that can "cover" recessive traits and

make them seem to disappear.

O Prentice-Hall. Inc. Heredity: The Cod& of Life E • 5

• Mendel's Peas: Understanding the Main Ideas

You already know that Gregor Mendel is called the Father of Genetics. Look carefully at the illustration below. The steps are pTesented in the correct sequence as they occurred. After you have studied the diagram, write a short par..graph explaining this early 8tudy of heredity. Be sure to include the terms cfontinant and recessive in your expfanation.

Tall

TT

Short

tt

Tall

TI

Tall

TI

Tall

TT

Tall

Tt

Tall

Tt

Short

It

Mendel found that he could 1ransfer pollen from the stamen of one flower to

the pistil of another flower on a different plant. He began his experiments by

first crossing two short pea plants. The offspring were all short plants. He

next crossed tall plants and found that some of the offspring were tall and

some were short. When he crossed a tall plant with a st.tort plant, the first

generation of offspring were all tall but the second generation had some tall

and some short plants. From his ~dies, he coined the words "dominant"

and "recessive." The stronger trait is called the dominant trait while the

weaker trait, the one that seems to disappear, is called the recessive trait.

6 • E Heredity. Ttle Code of Ute

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Name _______________ Class _____ Date ___ _

SECTION 1-2 Principles of Genetics (pag8S 19-23)

--------KEY CONCEPTS--------& Traits, or characteristics, are

passed on from one generation of organisms to the next generation.

.6. The traits of an organism are controlled by genes.

.6. Organisms inherit genes in pairs, one gene from each parent.

.6. Some g!,11es are dominant, whereas other genes are recessive.

.6. Dominant genes hide recessive genes when both are inherited by an organism.

.6. Some genes are neither dominant nor reoessive. These genes show incomplete dominance.

• Building Vocabulary Skills: Labeling Diagrams

After reading Section 1-2, you should be able to label the following diagram with the correct tenns----purebred or hybrid. Be sure you can explain what each term means.

Purebred Hybrid

e PremiO&-HaJI, Inc.

Hybrid

0 ~Floun<l(R)

0 ~ Wrinkled (r)

} Parent cells

} Se• cells

} Possible gene pairs in offspring

Purebred

Heredity: The Cod& of life E • 7

Examine the illustration below. Pictured is an example of incomplete dominance. In your own words, explain this principle of genetics.

lnoomplete dominance means that neither gene in a gene pair masks the

other. As a result, the traits carried by the two genes appear to be blended.

p ,_~ RR (red) Wll(White)

F,

JI ~ ' RW(pink) F/W(pink)

~ . • ~ 11>

'

RW(plnk) RW(pink)

• Reviewing Genetic Principles: Understanding the Main Ideas

Fill in the blanks wi.th the wo.rds that best complete each statement of genetic principle.

1. Traics, or characteristics , are passed on from one generation of organisms to the next generation.

2. The traits of an organism are controlled by genes

3. Org3llisms inherit genes in pairs , one from each parent

4. Some genes are dominant , whereas other genes are recessive .

5. Dominant genes hide recessive genes when both are inherited by an organism.

6. Some genes are neither dominant nor recessive. These genes show

incomplete dominance

8 • E Heredity: n,e Code of Ufe

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Name _____ __________ Class _____ Date ___ _

SECTION 1-3 Genetics and Probability (pages 24-28)

--------KEY CONCEPTS-------A Probability can be used to

predict the results of genetic crosses.

A In addition to probability, a special ·chart called a Punnett square is used to show the possible gene combinations in a cross between two organisms.

a Building Vocabulary Skills: Analyzing Information

A phenotype refers to a visible characteristic

A .....,.. . th actual gene makeup of an organism geno.11

... 1s e _________________ _

Using the definitions you stated, answer the questions about the following diagram.

p F, B B

b

• X ~g • ~ Bb Bb

BB

A B B

bb

A b b

b • ($ Bl> Bl>

l. What are the phenotypes of the parents? One is black and the other white.

