Download Unit 4 Resources

Teacher Guide & Answers
Extension: Challenge
• Have students do library research on how radiation
causes mutations. Students should choose a
particular type of radiation, such as X rays, cosmic
rays, ultraviolet light, or nuclear radiation, and
report on how it causes mutations and what the
consequences of the mutation are.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Answers to Student Worksheet
1. In the protein showing a point mutation, the
fourth amino acid (glycine in the normal protein)
has been replaced by serine. This change may
make the protein nonfunctional or partially
functional.
2. In the protein showing a frameshift mutation, all
amino acids after the mutation are different from
those in the normal protein chain. This change
almost always produces a nonfunctional protein.
3. The frameshift mutation is likely to have the more
serious effect because so many amino acids may be
affected. In fact, the proteins resulting from such
mutations seldom function. The point mutation
has a less extensive impact on protein structure
and therefore is less likely to interfere with protein
function. However, point mutations have the
potential for causing serious consequences in the
individual organism.
4. A frameshift mutation in which a single base has
been added to a codon would alter subsequent
codons.
5. Chromosomal mutations affect many genes. Also,
chromosomal mutations affect the distribution of
genes to gametes during meiosis. As a result, the
gametes may receive too few or too many genes.
6. Deletion occurs when part of a chromosome is
lost.
7. Insertion results in a duplication of genes on the
same chromosome.
8. Inversion is a chromosomal mutation in which
part of a chromosome breaks off and is reinserted
backwards.
9. Part of one chromosome breaks off and is inserted
into a different chromosome.
Chapter Assessment
Page 73 • Reviewing Vocabulary
1. mRNA
2. frameshift mutation
3. double helix
UNIT 4
4.
5.
6.
7.
8.
9.
10.
11.
12.
nitrogenous bases
replication
codon
tRNA
point mutation
Nondisjunction
translation
chromosomal mutation
cancer
Page 74 • Understanding Main Ideas (Part A)
Codons and nucleotides may vary. Students may represent a codon by circling either 3 bases or 3 nucleotides.
P
codon
S
T
A
S
P
P
S
G
C
S
P
P
S
C
G
S
P
P
S
A
T
S
nucleotide
6.
7.
8.
9.
10.
P
d
c
a
b
c
Page 75 • Understanding Main Ideas (Part B)
1.
2.
3.
4.
5.
a
a
b
a
c
Page 76 • Thinking Critically
1. cytosine; Cytosine is a nitrogen base and it forms
complementary bonds with guanine just as thymine
forms complementary bonds with adenine.
CHAPTER 11 • TEACHER GUIDE & ANSWERS
175
Teacher Guide & Answers
Page 11 • Section 10.2
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
20
10
no
23
meiosis
Interphase
Prophase I
Metaphase I
Anaphase I
Telophase I
Prophase II
Metaphase II
Anaphase II
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
Telophase II
a. Metaphase I
a. Interphase
a. Anaphase I
a. Prophase I
a. Telophase I
true
true
true
false
false
true
Refuerzo y Guía de estudio
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Página 13 • Sección 10.1
1.
2.
3.
4.
5.
6.
7.
8.
9.
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16.
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18.
transmiten
plantas de arveja
gametos
fecundación
polinización cruzada
controló
rasgo
Rr
Yy; amarilla
aa; axial
TT × tt; alta
II; li; hinchada
Tt
toda
verdadero
verdadero
semillas lisas
3/16
20
10
no
23
meiosis
Interfase
Profase I
Metafase I
UNIT 4
14.
15.
16.
17.
18.
19.
20.
21.
Anafase I
Telofase I
Profase II
Metafase II
Anafase II
22.
23.
24.
25.
verdadero
falso
falso
verdadero
Concept Mapping
Page 17 • Mitosis/Meiosis
1.
2.
3.
4.
5.
6.
7.
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13.
body cell
diploid cell
one cell division
two diploid cells
same
chromosomes
gamete-producing cell
diploid cell
two cell divisions
four haploid cells
half
chromosomes
original cell
Problem Solving
Page 18 • Tracing a Family Tree and
Calculating Probabilities
1. Tall parent: TT or Tt. Short parent: tt.
×
short
TT or Tt tall
tt
2. P
1
tall
F1
TT
tall
Tt
Tt
tall
Tt
F2
tall
short
F3
tall
tall
tall
tall
short
tall
tall
tall
short
short
TT
TT
Tt
Tt
tt
TT
Tt
Tt
tt
tt
tt
3. Both plants have only one type of allele for height,
so all progeny will have the same genotype.
4.
