Human Health and Disease — BIOLOGY STD 12 Science — Question

Unless the vector and source DNAs are cut, fragments separated and joined, the desired recombinant vector molecules cannot be created.

1. How are the desired DNA sequences cut?
2. Explain the technique used to separate the cut fragments.
3. How are the resultant fragments joined to the vector molecule?

What is cancer? Write the main types of cancer. Name at least three deadly signs of cancer.

Describe diagrammatically the male reproductive organs.

Describe fertilization in flowering plants.###Describe the development of female gametophyte and double fertilization in angiosperms.

Define an operon. giving an example, explain an Inducible operon.

Describe various methods of contraception for the population control.###What are the main types of methods of birth control?###Discuss use of Various Contraceptive measures used for population.

Sunny was rushed to a nearby hospital after an accident, which had caused too much blood loss. The hospital failed to supply 'O' negative blood for transfusion. Ahmed, who was attending a patient there, heard about the situation and agreed to donate blood as he had the same blood group. Sunny's mother initially refused but was later convinced by her daughter's view.

1. Why cannot 'O' positive blood be transfused into Sunny's body?
2. What is the genetic basis of blood group inheritance?
3. Human blood grouping is an example of?
4. What values do you find in Sunny's sister and Ahmed?

With a neat, labelled diagram, describe the parts of a typical angiosperm ovule.

Describe in sequence the process of spermatogenesis in humans.