?. What are the genotypes of the parents? One is BB and the Othet' is bb.

3. What are the phenotypes of the offspring? All four are black.

4. What are the genotypes of the offspring? All hav;e the genotype Bb.

C Plll<llie&-Hal, Inc. Heredity: The Code of Ufe E • 9

F, F1 B b

B l ~ I ~~ ~

• X ~~ I BS Bb

Bb

BA Bb

b BA b • 1.-7 .. .,.

b

,.. (~JjJ Bb bb

l. What are the phenotypes of the parents? Both are black.

2. What are the genotypes of the parents? Both have the genotype Bb.

3. What are the phenotypes of the offspring? Three are black, one is white.

4. What are the genotype& of the offspring? One is BB, two are Bb, one is bb.

5. How can you explain the fact that the offspring that ha.s a BB genotype and one that has

a Sb genotype are both black? BB is a purebred offspring and Bb is a hybrid

offspring.

6. Can a white offspring be a hybrid? Why? No; because it must have a genotype of bb, which is a purebred.

10 • E Het'edlty: The Code of Life

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Name _________ ______ Class ______ Date ___ _

• Putting It Together: Applying the Main Ideas

Demonstrate your understanding of Punnett squares and probability by completing the test cross in the Punnett square and answering the questions.

p

e )<

Bb

A a b

p '?-; ·-1 ~ 1i. i h 0'1.I

h ... ~~

bb

A b b

F, B B

b Bb bb

b Bb bb

After completing the Punnett sq=e show the relationship between the Punnett square and probability by answering the~e questions.

l. What is the probability of getting a white offspring from this cross?

There is a 50:50 chance, 1/2 (2/4) or 50% chance.

2, What is the probability of getting a black purebred offspring from this cmss? '.'lote: Read this question carefully and think about iL

There is no possibility of getting a purebred black offspring.

3. Can you explain your answer?

Any offspring would get at least one b gene. The only possible purebred

would be bb, or white.

O Prentic~Hall. Inc. Heredity: The Code of Life E • 11

Name _ _ ____ __________ Class _____ _ Date ___ _

REVIEW AND REINFORCEMENT GUIDE CHAPTER 2 • How Chromosomes Worl<

SECTION 2-1 The Chromosome Theory (pages 34--39)

- - ------KEY CONCEPTS--------.a. According to the chromosome

theory, genes are carried from parents to their offspring on chromosomes.

.a. The main function of chromosomes is to oontrol the production of substances called proteins.

• Building Vocabulary Skills: Making Identifications


Male

® i

@

/\ @ ®

Chromosomes oouble

First cell division

Female

(hl)

i ® \

\

@ @

I \ I \ s~~ §

Seoond cell division I \ I \ ® @@ @

½-' _J

4 Sperm 1 Egg 3 Polar bodies

I. Identify the process illustr.ated in the diagram. Meiosis

2. In your own words, describe this process.

Meiosis is a process of cell division that produces the sex cells-the

sperm or egg cells.

C Prentie~Hall, Inc, Heredity: The Code of Life E • 13

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4. In your own words, describe these structures.

3. Identify the structures in the diagram to the lefL

Fruit fly chromosomes

Chromosomes are rod-shaped structures found in the nucleus of a cell.

Chromosomes contain genes and control the production of proteins.

5. What are the objects identified by letters? Sex chromosomes

6. Explain the function of the objects identified by leuers.

Sex chromosomes are the members of the chromosome pair that are

different in males and in females. The X and Y chromosomes in humans

and in fruit flies are sex chrc,_mos~o~m~e~s~·-------------

a Seeing Relationships: Using the Main Ideas

In your own words, write a complete statement relating each pair of words.

1. Cenes, chromosomes

According to the chromosome theory, genes are carried from parents to

their offspring on chromosomes.

~. Chromosomes, proteins

The mairi function of chromosomes is to control the production of

substances called proteins.


