Download Directed Reading B

Back
Lesson
Print
Name
Class
Date
Skills Worksheet
Directed Reading B
Section: Mendel and His Peas
Circle the letter of the best answer for each question.
1. What is heredity?
a. traits passing from offspring to parents
b. traits passing from parents to offspring
c. offspring with no genotypes
d. traits disappearing in offspring
WHO WAS GREGOR MENDEL?
2. In what country was Gregor Mendel born?
a. United States
b. Austria
c. Germany
d. Italy
3. Where did Gregor Mendel first learn about flowers and fruit trees?
a. in a lab
b. at a college
c. at a monastery
d. on a farm
4. Where did Gregor Mendel do his research?
a. in a lab
b. at a college
c. at a monastery
d. on a farm
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Holt Science and Technology
10
Heredity
Back
Lesson
Print
Name
Class
Date
Directed Reading B continued
UNRAVELING THE MYSTERY
Read the description. Then, draw a line from the dot next to each
description to the matching word.
5. when a plant can fertilize itself
6. when all offspring have the same
traits as the parent
7. when one plant fertilizes another
plant
8. different forms of characteristics
9. used for Mendel’s experiments
10. different forms in a population
•
•
•
•
•
•
a. self-pollinating
b. cross-pollinating
c. true-breeding
a. characteristics
b. traits
c. pea plants
MENDEL’S FIRST EXPERIMENTS
Read the words in the box. Read the sentences. Fill in each blank with
the word or phrase that best completes the sentence.
recessive
dominant
11. A trait always seen in the first generation is the
trait.
12. A trait that reappears in the second generation is the
trait.
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Holt Science and Technology
11
Heredity
Back
Lesson
Print
Name
Class
Date
Directed Reading B continued
MENDEL’S SECOND EXPERIMENTS
Circle the letter of the best answer for each question.
13. What happened in the second generation, when Mendel allowed the
first-generation plants to self-pollinate?
a. The dominant trait disappeared.
b. The recessive trait disappeared.
c. The dominant trait showed up.
d. The recessive trait showed up.
Ratios in Mendel’s experiments
14. What is a ratio?
a. the second generation of a plant
b. the relationship between two different things
c. the cross-pollination of a plant
d. the passing of traits from parents to offspring
Gregor Mendel–Gone but Not Forgotten
15. When did Mendel get the recognition he deserved?
a. more than 30 years after his death
b. the day after he died
c. immediately after his experiments
d. 100 years after his death
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Holt Science and Technology
12
Heredity
Back
Lesson
Print PAGE
TEACHER RESOURCE
25. half the number of chromosomes that
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
were present in the original cell
meiosis
genotype
sex chromosomes
two X chromosomes
one X and one Y chromosome
the X chromosome
the Y chromosome
They are more likely to have a
sex-linked disorder.
Answers will vary. Sample answer:
color blindness and hemophilia
pedigree
carrier
recessive
selective breeding
Directed Reading B
SECTION: MENDEL AND HIS PEAS
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
B
B
D
C
A
C
B
B
C
A
dominant
recessive
D
B
A
Vocabulary and Section
Summary
SECTION: MENDEL AND HIS PEAS
1. heredity: the passing of genetic traits
from parent to offspring
2. dominant trait: the trait observed in
the second generation when parents
with different traits are bred
3. recessive trait: a trait that reappears in
the third generation after disappearing
in the second generation when parents
with different traits are bred.
SECTION: TRAITS AND INHERITANCE
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
C
D
A
D
B
B
C
B
D
B
A
C
B
B
B
B
D
C
D
B
A
C
B
A
D
meiosis
X chromosomes
Y chromosome
hemophilia
pedigree
carriers
recessive
selective breeding
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
SECTION: TRAITS AND INHERITANCE
A
B
C
D
C
A
B
A
D
B
C
1. gene: one set of instructions for an
inherited trait
2. allele: one of the alternative forms of a
gene that governs a characteristic,
such as hair color
3. phenotype: an organism’s appearance
or other detectable characteristic
4. genotype: the entire genetic makeup of
an organism; also, the combination of
genes for one or more specific traits
5. probability: the likelihood that a
possible future event will occur in any
given instance of the event
SECTION: MEIOSIS
1. C
2. B
3. A
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Holt Science and Technology
92
Heredity