Biodiversity and Conservation — BIOLOGY STD 12 Science — Question

Rearrange the following in the correct sequence to accomplish an important biotechnological reaction:

1. In vitro synthesis of copies of DNA of interest,
2. Chemically synthesised oligonucleotides,
3. Enzyme DNA-polymerase,
4. Complementry region of DNA,
5. Genomic DNA template,
6. Nucleotides provided,
7. Primers,
8. Thermostable DNA-polymers (From Thermus aquaticus),
9. Denaturation of dsDNA.

Bee keeping practice is a good income generating industry. Write the different points to be kept in mind for successful bee keeping. Write the scientific name of the most common Indian species used for the purpose.

Answer the following questions:
List any four characteristics of an ideal contraceptive.

What is a carcinogen? Name one chemical carcinogen with its target tissue.

What are the different characters that develop due to Klinefelter's syndrome?

The cytological observations made in a number of insects led to the development of the concept of genetic/ chromosomal basis of sex-determination mechanism. Honey bee is an interesting example to study the mechanism of sex-determination. Study the schematic cross between the male and the female honey bees given below and answer the questions that follow:

1. Identify the cell divisions ‘A’ and ‘B’ that lead to gamete formation in female and male honey bees respectively.
2. Name the process ‘C’ that leads to the development of male honey bee (drone).

Does this CSF remain enclosed inside the ventricles? What can be the outcome of such a situation?

An organic farmer relies on natural predation for controlling plant pests and diseases. Justify giving reasons why this is considered to be a holistic approach.

Explain incomplete dominance with suitable example.

1. Write two differences between Homo erectus and Homo habilis.
2. Rearrange the following from early to late geologic periods:

Carboniferous, Silurian, Jurassic.