Name _ _ _____________ Class _ ____ Date ___ _

SECTION 2 _ 2 Mutations (pages 39-43)

--------- KEY CONCEPTS-------• A mutation is a change in a gene or chromosome.

a Building Vocabulary Skills: Cause and Effect

The Dutch botanist Hugo De Vries found chat once in a while a genetic variation occurred that could not be explained by the laws of genetics. He called these "genetic mi&takes"

mutations Factors that cause these mistakes, such as radiation and certain

chemicals, are called mutagens

a Seeing Both Sides: Using the Main Ideas

A mutation is a change in a gene or chromosome. Mutations may be hannful or helpful. Complete the following chart showing your understanding of both positive and negative mutations.

Type

Harmful

Helpful

o Prentioe-Hall. Inc.

MUTATIONS

Definition

They reduce an organism's chances for survival or reproduction

Cause desirable traits in living things

Examples

Sickle cell anemia

Katahdin potato Seedless navel oranges

Heredity: The Code of life E • 15

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SECTION 2 _ 3 The DNA Molecule (pages 44-48)

--------KEY CONCEPTS--------• DNA stores and passes on genetic information from one

generation to the next.

• Building Vocabulary Skills; Understanding Diagrams

l::xamine the following diagram, then answer the following yucstions.

T

li

r.

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I

I Original DNA molecule

DNA molecule unz,pping

Two new ONA molecules forming

... T

I n :

[½

-Two new DNA molecules

,.,

l. \oVhat is the full name of the molecule shown in the <liagram? _ ________ _

Deoxyribonucleic acid

2. \o\'hat is the commonly used name for this molecule? DNA

3. Describe the actual shape of th.e molecule. A DNA molecule looks like a twisted

ladder or a spiral staircase.

4. Name the three scientists who shared the Nobel Prize for their work on this molecule.

James Watson, Francis Crick, and Maurice Wilkins

5. \,..bat process is shown in the diagram? Replication

6. Vihat is the end result of this process? Two new molecules of DNA are formed,

each of which is an exact duplicate of the original DNA molecule.

© Prentice·Hall, Inc. He.-e<lity: The Code of Life E • 17

7. In your own words, descrihe what happens in each step of the process .

The DNA molecule unzips, separating between the two nitrogen bases a. - ------ - --- ---- --- - - ------ ---

that form each rung of the DNA ladder. This forms two strands.

b. Free nitrogen bases pair up with the nitrogen bases on each DNA

strand.

Once the new bases are attached, two new DNA molecules that are r.. - ----- - --- --- ----- - ------ - -

exact duplicates of the original one are formed.

• Analyzing Structure: Understanding the Main Ideas

The passing on of gen.:tic material from one generation to another is closely related to the structure of the DNA molecule. To unden.tand this idea, you must be familiar with the structure of D:'.llA as well as with the process of replication.

DNA consists ofa num~r of units. One of these unit.~ is shown in the following diagram. Label the par Ls of che unit, then fill in the blanl:.s in the accompanying descriptio,,.

,---- Sid~ of ONA ladder - , - Rung of ONA la(j,:le( -> I I

Phosphate group ~ Nitrogen base

Sugar (Deoxyribose)

. . deoxyribose The sides ot the DNA ladder are made up of molecules of the sugar ____ __ _

and phosphate groups . The rungs of che ladder are formed by pairs of substances

nitrogen bases . . adenine called ____ ___ _ _ . The four nitrogen bases m DNA are ____ _

guanine cytosine d thymine Ad . . .ch thymine , an _____ . enme pairs wi

Cytosine pairs with guanine


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Name _______________ Class _____ Date ___ _

• Search for Understanding: Knowing the Scientists

Each of the following scientists played a role in unlod<lng the genetir. code. Write a statement identifying each scientist.

James Wat.son Watson is an American biologist who shared in the Nobel Prize for his work

on the ONA model.

Rosalind Franklin Franklin was a British scientist who made X-ray photographs of DNA fibers.

ErwinChargaff Chargaff was an American biochemist who analyzed the ONA molecule and

found the proportions of the four bases.

