SECTION A
1. The correct statement about gametes is:
a) The Spermatozoa can survive up to 72 hours
b) The oocyte can survive up to 48 hours
c) The result of fertilization is restoration of the haploid number of chromosomes
d) The unfertilized secondary cocyte normally degenerates within 4-8 hours
2. The correct statement about sperm capacitation is
a) It takes about 24 hours
b) The glycoprotein coat decapacitation factor is removed from the plasma membrane over the acrosome
c) Testosterone is a strong capacitating agent
d) It occurs in the epididymis
3. The incorrect statement about zona reaction is
a) It occurs after penetration of the corona radiata
b) The enzyme from the cortical granules alter sperm receptor molecules in the zona pellucida
c) It prevents polyspermy
d) renders other sperms incapable of fertilizing
4. The following are derived from the primitive fore gut except:
a) larynx
b) stomach
c) colon
d) trachea.
5. The following are true of an omphalocele
a) Coils of intestines herniated through the anterior abdominal wall
b) The umbilicus is attached separate to the ompalocele
c) The intestines are not covered by skin
d) Coils of the intestine herniated through the umbilicus
6. Which of these is most important during implantation
a) Cytotrophoblast
b) Syncytritrophoblast
c) Zona pelluciden
d) Corona radiate
7. The primitive streak is associated with the development of
a) Notochord
b) Mesoderm
c) Neuraltube
d) Epiblast.
8. The physiological hearniation of the intestines occurs during :
a) 4th week
b) 10th week
c) 8th week
d) 6th week
9. In Turners syndrome
a) Phenotype is male
b) Neck is webbed
c) There is normal mental development
d) They have slanting eyes
10. The following are excretory organs identified in an early embryo except:
a) Metanephros
b) Ureteric buds
c) Pronephros
d) Mesonephros
11. The point in meiosis where sister chromatids separate from each other is
a) metaphase 1
b) anaphase 1
c) anaphase 11
d) telophase
12. Follicle stimulating hormone
a) stimulates endometrial development
b) stimulates development of ovarian follicles
c) stimulates formation of corpus luteum
d) Stimulates spermatozoa to fertilize the ovum
13. The correct statement about oogenesis is;
a) 1st meiosis is arrested during metaphase by oocyte maturation inhibitor (OMI)
b) Resumption of meiosis and ovulation are by an ovulatatory stage in levels of oestrogen
c) Second meiosis is arrested at metaphase and completed after ovulation
d) The polar bodies serve to take the other half of the chromosomes
14. Implantation occurs in the stage of
a) Cleavage
b) Blastular
c) Gastular
d) Neurular
15. Which is the correct order of events during human development
a) Gametogenesis, fertilization, cleavage, morulla
b) Fertilization, gametogenesis, cleavage, morulla
c) Gametogenesis, cleavage, fertilization, morulla
d) Morulla, cleavage, fertilization,gametogenesis
16. The correct statement about the development of the notochord is
a) The ventral wall of the notochord process fuses with the underlying ectoderm in a caudo cranial direction
b) There is transient communication between the amniotic cavity and the yolksac called the notochordal canal
c) The notochordal process transforms into the notochordal plate
d) The margins of the notochordal plate fuse to form the notochordal process
17. In development of limbs which is the correct statement
a) The apical ectodermal ridge is the prime mover in the initial stage
b) The mesenchymal core is the prime mover in the later stages
c) There is epithelio-mesenchymal interaction
d) There is no programmed cell death
18. Syndactyle is characterized by
a) presence of an extra digit
b) two or more webbed digits
c) sole of foot twisted
d) incompletely formed digits
19. The following is the function of the placenta
a) Production of enzymes
b) Diffusion of nutrients and oxygen
c) Provides buoyancy to the embryo
d) Acts as a shock absorber.
20. Tetrallogy of Fallot consist of the following conditions except
a) Pulmonary stenosis
b) Ventral septal defect
c) Hypertrophy of right ventricle
d) Patent ductus arteriosus
SECTION B
1. Draw a well labeled diagram of a mature spermatozoa (5Marks)
2. Explain the defect and signs of Klinefelter’s syndrome (6 Marks)
3. Define fertilization and state the results of fertilization (7 Marks)
4. State six malformations of the limb ( 6marks)
5. Discuss the germ layers and the respective derivatives from each layer ( 8 marks)
6. Discuss the twinning process and the various types of twins (8marks)
SECTION C
1. (a) Explain factors that determine the effect of a teratogen(principles of teratogenicity) (5marks)
(b) Explain various forms of teratogens and their effects (15marks)
2. Describe the development of the midgut of the digestive system (15 marks)
b) Explain various malformations that can occur in this system(midgut) (5marks)
