Evolution — BIOLOGY STD 12 Science — Question

Raj was a known sportsman in his school. While returning home he found some unknown miscreants beating a young fellow. He tried to drive them off, but by that time the fellow died of injury. The police arrested Raj and he was put on trial. The judge being convinced by Raj's plea, ordered for DNA fingerprinting reports.

1. What is the basis of DNA fingerprinting?
2. Explain the steps in DNA fingerprinting.
3. Write the applications of DNA fingerprinting.
4. Raj's fingerprints on the dead body were sufficient to convict him but the judge asked for authentic proof. What values can be observed by the judge?

Describe the process of decomposition of detritus under the following heads: Fragmentation; leaching; catabolism; humification andmineralisation.

One chromosome contains one molecule of DNA. In eukaryotes the length of the DNA molecule is enormously large. Explain how such a long molecule fits into the tiny chromosomes seen at metaphase.

Study the figure of vector pBR322 given below in which foreign DNA is ligated at the Bam HI site of tetracyline resistance gene.

Answer the following questions:
i. Mention the function of rop.
ii. What will be the selectable marker for this recombinant plasmid and why?
iii. Explain transformation.

Suggest and describe a technique to obtain multiple copies of a gene of interest in vitro.

1. Write an equation for Verhaulst-Pearl Logistic Growth, where.

N - Population density at a timet E.

r - Intrinsic rate of natural increase.

K - Carrying Capacity.

2. Draw a graph for a population whose population density has reached the carrying capacity.
3. Why is this logistic growth model considered a more realistic one for most animal populations?
4. Draw a growth curve where resources are not limiting to growth of a population.

1. Differentiate between: Autogamy, Geitonogamy and Xenogamy.
2. Explain the events that occur during pollen-pistil interaction.

State the similarity and differences between geitonogamy and xenogamy. Why do cleistogamous flowers assure seed sets?

Ramesh is a small scale farmer and holds 2.5 acres of land. He would like to increase the yield in his farm. Rahul, a student of MSc. (Agriculture) advised him to go to the agricultural department centre of his locality to get biofertilisers according to the variety of the crop. He also suggested Ramesh to stop the use of chemical fertilisers.

1. Explain the term biofertilisers.
2. Name the biofertiliser that is used mostly in paddy fields.
3. What are the values shown by Rahul?

Represent schematically the life cycle of a malarial parasite.