1. Sperm cannot fertilize an egg until they have undergone theprocess of _______________.

2. The _______________ of an egg undergo exocytosis to produce a slow block topolyspermy.

3. The outer cell mass of a blastocyst, concerned with anchoring andnourishing the embryo, is called the _______________.

4. Prior to implantation, a conceptus is nourished by _______________.

5. Any agent that causes anatomical birth defects is called a/an _______________.

6. Nondisjunction of the twenty-first chromosome causes _______________.

7. The greatest age attainable by human beings is called the _______________.

8. Some of the senescent changes of the skin, called _______________, are due toa person's lifelong exposure to sunlight.

9. One hypothesis on aging relates it to the progressive shorteningof the _______________ at the ends of the chromosomes every time cells divide.

10. The failure of two homologous chromsomes to separate from eachother at anaphase I is called _______________.

11. The fetus floats in _______________, composed in large part of its own urine.

12. In the seventh month of development, the fetus turns into ahead-down _______________ position.

13. Prior to birth, a shunt called the _______________ between theascending aorta and pulmonary trunk allows most blood to bypass the lungs.

14. The placenta is composed partly of maternal tissue and partly ofthe _______________, one of the four embryonic membranes.

15. Attachment of the blastocyst to the uterine wall is called _______________.

Copyright ©1998 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use and Privacy Policy.
McGraw-Hill Higher Education is one of the many fine businesses of The McGraw-Hill Companies.
For further information about this site contact mhhe_webmaster@mcgraw-hill.com.