Biodiversity and Conservation — BIOLOGY STD 12 Science — Question

i. Write how parasites have evolved with adaptation to co-exist with their hosts in an ecosystem.
ii. Parasites are host specific and tend to co-evolve. How would the parasite respond if the host evolves a certain mechanism to resist or reject the parasite?

Where does fertilization take place in human female?

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

What is xenogamy. Explain in detail the various adaptations found in plants for xenogamy.

State the theory of Biogenesis. How does Miller’s experiment support this theory?

What type of organs eye of an Octopus and that of a human called? Give another example from the animal group and one from the plants of such organs. Name and explain the evolutionary process they exhibit.

There are many animals that have become extinct in the wild but continue to be maintained in Zoological parks.

1. What type of biodiversity conservation is observed in this case?
2. Explain any other two ways which help in this type of conservation.

In cattle, hornless (H) is dominant over horned (h) and black (B) is dominant over red (b). Consider that these two pairs of genes assort independently.

1. What proportion of the offspring from the cross, BbHh x bbhh, would be black and hornless?
2. From the cross Bbhh x Bbhh, how many will be:

1. Black and horned.
2. Red and horned.