Reproduction in Lower and Higher Animals — BIOLOGY STD 12 Science — Question

A person has been diagnosed to be HIV positive.

1. Name the test which the person underwent.
2. Write the full name of the pathogen involved and describe its structure.
3. Which particular cells of this person are likely to get destroyed?

Both Down’s syndrome and Turner’s syndrome are examples of chromosomal disorders. Cite the differences between the two.

Explain any three important characteristics of population.

What are the advantages of the techniques of GM crops?

Given below are the sequences of nucleotides in a particular mRNA and amino acids coded by it.
UUU AUG UUC GAG UUA GUG UAA
Phe - Met - Phe - Glu - Leu – Val
Write the properties of genetic code that can be and that cannot be correlated from the above given data.

Cleistogamy can favour only autogamy. Justify

What are the different types in which genes could be delivered during gene therapy?

The following graph shows the species-area relationship. Answer the following question as directed.

1. Name the naturalist who studied the kind of relationship shown in the graph. Write the observation made by him.
2. Write the situations as discovered by the ecologists when the value of 'Z' (slope of the line) lies.

1. 0.1 and 0.2
2. 0.6 and 1.2

What does 'Z' stand for?

3. When would the slope of the line 'b' become steeper?

Describe any three functions of hypothalamus.

AtRNA is charged with the amino acid phenylalanine.

1. At what end of the tRNA is the amino acid attached?
2. What is the mRNA codon that codes for phenylalanine?
3. Name the enzyme responsible for this attachment.