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

Kanchan went to a garden and saw some flowers which were closed. She assumed that those flowers must be buds. But she was astonished to see that all the flowers of that plant were closed and none of them was open. She was confused and asked her queries to her teacher.

1. What do you think, are there any plants with closed flowers? Give an example.
2. Are such plants get pollinated? Explain.
3. What are such flowers/ plants called?
4. What values are shown by Kanchan?

Study the following diagram, and answer these questions:

1. Why does a wide arrow point from both producers and consumers to decomposers?
2. Why does a wide arrow point only from inorganic nutrient pool to producers?
3. Why don't the wavy arrows point from decomposers to producers?

What is productivity. What do you mean by net Primary productivity. Differentiate between primary productivity and secondary productivity.

What is mutation? Explain with the help of an example, how a point mutation does affect the genetic code. Name another type of mutation.

Explain enzyme-replacement therapy to treat adenosine deaminase deficiency. Mention two disadvantages of this procedure.

What is recombinant DNA? For creating recombinant vector molecule, can two different restriction enzymes be used for cutting vector and source DNA?

When do you describe the relationship between two organisms as mutualistic, competitive and parasitic? Give one example of each type.

The species diversity of plants (22 per cent) is much less than that of animals (72 per cent). What could be the explanations to how animals achieved greater diversification?

Differentiate between intraspecific and inter specific competition.