Question Bank [2022] — BIOLOGY STD 12 Science — Question

Is there any relationship between dedifferentiation and the higher degree of success achieved in plant tissue culture experiments?

1. Write the desirable characters a farmer looks for in his sugarcane crop.
2. How did plant breeding techniques help north Indian farmers to develop cane with desired characters?

Indiscriminate human activities such as alien species invasion, fragmentation and habitat loss have accelerated the loss of biodiversity. Justify by taking one example for each.

Describe the structure of the heart wall.

Mohan, a class 8th student was reading a science chapter illustrating reproduction in animals, and showcasing how higher animals like elephant, cat, dog and even humans reproduce and increase their population. He asked his father about it.
His father explained the process of sexual reproduction to him and also appreciated him for his interest in the subject.

1. How do higher animals reproduce?
2. Do these animals reproduce throughout their life? Justify.
3. Write the values portrayed by Mohan.

1. Can a plant flowering in Mumbai be pollinated by pollen grains of the same species growing in New Delhi? Provide explanations to your answer.
2. Draw the diagram of a pistil where pollination has successfully occurred. Label the parts involved in reaching the male gametes to its desired destination.

Show with the help of a flow chart only, the life cycle of malerial parasite in humans.

short answer questions
What is colostrum?

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.

Explain xerarch succession highlighting the xeral communities.