National Open University Exam Past Question – BIO 413 OCTOBER/NOVEMBER 2014 EXAMINATION

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

1.

1. a) Define the terms: meiosis, fertilization, gastrulation, differentiation and organogenesi (5marks)
2. b) What are the three functions of Sertoli cells? (3 marks)
3. c) What are the six fundamental questions considered by developmental scientists? (6 marks)
4. d) Enumerate the various types of eggs based on the distribution and amount

of yolk (6 marks)

1. e) Enumerate and describe four planes of cleavage, providing named examp (4 marks)
2. f) Enumerate and describe the types of placenta in animals, based on

histology (4 marks), degree of association(3 marks) and distribution of villi

(2 marks)

1. g) State the germ layer that produces the 5 basic animal tissues.(5 marks)
2. h) What is the fate of the primitive streak?  (2 marks)

2. 2. Compare and contrast mitosis and meiosis, indicating their roles in animal developmen  (20 marks)

3. 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?

(5 marks)

4. 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.
5. b) Describe the cleavage in amphibians (10 marks).

5. 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).
6. b) How is cleavage different from gastrulation? (3 marks)

6. 6. Outline and describe the process of neurulation and brain forma (20 marks)