Biology Pre Board Paper 1

Name the type of cell division that takes place in the zygote of an organism exhibiting haplontic life cycle.

Mention the unique flowering phenomenon exhibited by Strobilanthus kunthiana (neelakuranaji). 

Write the equation that helps in deriving the net primary productivity of an ecosystem.

Write the name of the organism that is referred to as the 'Terror of Bengal'.

Differentiate between male and female heterogamety.

When and where do chorionic villi appear in humans? State their function.

Write the types of sex-determination mechanisms the following crosses show. Give an example of each type

(ii) Female ZW with Male ZZ

Name and describe the technique that helps in separating the DNA fragments formed by the use of restriction endonuclease.

State the relation between gross and net primary productivity.

Name two hormones that are constituents of contraceptive pills. Why do they have high and effective contraceptive value ? Name a commonly prescribed non-steroidal oral pill.

(a) Why is human ABO blood group gene considered a good example of multiple alleles?

(b) Work out a cross up to F1 generation only, between a mother with blood group A (Homozygous) and the father with blood group B (Homozygous). Explain the pattern of inheritance exhibited.

A DNA segment has a total of 1000 nucleotides, out of which 240 of them are adenine containing nucleotides. How many pyrimidine bases this DNA segment possesses?

State the Hardy-Weinberg principle.

Enlist the steps involved in inbreeding of cattle. Suggest two disadvantages of this practice.

Choose any three microbes, from the following which are suited for organic farming which is in great demand these days for various reasons. Mention one application of each one chosen.

Mycorrhiza; Monascus; Anabaena; Rhizobium; Methanobacterium; Trichoderma.

Study the graph given below and answer the questions that follow:

(i) Write the status of food and space in the curves (a) and (b).

(ii) In the absence of predators, which one of the two curves would appropriately depict the prey population?

(iii) Time has been shown on X-axis and there is a parallel dotted line above it. Give the significance of this dotted line.

Many plant and animal species are on the verge of their extinction because of loss of forest land by indiscriminate use by the humans. As a biology student what method would you suggest along with its advantages that can protect such threatened species from getting extinct?

A large number of married couples the world over are childless. It is shocking to know that in India the female partner is often blamed for the couple being childless.
(a) Why in your opinion the female partner is often blamed for such situations in India ? Mention any two values that you as a biology student can promote to check this social evil.
(b) State any two reasons responsible for the cause of infertility.
(c) Suggest a technique that can help the couple to have a child where the problem is with the male partner.

How did Hershey and Chase established that DNA is transferred from virus to bacteria?

With advancements 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 a crop.