The Developing Human 10th Edition Moore Test Bank
Moore: The Developing Human, 10th Edition
Chapter 01: Gametogenesis and Fertilization
Test Bank
MULTIPLE CHOICE
Directions: Each group of questions below consists of a numbered list of descriptive words or phrases accompanied by a diagram with certain parts indicated by letters or by a list of lettered headings. For each numbered word or phrase, select the lettered part or heading that matches it correctly and then insert the letter in the space to the right of the appropriate number. Sometimes more than one numbered word or phrase may be correctly matched to the same lettered part or heading.
- Haploid nuclei that fuse to form a zygote
- Polar body
- Capacitation
- Acrosome
- Zona pellucida
- Pronuclei
ANS: 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.
- Changes occur in it that inhibit entry of sperm
- Polar body
- Capacitation
- Acrosome
- Zona pellucida
- Pronuclei
ANS: 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.
- Contains enzymes that digest a path for the sperm
- Polar body
- Capacitation
- Acrosome
- Zona pellucida
- Pronuclei 1 / 4
ANS: 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.Polar body
- A
- B
- C
- D
- E
ANS: 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
- B
- C
- D
- E
ANS: C
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. 2 / 4
6.Meiotic spindle
- A
- B
- C
- D
- E
ANS: 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
- A
- B
- C
- D
- E
ANS: A
The corona radiata consists of one or more layers of follicular cells that surround the zona pellucida, the polar body, and the secondary oocyte. The corona radiata is dispersed during fertilization by enzymes released from the acrosomes of the sperms that surround the oocyte.
8.Haploid cell
- A
- B 3 / 4
- C
- D
- E
ANS: D
The polar body is the labeled haploid cell formed during the first meiotic division of the oocyte.The sperm is also a haploid cell zygote.
9.Embryoblast
- A
- B
- C
- D
- E
ANS: B
The embryoblast (inner cell mass) is recognizable about 4 days after fertilization. It is derived from the central cells of the morula. The embryoblast gives rise to the embryo and some extraembryonic tissues.
10.Gives rise to part of the placenta
- A
- B
- C
- D
- E
ANS: D
The trophoblast gives rise to the embryonic part of the placenta; the other part is derived from the endometrium. When the trophoblast becomes lined by extraembryonic somatic mesoderm, the combined layers are called the chorion. The trophoblast forms no part of the embryo.
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