Plant Growth and Mineral Nutrition — BIOLOGY STD 12 Science — Question

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 foetal membrane that provides a fluid medium to the developing embryo. Mention its two functions.

Explain how and why controlled breeding experiment is carried out in cattle.
OR
Define artificial insemination. What are its advantages over conventional breeding?

Answer the following questions:
How do human males with ‘XXY’ abnormality suffer?

Give functions : Hybridization

Why do some plants have both chasmogamous and cleistogemous plants flowers?

1. It is generally observed that the children who had suffered from chicken - pox in their childhood may not contract the same disease in their adulthood. Explain giving reasons the basis of such an immunity in an individual. Name this kind of immunity.
2. What are interferons? Mention their role.

What are the various public health measures, which you would suggest as safeguard against infectious diseases?

1. Mature seeds of legumes are non-albuminous.Then, can it be considered that double fertilization does not occur in legumes? Explain your answer.
2. Write one similarity and one difference between autogamy and geitonogamy.

Transgenic animals are the animals in which a foreign gene is expressed. Such animals can be used to study the fundamental biological process, phenomenon as well as for producing products useful for mankind. Give one example for each type.