Biotechnology: Principles and Processes — BIOLOGY STD 12 Science — Question

Monocistronic structural genes in eukaryotes have interrupted coding sequences. Explain. How are they different in prokaryotes?

A person has to perform crosses for the purpose of studying inheritance of a few traits/ characters. What should be the criteria for selecting the organisms?

Draw a schematic transverse section of a mature anther of an angiosperm. Label its epidermis, middle layers, tapetum, endothecium, sporogenous tissue and the connective.

To which category of cells do B-cells and T-cells belong? How do they differ from each other with reference to their formation and response to antigens?

A team of students are preparing to participate in the interschool sports meet. During a practice session you find some vials with labels of certain cannabinoids.

1. Will you report to the authorities? Why?
2. Name a plant from which such chemicals are obtained.
3. Write the effect of these chemicals on human body.

Name the polymerase which is generally used in PCR? What is the source of this enzyme?

A farmer harvests his crop and expresses his harvest in three different ways.

1. I have harvested 10 quintals of wheat.
2. I have harvested 10 quintals of wheat today in one acre of land.
3. I have harvested 10 quintals of wheat in one acre of land, 6 months after sowing.

Do the above statements mean one and the same thing. If your answer is yes, give reasons. And if your answer is ‘no’ explain the meaning of each expression.

Answer the following questions:
Explain sex determination in humans.

Identify the figure given alongside.

What is gene therapy? Illustrate using the example of adenosine deaminase (ADA) deficiency.