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Ch. 01: Gametogenesis and Fertilization
Test Bank Questions
CH.
1. ________ Haploid nuclei that fuse to form a zygote
a. Polar body
b. Capacitation
c. Acrosome
d. Zona pellucida
e. Pronuclei
ANSWER: E
The_ male and female pronuclei are the_ haploid nuclei of the_ sperm and oocyte,
respectively. They fuse during fertilization to form the_ diploid nucleus of a zygote.
The_ nucleus occupies most of the_ head of the_ sperm, and after it enters the_
oocyte, it swells to form the_ male pronucleus. The_ pronuclei are about equal in size
and show similar features.
2. ________ Changes occur in it that inhibit entry of sperm
a. Polar body
b. Capacitation
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c. Acrosome
d. Zona pellucida
e. Pronuclei
ANSWER: D
The_ zona pellucida undergoes changes, called the_ zona reaction, when a sperm
contacts the_ cell membrane of a secondary oocyte. These changes, caused by the_
release of substances from the_ oocyte, prevent other sperms from passing through
the_ zona pellucida and entering the_ oocyte.
3. ________ Contains enzymes that digest a path for the_ sperm
a. Polar body
b. Capacitation
c. Acrosome
d. Zona pellucida
e. Pronuclei
ANSWER: C
The_ acrosome is a caplike structure that invests the_ anterior half of the_ head of
the_ sperm. It contains enzymes that pass through perforations in its wall and digest a
path for the_ sperm to follow through the_ zona pellucida to fertilize the_ oocyte.
4.
2
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________ Polar body
a. A
b. B
c. C
d. D
e. E
ANSWER: D
The_ first polar body forms during the_ first meiotic division. Note that it is inside the_
zona pellucida with the_ secondary oocyte. Although it may divide into two polar
bodies, these cells degenerate. The_ secondary oocyte receives the_ same number of
chromosomes as the_ polar body; however, it gets almost all the_ cytoplasm.
5.
________ Zona pellucida
a. A
b. B
c. C
d. D
e. E
ANSWER: C
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The_ zona pellucida surrounds the_ secondary oocyte and the_ polar body. This
membrane is surrounded by a layer of follicular cells called the_ corona radiata. The_
zona pellucida appears homogeneous in the_ fresh condition, but under the_ electron
microscope it appears granular and shows some concentric layering.
6.
________ Meiotic spindle
a. A
b. B
c. C
d. D
e. E
ANSWER: E
Contact of a sperm with the_ cell membrane of the_ oocyte stimulates the_ secondary
oocyte to complete its second meiotic division. This contact also brings about the_
zona reaction, preventing entry of more sperms. The_ sperm penetrates the_ cell
membrane of the_ secondary oocyte and then passes into the_ cytoplasm of the_
oocyte, leaving its cell membrane outside the_ oocyte.
7.
________ Corona radiata
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Ch. 01: Gametogenesis and Fertilization
Test Bank Questions
CH.
1. ________ Haploid nuclei that fuse to form a zygote
a. Polar body
b. Capacitation
c. Acrosome
d. Zona pellucida
e. Pronuclei
ANSWER: E
The_ male and female pronuclei are the_ haploid nuclei of the_ sperm and oocyte,
respectively. They fuse during fertilization to form the_ diploid nucleus of a zygote.
The_ nucleus occupies most of the_ head of the_ sperm, and after it enters the_
oocyte, it swells to form the_ male pronucleus. The_ pronuclei are about equal in size
and show similar features.
2. ________ Changes occur in it that inhibit entry of sperm
a. Polar body
b. Capacitation
1
, Test bank
c. Acrosome
d. Zona pellucida
e. Pronuclei
ANSWER: D
The_ zona pellucida undergoes changes, called the_ zona reaction, when a sperm
contacts the_ cell membrane of a secondary oocyte. These changes, caused by the_
release of substances from the_ oocyte, prevent other sperms from passing through
the_ zona pellucida and entering the_ oocyte.
3. ________ Contains enzymes that digest a path for the_ sperm
a. Polar body
b. Capacitation
c. Acrosome
d. Zona pellucida
e. Pronuclei
ANSWER: C
The_ acrosome is a caplike structure that invests the_ anterior half of the_ head of
the_ sperm. It contains enzymes that pass through perforations in its wall and digest a
path for the_ sperm to follow through the_ zona pellucida to fertilize the_ oocyte.
4.
2
, Test bank
________ Polar body
a. A
b. B
c. C
d. D
e. E
ANSWER: D
The_ first polar body forms during the_ first meiotic division. Note that it is inside the_
zona pellucida with the_ secondary oocyte. Although it may divide into two polar
bodies, these cells degenerate. The_ secondary oocyte receives the_ same number of
chromosomes as the_ polar body; however, it gets almost all the_ cytoplasm.
5.
________ Zona pellucida
a. A
b. B
c. C
d. D
e. E
ANSWER: C
3
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The_ zona pellucida surrounds the_ secondary oocyte and the_ polar body. This
membrane is surrounded by a layer of follicular cells called the_ corona radiata. The_
zona pellucida appears homogeneous in the_ fresh condition, but under the_ electron
microscope it appears granular and shows some concentric layering.
6.
________ Meiotic spindle
a. A
b. B
c. C
d. D
e. E
ANSWER: E
Contact of a sperm with the_ cell membrane of the_ oocyte stimulates the_ secondary
oocyte to complete its second meiotic division. This contact also brings about the_
zona reaction, preventing entry of more sperms. The_ sperm penetrates the_ cell
membrane of the_ secondary oocyte and then passes into the_ cytoplasm of the_
oocyte, leaving its cell membrane outside the_ oocyte.
7.
________ Corona radiata
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