Ecosystems — BIOLOGY STD 12 Science — Question

What is immunity? Name its types.

Nikhil goes with his family for dinner and insists on sitting in the non-smoking area to which his father (who is a heavy smoker) obiects.

How were complex organic molecules formed during chemical evolution?

The following graph represents the organismic response to certain environmental condition (e.g., temperature):

1. Which one of these, ‘a’ or ‘b’, depicts conformers?
2. What does the other line graph depict?
3. How do these organisms differ from each other with reference to homoeostasis?
4. Mention the category to which humans belong.

1. A tRNA is charged with the amino acid methionine.

1. Name the process involved in the attachment.
2. Point out the mRNA codon and anticodon on RNA for this amino acid.

2. What is heterochromatin?

How are alleles of particular gene differ from each other? Explain its significance.

List in proper sequence the processes involved in recombinant DNA (rDNA) technology.

1. In a human genome, which one of the chromosomes has the most genes and which one has the fewest?
2. Scientists have identified about 1.4 million single nucleotide polymorphs in human genome. How is the information of their existence going to help the scientists?

In an aquarium two herbivorous species of fish are living together and feeding on phytoplanktons. As per the Gause’s Principle, one of the species is to be eliminated in due course of time, but both are surviving well in the aquarium. Give possible reasons.

1. Expand VNTR and describe its role in DNA fingerprinting.
2. List any two applications of DNA fingerprinting technique.