Evolution — BIOLOGY STD 12 Science — Question

During an excursion to a botanical garden, the teacher shows an old tree, which was on the verge of extinction. As soon as the teacher advanced with the students, some enthusiastic students climbed up the tree and started cutting the branches, collecting its leaves as precious collection. Rajesh instead took photographs of the tree from various angles. The boys mocked at Rajesh while the teacher appreciated him.

1. How can biodiversity be conserved?
2. What international initiatives were taken to conserve biodiversity?
3. What values did Rajesh possess?

Who propounded the Central Dogma principle and what is meant by it?

Discuss the significance of heavy isotope of nitrogen in the messelson and Stahl's experiment.

Among the ecosystem services are control of floods and soil erosion. How is this achieved by the biotic components of the ecosystem?

How is DNA recombinant technology helpful in detecting the presence of mutated genes in the cancer patients?

Explain that adolescence is a very sensitive phase of a person's mental and scientific development.

1. Write your observations on the variations seen in the Darwin’s finches shown above.
2. How did Darwin explain the existence of different varieties of finches on Galapagos Islands?

Briefly explain IVF and ET What are the conditions in which these methods are advised?

Write about positive agent transmission method incubation period symptoms prophylaxis and treatment of syphilis disease.

AtRNA is charged with the amino acid methionine.

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