No. of Printed Pages: 8 ILSE-OSI
BACHELOR OF SCIENCE (B.Sc.)
Term-End Examination
June, 2016

U1455
LIFE SCIENCE
LSE-03 GENETICS

Time hours Maximum Marks: 50
Note: Question no. 1 is compulsory. Attempt any four questions from questions no. 2 to 7.

1. Fill in the blanks in any four of the following: 4x1=4

Mendel proposed the concept of units.

The credit for the chromosome theory of inheritance goes to Walter Sutton and .

DNA is the store-house of information.

In 1950, Ruth Sager isolated a of Chlamydomonas Reinhardtii which cannot grow in the presence of the antibiotic Streptomycin.

A bacteriophage is a parasite.

Write suitable terms for any four of the following: 4x1=4

All chromosomes other than sex chromosomes

A chemical that prevents formation of spindle during nuclear division

Genetically identical cells or organisms devised from a single ancestor by asexual or parasexual method

A complete set of chromosomes (hence, of genes) inherited as a unit from one parent

The development of new individual from an egg without fertilisation

Match the items given under Column A and Column B correctly and rewrite them:

ColumnA ColumnB

Agglutination Extra chromosomal circular DNA molecule

Prophage A tumourous growth in plants

Episome Aggregation of antigen by antibody

Gall Phage genome integrated in a bacterium

2. Write short notes on any four of the following: 4x2 1/2 =10

Sex reversal

Mitochondrial DNA

Turner Syndrome

Physical mutagens

Method of studying geotaxis in Drosophila

3. Give an example of a prokaryote and explain how sexual reproduction occurs in it. 5

Discuss the effect of environmental factors in the development of a particular sex type in worms and reptiles. 5

4. What is induced polyploidy Explain two applications of polyploidy. 5+5=10

5. With the help of a clear and labelled diagram describe the components of lac operon. 10

6. What are the various components of genetic counselling? Explain how it helps an individual or a family:' 5+5=10

7. Write accounts of any two of the following: 5+5=10

Sex mosaic

Inversions in chromosomes

Hormonal regulation of transcription

Alcohol preference in mice as an example to study behavioural genetics