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AP Biology
Sexual Reproduction and Inheritance
Reading Guide – Chapters 7.1, 7.4, 8.4
Meiosis and Asexual vs. Sexual Reproduction
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OBJECTIVES
 Understand the significance of sexual versus asexual reproduction in terms of genetic variation.
 Describe alternation of generations and the basic life cycle of an animal, plant, fungus, and asexual
organism. Review reproductive cycle in angiosperms.
 Understand how meiosis contributes to genetic variation.
 Describe what is meant by independent assortment.
 Describe the phases of meiosis in detail.
 Relate the phase of meiosis with the events of cross-over, independent assortment and reduction in
chromosome number.
 Compare and contrast meiosis and mitosis.
 Explain the human life cycle and the production of gametes by spermatogenesis and oogenesis.
 Distinguish among nondisjunction, aneuploidy, and polyploidy; explain how these major
chromosomal changes occur and describe the consequences.
 Distinguish between monosomy and trisomy; provide examples of genetic disorders association
with these conditions.
 Distinguish among deletions, duplications, translocation, and inversion; explain how these changes
can occur and provide examples of genetic disorders associated with each event.
 Describe the type of chromosomal alterations implicated in the following human disorders; Down
Syndrome, Klinefelter syndrome, Turner syndrome
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Reviewing Sexual Life Cycles
1.
Sketch out the three life cycles given in Figure 7.3 (haplontic, alternation of generations; and
diplontic). Give two examples of organisms that undergo each life cycle.
2.
In animals, haploid cells become __________________________, in plants they become
_________________________.
3.
In a plant life cycle, what happens to the haploid spores that are produced as a result of
meiosis?
a. How does the next generation produce gametes?
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AP Biology
Sexual Reproduction and Inheritance
Reading Guide – Chapters 7.1, 7.4, 8.4
4.
Review the reproductive cycle of angiosperms. Answer the following:
a. Where are male pollen grains formed? Where are eggs formed?
b. How do plants prevent self-pollination?
c. Describe the roles of the two sperm nuclei in double fertilization.
QUESTIONS – Section 7.4: Meiosis
5.
What is the primary mechanism for generating variation in the offspring asexually reproducing
organisms?
6.
Why is this sufficient for these organisms?
7.
Define sexual reproduction. What is the advantage of sexual reproduction?
8.
What is the greatest source of variation in sexually reproducing organisms?
9.
Why is meiosis necessary in organisms that reproduce sexually?
10.
Explain homologous chromosomes – what are the origins of homologous chromosomes? Are
homologous chromosomes identical?
11.
Define:
HOMOLOGUES
ALLELE
SYNAPSIS
BIVALENT
(TETRAD)
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AP Biology
Sexual Reproduction and Inheritance
Reading Guide – Chapters 7.1, 7.4, 8.4
SOMATIC CELL
GAMETE
HAPLOID
DIPLOID
12.
Is the following cell haploid or diploid?
a. Somatic cell
b. Sperm
c. Egg
d. Bacterium
Provide an overview of events for the two phases of meiosis:
MEIOSIS I
MEIOSIS II
13.
Is the DNA replicated in between Meiosis I and Meiosis II?
14.
How many chromosomes do the daughter cells of meiosis contain as compared to the parental
cell?
15.
What are the two events that occur in meiosis I that do NOT occur in mitosis?
16.
Explain how each of the following events contributes to genetic variation:
CROSSING-OVER
INDEPENDENT ASSORTMENT
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FERTILIZATION
AP Biology
Sexual Reproduction and Inheritance
Reading Guide – Chapters 7.1, 7.4, 8.4
The Phases of Meiosis
17.
When does tetrad (bivalent) formation occur?
18.
When does cross-over occur?
19.
When do homologous pairs of chromosomes align?
20.
When do homologous chromosomes separate?
21.
What happens to homologous chromosomes in meiosis I?
22.
At the completion of meiosis I are the cells diploid (2n) or haploid (n)?
23.
When do sister chromatids separate?
24.
How many times must centrioles be replicated in animal cells during meiosis?
25.
How is meiosis II similar to mitosis?
26.
A cell that is about to divide has 22 chromosomes, how many chromatids does it have?
Meiosis vs. Mitosis
27.
List the fundamental differences between meiosis and mitosis:
MEIOSIS
MITOSIS
Page 4 of 7
AP Biology
Sexual Reproduction and Inheritance
Reading Guide – Chapters 7.1, 7.4, 8.4
28.
List the similarities between meiosis and mitosis:
MEIOSIS
MITOSIS
Errors in Meiosis
29.
What is a karyotype? What can a karyotype be used for?
30.
Define nondisjunction.
31.
Describe the two ways that nondisjunction may occur.
32.
If nondisjunction occurs during Meiosis I in an oocyte, diagram the ploidy of possible zygotes
following fertilization with normal sperm.
33.
If nondisjunction occurs during Meiosis II in an oocyte, diagram the ploidy of possible zygotes
following fertilization with normal sperm.
Page 5 of 7
AP Biology
Sexual Reproduction and Inheritance
Reading Guide – Chapters 7.1, 7.4, 8.4
34.
Review the terms: inversion, deletion, translocation from Section 9.3. These chromosomal
aberrations are generally the result of errors in cross-over or homologous chromosome pairings.
Section 8.4 – Genetics of Prokaryotes
1. Describe binary fission. Is this a sexual or asexual form of reproduction?
2. Does sexual reproduction occur in prokaryotes?
3. How can genetic variation be introduced in a prokaryote?
4. Describe conjugation in bacteria.
5. Additional ways bacteria may transfer or receive new genetic material are through the processes of
transformation and transduction. Look up each of these terms in your text and briefly descrbe
them.
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AP Biology
Sexual Reproduction and Inheritance
Reading Guide – Chapters 7.1, 7.4, 8.4
Listed below are descriptions and examples of the different types of recombination in bacteria. Classify
each type as:
A.
B.
C.
transformation
transduction
conjugation
__________ Bacteria assimilate genetic material from surroundings
__________ Bacteria take up DNA from environment
__________ Gene transfer from one bacterium to another via bacteriophage
__________ Direct transfer of genes between two bacteria temporarily joined by sex pili
__________ DNA is transferred from one bacterium to another by a virus
__________ A plasmid is exchange between two bacteria through a pilus
__________ Bacterial strains A and B are growing together in a colony that has been infected
with viruses. After a short period of time, a new strain of bacteria is detected that
is very similar to strain A but has a few characteristics of B.
__________ The conversion of live R strain Steptococcus pneumoniae into S strain when
heat-killed S strain is added to R strain
__________ E. coli bacteria take up plasmid using CaCl2 and heat shock.
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