Chapter 29 Development
1. What percentage of sperm cells introduced into the vagina normally reach the oocyte?
Less than 1 percent (200 out of 200,000,000)

2.The term syngamy refers to the
Fusion of sperm with a secondary oocyte; chemical changes prevent a second sperm from entering the oocyte

3.How many days after fertilization does implantation of the blastocyst occur?
6 days on average

4. At day 4 after fertilization, the solid ball of cells that has formed is called the
Morula

5. Implantation usually occurs in the
Fundus and posterior wall of uterus

6. The enzymes that allow implantation to occur are produced by the
Synchtiotrophob last

7. The human gestation period is about
36-38 weeks

8. The chorion develops from the
Trophoblast

9. The embryonic disc develops from the
Inner cell mass

10. The embryonic period of development covers what time period?
Fertilization to the 8th week

11. For fertilization to occur, a sperm must penetrate
Into the corona radiate---> zona pellucida (zp3)---> cell membrane

12. The amnion forms from the
Cytotrophoblast

13. The yolk sac forms from the
Endoderm of inner cell mass

14. The extraembryonic coelom becomes the
Ventral body cavity (thoracic and ab cavity)

15. The “water” referred to when a woman's “water breaks” prior to delivery is
Amniotic fluid

16. The endometrium is digested by enzymes released from the
Synctiotrophob

17. Exchange of gases, nutrients, and wastes between maternal and fetal blood takes place between the
Decidua basalis of the uterus and chronic villi

18. The portion of the endometrium that covers the embryo and is located between the embryo and the uterine cavity is the
Decidua capsularis

19. Most materials cross the placenta by
Diffusion

20. Deoxygenated fetal blood is carried to the placenta via the
Two umbilical arteries

21. The reason the corpus luteum is maintained in early pregnancy is to
To maintain the uterus lining by hcG which functions as FSH & LH

22. Human chorionic gonadotropin is produced by the
Trophoblast cells of the corian

23. During early pregnancy, the main function of hCG is to
Maintain the corpus luteum for first 3 months

24. Human chorionic gonadotropin is at its highest levels during
9th week of pregnancy (almost 3 months)

25. Once hCG levels decrease, estrogen and progesterone are secreted mainly by the
Placenta, on 4th month

26. Peak secretion of hCS occurs
Late in the 3rd trimester (8-9 months)

27. Early pregnancy tests are based on detection of what substance in the urine?
HCG

28. The observable characteristics of a person's genetic makeup are known as the
Phenotype

29. An individual whose alleles for a particular trait are the same is said to be
Homozygous

30. The two alternative forms of a gene that code for the same trait and are at the same locus on homologous chromosomes are called
Alleles

31. A person is heterozygous for a particular trait if he/she has
Different alleles on homologous chromosomes; one dominant allele and one recessive allele

32. If a person's phenotype is intermediate between homozygous dominant and homozygous recessive then inheritance of this trait is an example of
Incomplete dominance

33. Most pregnancy tests are based on the presence or absence of
HCG

34. What would be the possible blood phenotypes of the offspring of parents who are genotype II and IA I B?
50% type A and 50% type B

35. Inheritance of the ABO blood type is an example of
Codominance

36. How many pairs of autosomes does a normal human have?
22 pairs

37. A child expresses an autosomal recessive trait. Which of the following are possible genotypes for the parents?
Both parents must carry the recessive gene as carrier or carry the disease. Ex: abinism father: Pp mother: Pp