Evolution — BIOLOGY STD 12 Science — Question

What is meant by the term ‘hot spots’ in biodiversity? List two criteria used for determining a ‘hot spot’. Name two hot spots of India.

Enumerate the steps which are involved in recombinant DNA technology.

1. A bacterial cell is shown in the figure given below. Label the part 'A' and 'B'. Also mention the use of part 'A' in rDNA technology.

2. Suppose a linear DNA fragment and a plasmid has three restriction sites for EcoRI. How many fragments will be produced from linear DNA and plasmid, respectively.

Describe the endosperm development in angiosperms.

Answer the following questions:
What are mycorrhiza? How does it act as a biofertiliser?

Given below are the events that are observed in an artificial hybridisation programme. Selection of parents → Emasculation → Bagging → Collection of pollen from other male plant → Dusting of pollen on stigma — Rebagging.
While, planning for crop improvement involving dioecious plants, which of the above mentioned steps would not be relevant?

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?

Differentiate between an annual and a biennial plant. Provide one example of each.

Ecosystem can be visualised as a functional unit of nature. Explain how?