NAME ___ANSWER KEY_____________________________________
CH. 10 STUDY GUIDE-REGULAR
SECTION 1: MEIOSIS
In your textbook, read about meiosis I and meiosis II.
Label the diagrams below. Use these choices:
anaphase I
prophase I
1. prophase I
6. telophase I
anaphase II
prophase II
2. prophase II
7. anaphase II
interphase
telophase I
metaphase I
telophase II
3. telophase II
8. metaphase I
metaphase II
4. interphase
5. anaphase I
9. metaphase II
10. Using the pictures & phases above, describe what is happening in each phase:
a. Interphase: G1 – cell grows; S-DNA is duplicated; G2 – cells grows & makes sure all the
organelles are duplicated.
b. Prophase I: nuclear membrane breaks down; nucleolus disappears; centrioles begin to migrate
to opposite sides of the cell; spindle fibers begin to form; homologous chromosomes form;
crossing over occurs
c. Metaphase I: homologous chromosomes are lined up down the middle of the cell
d. Anaphase I: homologous chromosomes are pulled apart & sister chromatids are pulled to
opposite sides of the cell, cell has gone from diploid to haploid
e. Telophase I: nuclear membrane reforms, nucleolus reappears; spindle fibers disappear; cell
divides in 2
f. Prophase II: nuclear membrane breaks down; nucleolus disappears; centrioles begin to migrate
to opposite sides of both cells; spindle fibers begin to form; sister chromatids form
g. Metaphase II: sister chromatids are lined up down the middle of both cells.
h. Anaphase II: sister chromatids are pulled apart & chromosomes are pulled to opposite sides of
both cells
i. Telophase II: nuclear membrane reforms in the 4 cells, nucleolus reappears; spindle fibers
disappear; cell divides into 4 genetically different cells
11. What stage of meiosis will the cell go from diploid (2n) to haploid (n)? anaphase I
12. What is fertilization? Where an egg & sperm cells join creating a diploid cell
13. What is crossing over? Draw a picture. Crossing over is the exchange of genetic
material between 2 homologous chromosomes
14. Explain how crossing over causes genetic variation. Creates different combinations of genes on
chromosomes
15. How many chromosomes are in a typical human body cell? 46
16. How many chromosomes are in a typical egg or sperm cell? 23 = egg; 23=sperm
17. What is the role of the spindle fibers? To move the chromosomes around the cell to allow meiosis to
take place
Complete the table by checking the correct column(s) for each description.
Description
Mitosis
Meiosis
X
18. Involved in the production of gametes
X
19. Involved in growth and repair
X
20. Promotes genetic variation in organisms
21. Consists of one nuclear division
X
22. Produces daughter cells that are genetically identical
X
23. Involves two sets of nuclear divisions
X
24. Produces daughter cells that are not identical
X
25. Results in four haploid gametes
X
26. Also called reduction division
X
SECTION 2: MENDELIAN GENETICS
In your textbook, read about how genetics began and the inheritance of traits.
Write the term or phrase that best completes each statement. Use these choices:
cross-pollination
recessive
dominant
self-fertilization
gametes
trait
inherited
1. Mendel was the first person to succeed in predicting how traits are INHERITED from generation to
generation.
2. In peas, both male and female sex cells, which are called GAMETES, are in the same flower.
3. SELF-FERTILIZATION occurs when a male gamete fuses with a female gamete in the
same flower.
4. Mendel used the technique called CROSS-POLLINATION to breed one plant with another.
5. Mendel studied only one TRAIT at a time and analyzed his data mathematically.
6. In individuals with a heterozygous genotype, the RECESSIVE allele of a trait is hidden by the expression
of the other phenotype.
7. In individuals with a heterozygous genotype, the DOMINANT allele of a trait is visible in the phenotype.
8. Describe heterozygous. When an organism’s chromosomes contain 2 different alleles for a particular
trait
9. Explain why sexual reproduction is better in a frequently changing environment. When the
environment is changing having the greatest genetic diversity ensures that members of the population will
survive.
10. What is phenotype? The observable expression of a trait.
11. What is genotype? The allele pairs of an organism
12. Describe Mendel’s law of independent assortment. Mendelian law stating that a random distribution
of alleles occurs during the formation of gametes.
13. Describe Mendel’s law of segregation. Mendelian law stating that 2 alleles for each trait separate
during meiosis.
In your textbook, read about Punnett squares.
Complete the Punnett square by filling in the missing information.
A student crossed true-breeding pea plants that had purple
flowers (P) with true-breeding pea plants that had white
flowers (p). All of the offspring had purple flowers. Then
the student crossed two plants from the F1 generation. The
student’s Punnett square is shown at right. What information
should the student put in each blank? Remember, the
dominant allele is always written first.
Possible
gametes
14. P
16.
15. P
p
17.
PP
Pp
In your textbook, read about the inheritance of traits and Punnett squares.
Use each of the terms below only once to complete the passage.
dihybrid
gene
genotypes
monohybrid
phenotypic ratio
A cross between plants that involves one characteristic is called a (19) MONOHYBRID
cross. Mendel also performed (20) DIHYBRID crosses, which involve two
(21) GENE pairs, with pea plants. When he crossed two pea plants that
were heterozygous for both seed shape (Rr) and for seed color (Yy), he observed a 9:3:3:1
(22) PHENOTYPIC RATIO among the seeds of the offspring. A Punnett square shows
the possible phenotypes and (23) GENOTYPES of the offspring.
p
Pp
18.
pp
Complete the Punnett square by filling in the missing information.
Possible
gametes
Ry
RY
24.
RY
RRYY
round, yellow
26.
Ry
RRYy
round, yellow
RRYy
round, yellow
27.
RRyy
round, green
30.
rY
RrYY
round, yellow
33.
ry
RrYy
round, yellow
rY
ry
25.
RrYY
RrYy
round, yellow round, yellow
28.
RrYy
round, yellow
31.
29.
Rryy
round, green
32.
RrYy
rrYY
rrYy
round, yellow wrinkled, yellowwrinkled, yellow
34.
35.
36.
rrYy
rryy
Rryy
wrinkled,
yellow
wrinkled,
green
round, green
In your textbook, read about probability.
Refer to the Punnett square above. Respond to the following statement.
37. Find the probability that a wrinkled, green seed will result. 1/16
SECTION 10.3 GENE LINKAGE & POLYPLODY
In your textbook, read about genetic recombination and gene linkage.
Match the definition in Column A with the term in Column B.
Column A
Column B
C
38.genes that are located on the same chromosome
A. chromosome map
A
39.shows the location of several genes
B. genetic recombination
D
40.Drosophila melanogaster
C. linked genes
B
41.an outcome of independent assortment
D. fruit fly
For each statement below, write true or false.
F
42. Crossing over occurs more frequently between genes that are close
together on a chromosome.
F
43. Gene linkage was first studied by using garden peas.
T
44. Scientists call a drawing like the one shown above a chromosome map.
In your textbook, read about polyploidy.
Respond to each statement.
45. Recall the name for the occurrence of one or more extra sets of all the chromosomes
in an organism’s cells.
POLYPLOIDY
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Ch. 10 Study Guide Answer Key