The following statements (i),(ii) and (iii) seem to describe the water-pollination submerged plants. Which one of these statements is incorrect?
(i) The flowers do not produce nectar.
(ii) The pollen grains have mucilaginous covering.
(iii) The brightly-coloured female flowers have long stalks to reach the surface.

1

(a)

(iii) is incorrect.

Comment on the RCH programme of the government to improve the reproductive health of the people.

1

(a)

Creating public awareness regarding reproduction related aspects and providing facilities to build up a healthy society with added emphasis on the health of mother and child are the basic aims of the RCH programmes.

What is recombination?

1

(a)

What is the term used for the regions of a gene which become part of mRNA and code for the different regions of proteins?

1

(a)

Exons

In a certain population, the frequency of three genotypes is as follows:

Genotypes	BB	Bb	bb
Frequency	22%	62%	16%

what is the likely frequency of alleles B and b?

1

(a)

Frequency of allele B=22(BB)+1/2\(\times\)62(Bb) =22+31=53% 
Frequency of allele b=1/2\(\times \)62(bB)+16(BB)  =31+16=47%                                            

Why is secondary immune response more intense than the primary immune response in human?

1

(a)

It is because human body appears to have more memory of first encounter.

A person who is allergic to pulses is advised to take a capsule of spirulina daily.Give the reason for the advice.

1

(a)

It does not induce any immunological responce

What would happen if our intestine harbors microbial flora exactly similar to that found in the rumen of cattle?

1

(a)

Microbial flora present in the rumen of cattle takes part in digestion of cellulose. Presence of this microbial flora will enable us to digest cellulose.

What is a plasmid?

1

(a)

Plasmid is a small, double strended, closed circular, symbiotic DNA molecule that ocurs naturally in bacteria, outside the bacterial chromosome.

Suggest a technique to a researcher who need to separate fragments of DNA.

1

(a)

Gel Electrophoresis

Why are green plants not found beyond a certain depth in the ocean?

1

(a)

Green algae or plants are not found beyond a certain depth, as light (not all colour components of visible spectrum) is not available

Why are oceans least productive?

1

(a)

(i) Deficiency of nutrients like nitrogen.
(ii) Reduced availability of light in deeper layers of water.

When was Ramsar convention on Biological diversity held in Rio de Janeiro known as?

1

(a)

It was developed in 1971 and came into force from December, 1975.

Justify the statement "Vegetative reproduction is also a type of asexual reproduction."

2

(a)

Why is the process of fertilisation in a flowering plant referred to as double fertilisation ? Explain.

2

(a)

How do injections and implants help in contraception?

2

(a)

Haemophilia is a sex-linked inheritance conditions in humans where a simple cut causes non-stop bleeding. Study the pedigree chart showing the inheritance of haemophilia in a family. Give reasons, which explain that haemophilia is (i) sex-linked, (ii) caused by X-linked gene.

2

(a)

Write a note on Typhoid.

2

(a)

How is a disease-resistant plant selected for successful breeding?

2

(a)

Find out from internet what is Golden Rice?

2

(a)

What is the difference between climate and weather?

2

(a)

Make a list of impurities present in domestic sewage.

2

(a)

Explain the events in a normal woman during her menstrual cycle on the following days:
(a) Ovarian event from 13-15 days
(b) Ovarian hormones level from 16 to 23 days
(c) Uterine events from 24 to 29 days

3

(a)

Explain the sex determination mechanism in humans.How is it different from birds?

3

(a)

What did background information Watson and crick had with them for developing a model of DNA? What was their own contribute

3

(a)

'How does the process of natural selection' affect Hardy-Weinberg equilibrium? List the other four factors that disturb the equilibrium.

3

(a)

1. Explain with  the help of a diagram the development of a mature embryo sac from a megaspore mother cell in angiosperm.

   5

   (a)

2. What are the characteristics of sex-linked inheritance?

   5

   (a)

1. What is a biogeographic map? Locate Galapagos Islands in the world atlas. What was unique about these islands which helped Darwin arrive at significant concepts regarding evolution?

   5

   (a)

2. With advancement in genetics, molecular biology and tissue culture, new traits have been incorporated into crop plants. Explain the main steps in breeding a new genetic variety of crop.

   5

   (a)

1. As we know, our rivers Ganga and Yamuna are getting polluted day-by-day.
   Many factories discharge sewage effluents into these rivers. The load of pollution in these rivers also increases due to municipal sewage and many things thrown by people in the name of worship. The government has however taken some steps to save these rivers.
   (i) What are the values shown by people who throw wastes in rivers?
   (ii) How could we help in decreasing pollution of rivers?
   (iii) State some advantages of saving the river.
   (iv) State the action taken by the government to stop the pollution in these rivers.

   5

   (a)

2. Can you list 10 recombinant proteins which are used in medical practice. Find out where they are used as therapeutics (use the internet).

   5

   (a)

1. List the major ecosystems (biomes) of the world.

   5

   (a)

2. What is environmental pollution? Can it occur without human intervention? Explain

   5

   (a)