© Prentioe-Hall. lne • Heredity: The Code of Life E • 19

Name ________________ Class ______ Date ___ _

SECTION 2-4 How Chromosomes Produce Proteins (pages 49-51)

--------KEYCONCEPTS-------A The production of proteins is called protein synthesis.

• Building Vocabulary Skills: Writing Definitions

Write a complete sentence to define each of the follo,..ing terms.

I. Protein

Protein is a substance in the body that is necessary for building and

repairing cells.

2. Synthesis

Synthesis is the process of putting together.

3. Arnino acid

Amino acids are the building blocks of proteins.

4. Ribonucleic acid (R.."'IA)

RNA is a genetic messenger similar to DNA.

• Making Comparisons: Exploring the Main Ideas

Compare DNA and R.\:A hy completing !he follm..ing table.

Type of Strand Sugar

DNA Double Deoxyribose

RNA Single Ribose

© Prentice-Hall, Inc,

Bases

Adenine, guanine, cytosine. thymine

Adenine, guanine, cytosine, uracil

Heredity. The Code of Life E • 21

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• Interpreting lllustrati.ons: Exploring 1he Main Ideas

Examine each of the following diagrams. In the space provided, write a brief explanation of what is occurring in each picture.

Key - Adenine c::::> Guonine ~ Cytosine

Thymine (DNA only) Urocil (RNA only)

A strand of RNA GOmplementary to a section of DNA is formed as RNA units

match up wnh DNA units.

Codeworo Cooeworo

Each set of three nitrogen bases in DNA or RNA makes up a code word. A

code word may specify the amino acid 1hat is to be added to the growing

protein chain or may function as a stop or start signal.

22 • E Het-edity. The Code of life

Name __________ _ ____ Class _ ____ Date ___ _

Amino acid

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Key

I Adenine

0 Uracil

8 Guanine

• Cytosine

I Messet>get ANA

Fom\3:tioo of

Transfer RNA reads 1he code on messenger RNA, picks up the amino acids

specified by the coded message, and puts them together in the correct order

in the protein chain.

0 Prenb-Hall. Inc. Het'edity. The Cod& of Life E • 23

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REVIEW AND REINFORCEMENT GUIDE CHAPTER 3 • Hvman G8fl6tics

SECTION 3-1 Inheritance in Humans (pages 58-86)

---------KEY CONCEPTS-------A Scientists can now apply some of the basic principles of genetics

to the study of human heredity.

• Buildin9 Vocabulary Skills: Information from a Punnett Square

The Punnett square pictured below shows a cross between two people. Each person carries one gene for sickle cell hemoglobin and one gene for normal hemoglobin. Examine the Punnen square, then fill in !he blanl,:s in the passage !hat follows.

A s

A AA AS A ~ gene for normal hemoglobin S ~ gene for sickle cell hemoglobin

s AS ss

Each letter represents one member of a gene pair for a specific a-ait, a type of hemoglobin.

Each of d!.ese individual genes is knmvn as an allele . Toe

individuals wid!. !he genotype M have two alleles for normal hemoglobin . The AS

individuals have one allele for normal hemoglobin and one allele for

sickle cell hemoglobin . They are said to be carriers of the sickle

cell trait. Th;: SS individuals have two alleles for sickle cell hemoglobin.

SS individuals have !he genetic disorder sickle cell anemia . According to the

Punnett square, the children of two carriers of the sickle cell trait have a one-in-four chance

of having the genotype M, a two -in-four chance of having the genotype AS, and

a one -in-four chance of having sickle cell anemia.

Because both of the genes that are pres~t are expressed, this type of inheritance is an

example of .codominance . Another example of this type of inheritance

involves ABO blood groups

e Pren1ioe-HaI1, Inc. Hen?dity. The Code of~ E • 25

• Humans Are Special; Understanding the Main Ideas

In man}' cases of heredity in plants and animals, tbere are two alleles for a trait. Bue inheritance is often more complex than that, particularly in humans. How many alleles are

there for human skin color? Three or more

How many alleles determine the major human blood groups? Three

Ill Recognizing Interactions: Heredity and Environment

In the space provided, explain in your own words your understanding of how heredity and environment work together.

