GENETICS (LSE-03)

ASSIGNMENT

2009

Dear Student,

As explained in the Programme Guide for B.Sc., you will have to do one assignment for the elective course in Genetics (LSE-03). The assignment is Tutor Marked Assignment (TMA) and is based on all the four blocks of the course.

The instructions for doing the assignment are provided in the Programme Guide under Section 7.1 “Assignment”. Do read the instructions carefully before starting your work.

Please note that:

(i)This assignment is valid from January 01, 2009 to December 31, 2009

(ii)However, we strongly suggest that you should send your response to this assignment, to the Study Centre Coordinator within fourteen weeks of the receipt of this booklet in order to get the feedback and comments on the evaluated assignment,

(iii)However, in any case, you have to submit the assignment response before appearing in the term end examination.

We strongly suggest that you retain a copy of your assignment.

Wishing you all good luck.

ASSIGNMENT

Course Code: LSE-03

Assignment Code : LSE-03/2009

Max. Marks : 100

  1. Describe with a suitable cross Mendel’s Law of Independent Assortment. 5
  2. Briefly explain the five types of chromosomal sex determination mechanisms

citing one example of each. 10

  1. Discuss the concept of genetic linkage and differentiate between complete and

incomplete linkage. 5

  1. Distinguish between dominant and recessive epistasis giving one example of

each. 5

  1. A double heterozygote AaBb is test-crossed. This resulted in the following

progeny types:

AaBb = 40, aabb = 40, Aabb = 10, aaBb = 10.

Interpret these results. 5

  1. Explain uniparental inheritance with a suitable example. 5
  2. With the help of clear and labelled diagrams describe the four types of structural

abnormalities that occur in chromosomes.10

  1. Make a distinction between autopolyploidy and allopolyploidy. Explain their role

in plant breeding by giving suitable examples. 5

  1. Describe the continuous and discontinuous phenotypic variations and give one

example for each of these categories. 5

  1. Detail the three mechanisms of gene transfer in bacteria. 6
  2. Explain the role of Major Histocompatibility Complex (MHC) in the mammalian

immune system. 4

  1. Elucidate the different control points of gene expression in organisms. What is

the most prevalent mode of control of gene expression in prokaryotes? 10

  1. Mention any two examples of oncogenic viruses. Make a flow-chart to show the

steps involved in cellular transformation by a RNA tumor virus. 10

  1. How is the Ti plasmid of Agrobacterium tumefaciens used in plant genetic engineering?

Give the process involved in detail. 5

  1. State the Hardy-Weinberg Law enlisting the conditions under which it is applicable. 5
  2. What is genetic counselling? How is the parental diagnosis of genetic disorders

helpful in the improvement of human health? 5