NATIONAL OPEN UNIVERSITY OF NIGERIA BIO 413 DEVELOPMENTAL BIOLOGY
14-16 AHMADU BELLO WAY, VICTORIA ISLAND LAGOS SCHOOL OF SCIENCE AND TECHNOLOGY OCTOBER/NOVEMBER 2014 EXAMINATION
COURSE TITLE: DEVELOPMENTAL BIOLOGY
COURSE CODE: BIO 413
TIME ALLOWED: 2 HOURS
INSTRUCTION: ANSWER QUESTION 1 AND ANY OTHER THREE QUESTIONS
- a) Define the terms: meiosis, fertilization, gastrulation, differentiation and organogenesi (5marks)
- b) What are the three functions of Sertoli cells? (3 marks)
- c) What are the six fundamental questions considered by developmental scientists? (6 marks)
- d) Enumerate the various types of eggs based on the distribution and amount
of yolk (6 marks)
- e) Enumerate and describe four planes of cleavage, providing named examp (4 marks)
- f) Enumerate and describe the types of placenta in animals, based on
histology (4 marks), degree of association(3 marks) and distribution of villi
- g) State the germ layer that produces the 5 basic animal tissues.(5 marks)
- h) What is the fate of the primitive streak? (2 marks)
- 2. Compare and contrast mitosis and meiosis, indicating their roles in animal developmen (20 marks)
- 3. Using 2 named examples and illustrations describe the 5 essential stages and processes of ferti (15 marks)
What are the basic differences between external and internal fertilization?
- 4. a) With due consideration of the diverse animal symmetries (4 marks), the distribution (4 marks) and amount of yolk (2marks), elaborate on the different types and nature of cleavage.
- b) Describe the cleavage in amphibians (10 marks).
- 5. a) What are the basic features of gastrulation?(2marks). Elaborate, giving named examples with illustrations, five (5) types of cell movements during gastrulation (5×3= 15 marks).
- b) How is cleavage different from gastrulation? (3 marks)
- 6. Outline and describe the process of neurulation and brain forma (20 marks)