HSC Science इयत्ता १२ - Tamil Nadu Board of Secondary Education Question Bank Solutions for Zoology

Explain the formation of a nucleosome.

A population will not exist in Hardly Weiberg equilibrium if ____________.

How does Hardy-Weinberg’s expression (p²+2pq+q²=1) explain that genetic equilibrium is maintained in a population? List any four factors that can disturb the genetic equilibrium.

Explain how mutations, natural selection and genetic drift affect Hardy Weinberg equilibrium.

Explain why cloning of Dolly, the sheep was such a major scientific breakthrough?

Mention the advantages and disadvantages of cloning.

Expand the following.

ICSI

Write notes on the following:

Eutrophication

How can we control eutrophication?

Correct the following statement

Transfer of an ovum collected from donor into the fallopian tube is called ZIFT.

Which method do you suggest the couple to have a baby, if the male partner fails to inseminate the female or due to very low sperm count in the ejaculate?

E. coli cell grown on ¹⁵N medium are transferred to ¹⁴N medium and allowed to grow for two generations. DNA extracted from these cells is ultracentrifuged in a cesium chloride density gradient. What density distribution of DNA would you expect in this experiment?

What is the basis for the difference in the synthesis of the leading and lagging strand of DNA molecules?

Which of the following statements about DNA replication is not correct?

Which of the following statements is not true about DNA replication in eukaryotes?

Meselson and Stahl’s experiment proved ______.

Differentiate between Leading stand and lagging strand.

From their examination of the structure of DNA, What did Watson and Crick infer about the probable mechanism of DNA replication, coding capability, and mutation?

a) Identify the figure given below

b) Redraw the structure as a replicating fork and label the parts

c) Write the source of energy for this replication and name the enzyme involved in this process.

d) Mention the differences in the synthesis of protein, based on the polarity of the two template strands.

Klinefelters’ syndrome is characterized by a karyotype of ____________.