Biodiversity and Conservation — BIOLOGY STD 12 Science — Question

On a visit to a Hill station, one of your friend suddenly become unwell and felt uneasy.

1. List two symptoms you would look for to term it to be due to allergy.
2. Explain the response of the body to an allergen.
3. Name two drugs that can be recommended for immediate relief.

Differentiate between divergent and convergent evolution. Give one example of each.

Explain as to how protection of biodiversity hot spots alone can reduce up to 30% of the current rate of species extinction.

What are 'cry-proteins'? Explain with the help of a suitable example how it works as a biopesticide.

In relation to energy transfer in ecosystem, explain the statement "10kg of deer's meat is equivalent to 1kg of lion's flesh".

Describe Structure of typical angiospermic seed.

 In which phase of menstrual cycle is corpus luteum formed?

Name the place in human ovary where the first meiotic division is completed during oogenesis. What are the products of this division? Give the chromosome number of each type of cells involved in the process.

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).

Write any four differences between Vasa efferentia and Vasa deferentia.