Student answers will vary but should include infonnation from the textbook

about the influence of diet ancl other environmental factors. There may also

be information about research done with identical twins.

26 • E Het-edity. The Code of Life

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SECTIOf~ 3 _ 2 Sex-Linked Traits (pages 66--69)

--------KEY CONCEPTS-------.._ Traits that are carried on the X chromosome are called sex-linked

traits because they are passed from parent to child on a sex chromosome.

• Building Vocabulary $kills: Explanation Please

The Punnett square below shows the inheritance of colorblindnei;s. Examine the diagram, then answer the questions that follow.

ti £) Normal female Normal male • ® • 0

Sexoells x:; X"

xC

y

1. What kind ofuail is colorbliPdness? Sex-linked

~- Why are females less likely than males to be colorblind? Because the recessive gene for colorblindness is carried on an X chromosome and females have

two X chromosomes, it is likely that the gene for colorblindness will be

masked by a normal gene. To be colorblind, females must inherit two

recessive genes tor colorblindness. Males only have to inherit one.

3. What is another example of a sex-linked trait? Hemophilia

4. What is the difference between a sex-l.inked trait and a sex-influenced trait?

A sex-influenced trait is a trait that is expressed differently in males than it

is in females and is not caused by genes on the sex chromosomes. A sex

linked trait is caused by genes on the sex chromosomes.

0 Prenace-Hall, Inc. H&redity.: "Ille Code of Life E • 'Z1

Name ________________ Class ______ Date ___ _

SECTION 3 _ 3 Human Genetic Disorders (pages 70-73)

---------KEY CONCEPTS--------• As a result of nondisjunction, body cells receive either more

chromosomes Of' fewer chromosomes than nonnal. An abnormal number of chromosomes may result in certain genetic disorders.


Look al the following illustration and answer the questions below.

}l Ah K~ J! 1 2 3 4

nfi ti Xl Xl 5 6 7 8

i~ XX lX lt 8 10 11 12

,~ ~n a, xx 13 14 15 16

XX II xx it 17 18 19 20

u"' "" X l& 21 22

The illustration pictures the size, number, and shape of c hromosomes found in a human

organism. What is it called? Karyotype

If you look carefully al the pairs of chromosomes, you will notice that theTe is an extra twenty-firsl chromosome. What condition results from this extra chromosome?

Down syndrome

This condition results when a chromosome pair fails to separate during meiosis. What is th.is

failure called? Nondisjunction

One method of diagnosing a genetic disorder such as Down syndrome is

amniocentesis.

@ Prantice-Hall, Inc. Heredity: The Code of Life E • 29

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• Seeing Connections: Using the Main Ideas

In Section 3-3, you learned that nondisjunction can result in certain genetic disorders because body cells receive either more chromosomes or fewer chromosomes than normal. In the space provided, explain in your own words why you think this happens.

Student answers will vary but should reflect the idea that an organism

functions properly with a certain number and size of chromosomes. Any

deviation from this orderly scheme may result in genetic disorders.

30 • E H8"Hity: 'The Code of l.n.

Name ________________ Class ______ Date ___ _

REVIEW AND REINFORCEMENT GUIDE CHAPTER 4 a Appfiec Ge,,etics

SECTION 4-1 Plant and Animal Breeding (pages 8o-83)

---------KEY CONCEPTS--------A Hybridization is the crossing of

two genetically different but related species of organisms.

.t. Inbreeding involves crossing plants or animals that have the same or similar sets of genes, ratner tl'lan different genes.

• Building Vocabulary Skills: Es1ablishing Relationships

I. Define sele.:tive breeding.

Selective breeding is the crossing of plants or animals that have desirable

characteristics to produce offspring with those desirable characteristics.

2. List some examples of selective breeding.

Organisms are produced that are larger in size, provide more food, or are

resistant to certain diseases.

