Download Directed Reading B

Name ______________________________ Class___________________Date__________________
Skills Worksheet
Directed Reading B
Section: Meiosis
Circle the letter of the best answer for each question.
1. What are the two kinds of reproduction?
a. chromosomes and offspring
b. heredity and genes
c. asexual and sexual
d. mothers and fathers
ASEXUAL REPRODUCTION
2. What is the name for the way cells divide in asexual reproduction?
a. twins
b. mitosis
c. meiosis
d. homologous
3. How many parent cells are needed in asexual reproduction?
a. one
b. two
c. 100
d. none
SEXUAL REPRODUCTION
4. How are offspring produced that are NOT like either parent?
a. by asexual reproduction
b. by something going wrong
c. by sexual reproduction
d. by mitosis
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
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Heredity
Name ______________________________ Class___________________Date__________________
Directed Reading B continued
Circle the letter of the best answer for each question.
5. What do you call chromosomes that carry the same sets of genes?
a. twin chromosomes
b. homologous chromosomes
c. ordinary chromosomes
d. asexual chromosomes
6. How many chromosomes do human sex cells have?
a. 100
b. 23
c. one
d. none
Meiosis
7. What copying process makes cells with half the usual number of
chromosomes?
a. sex cells
b. meiosis
c. a nucleus
d. mitosis
8. What is made during meiosis?
a. common human cells
b. sex cells
c. genes
d. chromosomes
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
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Heredity
Name ______________________________ Class___________________Date__________________
Directed Reading B continued
Genes and Chromosomes
Circle the letter of the best answer for each question.
9. Where did Walter Sutton suggest that genes are found?
a. on offspring
b. in sex cells
c. in typical cells
d. on chromosomes
THE STEPS OF MEIOSIS
Read the description. Then, draw a line from the dot next to each
description to the matching word.
•
•
•
•
•
•
•
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10. exact copy of a chromosome
11. forms around each new cell
12. when the nucleus divides once
13. divides twice during meiosis
14. the first step in meiosis
15. how chromosomes get ready for
cell to split
16. the last step in meiosis
17. the second step in meiosis
a. nucleus
b. mitosis
c. chromatoid
d. cell membranes
a. four cells formed
from one cell
b. chromosomes line up
at the center of cell
c. chromosomes make
copy of selves
d. chromosomes pair up
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Holt Science and Technology
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Heredity
Name ______________________________ Class___________________Date__________________
Directed Reading B continued
MEIOSIS AND MENDEL
Sex Chromosomes
Read the words in the box. Read the sentences. Fill in each blank with
the word or phrase that best completes the sentence.
Y Chromosome
X chromosomes
hemophilia
meiosis
18. The steps in ______________________explain Mendel’s results.
19. Females have two ______________________, and males have one X and
one Y.
20. When males give a(n) ______________________the offspring will be
male.
21. A sex-linked blood-clotting disorder found mostly in males is
______________________.
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Holt Science and Technology
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Heredity
Name ______________________________ Class___________________Date__________________
Directed Reading B continued
Genetic Counseling
Read the words in the box. Read the sentences. Fill in each blank with
the word or phrase that best completes the sentence.
carriers
selective breeding
recessive
pedigree
22. To trace a family trait through many years, you can use a diagram called a
______________________.
23. A genetic counselor can often predict ______________________of
hereditary diseases.
24. People with cystic fibrosis have two ______________________alleles.
25. Large eggs and large flowers are both created
through______________________.
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Holt Science and Technology
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Heredity