Human Reproduction — BIOLOGY STD 12 Science — Question

Mrs. Peter and Mrs. James had babies at the same hospital. Mrs. Peter took home a girl, Nancy and Mrs. James received a boy, Richard. However, Mrs. James was certain she gave birth to a girl and brought suit against the hospital. Blood tests showed that Mr. James was type O, Mrs. James was type AB and Mr. and Mrs. Peter were both type B. Nancy was type A and Richard was type O. List the possible genotypes of each individual and then indicate the correct parents for each child.
Genotypes :

1. Mrs. Peter ____________.
2. Mr. Peter ______________.
3. Nancy _____________.
4. Mrs. James _________________.
5. Mr. James ________________.
6. Richard _______________.
7. Whose baby is Nancy?
8. Whose baby is Richard?

In a Polymerase Chain Reaction (PCR), give the temperature required for the steps:

1. Denaturation.
2. Annealing.
3. Extension, respectively.

A dihybrid heterozygous round, yellow seeded garden pea was crossed with a double recessive plant.

1. What type of cross is this?
2. Work out the genotype and phenotype of the progeny.
3. What principle of Mendel is illustrated through the result of this cross?

List six advantages of "ex-situ" approach to conservation of biodiversity.

During a monohybrid cross involving a tall pea plant with a dwarf pea plant, the offspring populations were tall and dwarf in equal ratio. Work out a cross to show how it is possible.

Name the cell from which the endosperm develops in a coconut. Mention its ploidy. Explain the process of endosperm development in a coconut.

Construct an ideal pyramid of energy when 1,000,000 joules of sunlight is available. Label all its trophic levels.

It is established that RNA is the first genetic material. Explain giving three reasons.