GT
Gt
gT
gt
Página 15 • Sección 10.2
1.
2.
3.
4.
5.
6.
7.
8.
b. 3
b. 1
b. 4
b. 2
b. 5
9.
10.
11.
12.
13.
Telofase II
Metafase I; 3
Interfase; 1
Anafase I; 4
Profase I; 2
Telofase I; 5
verdadero
verdadero
GT
Gt
gT
gt
GGTT
GGTt
GgTT
GgTt
GGTt
GGtt
GgTt
Ggtt
GgTT
GgTt
ggTT
ggTt
GgTt
Ggtt
ggTt
ggtt
5. Tall with green pods: 9/16 0.56 100 56%
Tall with yellow pods: 3/16 0.19 100 19%
Short with green pods: 3/16 0.19 100 19%
Short with yellow pods: 1/16 0.06 100 6%
CHAPTER 10 • TEACHER GUIDE & ANSWERS
165
Teacher Guide & Answers
6. In the generation that lacks short plants, the F1
generation, all the plants have the genotype Tt.
Since the allele for tallness is dominant, it masks
the recessive allele for shortness in those plants.
7. Mendel inferred that when the F1 plants produced
gametes, their two alleles, T and t, separated. The
short plants in the F2 generation inherited two
alleles for shortness from the F1 plants.
Basic Concepts Transparency 15
Reteaching Skills Transparency 16
Page 23 • Meiosis
Page 25 • Dihybrid Cross
Purpose
• To show the process of cell division that produces
cells with a haploid number of chromosomes
Teaching Suggestions
• Project the transparency. Remind students that
chromosomes replicate during interphase, which
precedes meiosis. Then have students discuss what is
occurring in each of the phases of meiosis. Explain
that anaphase and telophase are combined into one
diagram in the transparency. Have students identify
which events in the diagram occur in anaphase and
which occur in telophase.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
line up on the equator independently
of each other.
6. The cytoplasm divides in telophase II.
7. If male and female gametes were produced by
mitosis, they would each have the same number of
chromosomes as in the parent cells. When fertilization occurred, the resulting zygote would have
twice the number of chromosomes as the parents.
• Have students discuss how events in anaphase I
of meiosis relate to Mendel’s observation that each
parent donates one allele for each trait at random to
each offspring. This occurs due to the segregation of
homologous chromosomes in anaphase I.
• Discuss how meiosis provides a mechanism for
genetic variation.
Extension: Research
• Have students research sexual reproduction in a variety of organisms, such as paramecia, earthworms,
flowering plants, and amphibians. Students should
note that although the method of sexual reproduction
may vary, each process involves meiosis.
1. TTRR ttrr, or true-breeding tall plants that
always have round seeds crossed with true-breeding
short plants that always have wrinkled seeds
2. TtRr TtRr, or a cross between two plants, each of
which is heterozygous for height and seed shape
3. TR, Tr, tR, tr
4. Nine: TTRR, TTRr, TTrr, TtRR, TtRr, Ttrr, ttrr,
ttRr, ttrr
5. 1/16 TTRR: 2/16 TTRr: 1/16 TTrr: 2/16 TtRR:
4/16 TtRr: 2/16 Ttrr: 1/16 ttRR: 2/16 ttRr: 1/16
ttrr
6. 9:3:3:1, or 9/16 tall, round: 3/16 short, round:
3/16 tall, wrinkled: 1/16 short, wrinkled
7. Answers will vary, but student responses should
show an understanding that the genes for plant
height and seed shape were inherited independently of each other by the plants of the F2 generation. For example, although the F1 plants inherited the alleles for tallness and round seeds from
the one parent and the alleles for shortness and
wrinkled seeds from another parent, some of the
F2 plants are tall and wrinkled.
Reteaching Skills Transparency 17
Page 27 • Mitosis Versus Meiosis
Purpose
Answers to Student Worksheet
1. A sex cell has half the number of chromosomes as
the parent cell.
2. 14
3. four
4. Crossing over occurs in prophase I. During
the process, new combinations of alleles form on
chromosomes.
5. In metaphase I of meiosis, homologous chromosomes line up on the equator in pairs. In
metaphase of mitosis, homologous chromosomes
UNIT 4
• To analyze the similarities and differences between
mitosis and meiosis.
• Skill: Comparing and contrasting
Teaching Suggestions
• Project the transparency with the bottom half covered. Use the diagram of mitosis in the top half of
the transparency to review what students learned
about mitosis in Chapter 8. Then cover the top half
of the transparency and review the diagram of meiosis shown on the bottom half.
CHAPTER 10 • TEACHER GUIDE & ANSWERS
167