3. Define hybridization.

Hybridization is the crossing of two genetically different but related species

of organisms.

4. List some examples of the selective breeding technique known as hybridization.

Mule, cultivated wheat

5. Define inbreeding.

Inbreeding is a selective breeding technique that is the opposite of

hybridization. It involves crossing plants or animals 1hat have the same or

similar sets of genes rather than different genes.

6. List some examples of inbreeding.

Racehorses, cheetahs

@ Prentioe-Hall, Inc. He.-.idity: The Code of Life E • 31

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• Making Identifications: Using the Main Ideas

Hybridization and inbreeding are two opposite selective breeding processes. Look at each of the following pictures and identify each as an example of hybridization or inbreeding. Place the correct label in the space provided.

Mula Cheetah

Hybridization Inbreeding

Cultivated Wheat

Inbreeding Hybridization


Name ________________ Class ______ Oa!e ___ _

SECTION 4 _ 2 Genetic Engineering (pages '8~)

---------KEY CONCEPTS--------• Genetic engineering is the process in which genes, or pieces of

DNA, from one organism are transferred into another organism.

• Building Vocabulary Skills: labeling the Diagram

The following diagTam shows how recombinant D~A is made. Label the diagram, then define the terms that follow.

DNA from human cell (

Plasmid

f

E.coli

~ Engineered E. coli

\ ~

\ Inserted DNA

0 -. -0 Remov.. 0 Recomt,;nant plasmid SmpJ>:CI DNA

plasmid -=..:..:.:..:.. __ _

Genetic engineering

Reproduced E. coli \ _ , ,

Genetic engineering is the process in which genes, or pieces of DNA, from

one organism are transferred into another organism.

Recombinant DNA

Recombinant DNA is the new piece of combined DNA formed in the process

of genetic engineering when an organism's ONA is joined to the DNA of

another organism.

Plasmid

A plasmid is a ring-shaped piece of DNA.

C Prentice-Hall, Inc. Het'edity: The CO<I& of Life E • 33

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• Lookin9 at Applications: Understanding the Main Ideas

The process of genetic engineering has many applications. [n the space provided, write a paragraph explaining at least four examples of genetic engineering in che fields of medicine and agriculrure. Pick the examples that are interesting to you.

Student answers will vary but should reflect the information in Section 4-2 of

the textbook.

34 • E Het'edtty: The Code of Life

Name ________________ Class ______ Date ___ _

REVIEW AND REINFORCEMENT GUIDE CHAPTER 1 • What Is Genetics?

SECTION 1-1 History of Genetics (pages 12-18)

--------KEY CONCEPTS-------.& Genetics is the study of heredity, or the passing on of traits from

an organism to its offspring.

• Building Vocabulary Skills: Seeing Relationships

When you first begin the study of genetics, there are many new vocabulary words to learn so that you may talk about the process of passing characteristics from parents to offspring. It is important that you understand th~t all of these terms are related to one another. Seeing those relationships will help you remember the vocabulary words. To complete the following exercise, look at the two words that are listed and write a statement that shows the relationship between the two words.

1. Traits, genetics

2. Genetics, Gregor Mendel

3. Genes, traits

4. Dominant, recessive

© Prentice-Hall, Inc. Heredity: The Code of life E • 5

• Mendel's Peas: Understanding the Main Ideas

You already know that Gregor Mendel is called the Father of Genetics. Look carefully at the illustration below. The steps are presented in the correct sequence as they occurred. After you have studied the diagram, write a short paragraph explaining this early study of heredity. Be sure to include the terms dominant and recessive in your explanation.

P generation

Tall

TT

Short

tt

F 1 generation

Tall

Tt


Tall

Tt

F 2 generation

Tall

TT

Tall

Tt

Tall

'rt Short

tt

Documents

A A - Science 10science10annas.weebly.com/uploads/2/2/8/9/22894206/heredity_r_and_r1-3_end__some...CHAPTER 2 • How Chromosomes Work SECTION 2 -1 The Chromosome Theory (pages 34-39)