Human Health and Disease — BIOLOGY STD 12 Science — Question

Write a short note on Double fertilisation.

Answer the following questions:
What is amniocentesis and why there is a statutory ban on it?

Given below is the representation of amino acid composition of the relevant translated portion of B-chain of haemoglobin, related to the shape of human red blood cells.

1. Is this representation indicating a normal human or a sufferer from certain related genetic disease? Give reason in support of your answer.
2. What difference would be noticed in the phenotype of the normal and the sufferer related to this gene?
3. Who are likely to suffer more from the defect related to the gene representedthe males, the females or both males and females equally? And why?

What is the fate of trophoblast in mammalian embryo?

In cattle, hornless (H) is dominant over horned (h) and black (B) is dominant over red (b). Consider that these two pairs of genes assort independently.

1. What proportion of the offspring from the cross, BbHh x bbhh, would be black and hornless?
2. From the cross Bbhh x Bbhh, how many will be:

1. Black and horned.
2. Red and horned.

Given below is the representation of amino acid composition of the relevant translated portion of b-chain of haemoglobin, related to the shape of human red blood cells.

What difference would be noticed in the phenotype of the normal and the sufferer related to this gene?

One of the codons on mRNA is AUG. Draw the structure of tRNA adaptor molecule for this codon. Explain the uniqueness of this tRNA.

What are the measures one has to take to prevent from contracting STDs?

Write any four differences between birth rate and death rate.

A person is born with a hereditary disease with a weakened immune system due to deficiency of an enzyme. Suggest a technique for complete cure for this disease, identify the deficient enzyme and explain the technique used for cure.