Sexual Reproduction in Flowering Plants — BIOLOGY STD 12 Science — Question

The following graph shows the species-area relationship. Answer the following question as directed.

1. Name the naturalist who studied the kind of relationship shown in the graph. Write the observation made by him.
2. Write the situations as discovered by the ecologists when the value of 'Z' (slope of the line) lies.

1. 0.1 and 0.2
2. 0.6 and 1.2

What does 'Z' stand for?

3. When would the slope of the line 'b' become steeper?

‘Fertilisation is not an obligatory event for fruit production in certain plants’. Explain the statement.

Discuss the production of wheat and rice varieties during green revolution.

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

How can we improve the success rate of fertilisation during artificial insemination in animal husbandry programmes?

1. Draw a diagram of pistil showing pollen tube growth in angiosperm and label;

1. Stigma.
2. Male gametes.
3. Micropyle.
4. Ovule.

2. Write the function of micropyle.

This image highlights the process of Gene Therapy of ADA-SCID.

i. Mention the cause of ADA deficiency in humans.
ii. How has genetic engineering helped patients suffering from it?

If your family owned a dairy farm, what measures would you undertake to improve the quality and quantity of milk production?

Explain, how Eli Lilly, an American company produced insulin by recombinant DNA technology.
OR
Explain how the company, Eli Lilly was able to produce human insulin using recombinant DNA technology.

Water pollinated (hydrophilous) plants.