CS MAINS 2014 BOTANY Paper II

SECTION A

Q1. Giving reasons explain the following,:10x5=50

In what way does Mendel's law of inheritance (dominance) differ from incomplete dominance? 10

Selection of cytoplasmic-genetic male sterility in the development of hybrid varieties 10

Use of FISH technique in tracking the target organisms 10

Application of radiomimetic chemicals 10

Tests of significance in biology 10

Q2. Why do chromosomal aberrations happen 15

What are molecular probes? Mention their applications in biology. 15

How would you develop improved variety of basmati rice for organic farming conditions? . 20

Q3. When the glucose-grown cells of Coli' are transferred to the medium' containing lactose, what will be the fate of 'Lac Operon'? . 15

What do you understand by the 'cell cycle' Mention the important proteins that control the cell cycle. 20

What makes the ribosomal RNA gene (rRNA) suitable for phylogenetic studies? 15

Q4. Bnefly describe the various ty'pes of chromosomal aberrations.20
Give .an experimental evidence to. demonstrate that DNA is the genetic material. 15

Describe in detail the structure and chemical composition of ribosomes. 15

SECTIONB

Q5. Explain the following:

Apical dominance

IUCN classification of extinction risks

Biological species concept

Zinc deficiency in crop plants

Mechanism of drought resistance
10x5=50

Q6. What is seed germination? Define normal and abnormal seedlings. 15

Describe the roles played by mesophyll cells and bundle sheath cells in C4 pathway ofCO2 fixation. 20

Define 'biodiversity' and discuss the to conserve it. 15

Q7. Describe the role of national and international organisations established ,for germplasm conservation. 20

Explain: how proton-motive force drives t.he synthesis ofATP. 15

Give a brief note on the concept of sustainable development. 15

Q8. Explain how air and water pollution affect the agro-ecosystems. 20

What are 'symplasmids' Mention their role in root nodulation and N2'-fixation in the leguminous plants. 15

Does the process of nitrification synthesize ATP, and how is this energy conserved 15