Plant Water Relation — BIOLOGY STD 12 Science — Question

Ectomycorrhizae and Endomycorrhizae.

Rohan and his friends emptied all the overhead tanks, which were not in use for last few months. Some people did not like this. Rohan and his friends explained and convinced them about the hygienic benefits of their act.

1. What was the objective behind their act?
2. Explain in brief the stages of life cycle of a malarial parasite in human body.
3. Which pathogen is responsible for malaria?
4. What values did Rahul and his friends promote?

Describe the functions of the following:
Vagina.

Study the graph given below and answer the questions that follow:
Identify the ovarian phases during a menstrual cycle:

1. 5th day to 12th day of the cycle.
2. 14th day of the cycle.
3. 16th day to 25th day of the cycle.

Name the law that states that the sum of allelic frequencies in a population remains constant. What are the five factors that influence these values?

Blood clotting/Coagulation of blood.###Explain blood clotting in short.

A true breeding pea plant homozygous for axial violet flowers is crossed with another pea plant with terminal white flowers (aavv).
List the Mendel’s generalisations that can be derived from the above cross.

What is growth? What are its characteristics ?

Distinguish between : Diffusion and Osmosis.

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.

1. 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.
2. State any two reasons responsible for the cause of infertility.
3. Suggest a technique that can help the couple to have a child where the problem is with the male partner.