Reproduction in Lower and Higher Animals — BIOLOGY STD 12 Science — Question

What are vegetative propagules? Name any four of them along with an example for each.

Explain how Hershey – Chase experimentally proved that DNA is the genetic material.

Looking at the deteriorating air quality because of air pollution in many cities of the country, the citizens are very much worried and concerned about their health. The doctors have declared health emergency in the cities where the air quality is very severely poor.

1. Mention any two major causes of air pollution.
2. Write any two harmful effects of air pollution to plants and humans.
3. As a captain of your school Eco-club, suggest any two programmes you would plan to organise in the school so as to bring awareness among the students on how to check air pollution in and around the school.

Explain the mechanism of sex determination in case of birds.

Try to trace the various components of human evolution (hint: brain size and function, skeletal structure, dietary preference, etc.)

Does apiculture offer multiple advantages to farmers? List its advantages if it is located near a place of commercial flower cultivation.

Hydrophily.

Disorders of adrenal cortical hormones.

1. A mere 0.1 percent impurities make domestic sewage unfit for human consumption. Categorise the types of impurities with one example each.
2. What is polyblend?
3. Why does a greenhouse warm up?

Describe the events of spermatogenesis with the help of a schematic representation.