Human Reproduction — BIOLOGY STD 12 Science — Question

What is the principle of Gel electrophoresis? Name the compound used for staining DNA to be used in recombinant technology. What is the colour of such stained DNA?

Name any six venereal diseases.

For flower colour in pea, the allele for purple flower (P) is dominant to the allele for white flower (p). A purple flowered plant therefore could be of genotype PP or Pp. What genetic cross would you make to determine the genotype of a purple flowered plant? Explain how your cross gives you the correct genotype of the purple flowered plant?

What do you mean by reproductive health? Mention the different ways in which people are made aware of the significance of reproductively healthy society.

Study the pedigree chart given above, showing the inheritance pattern of blood groups in a family and answer the following questions:

1. Give the possible genotypes of the individuals 1 and 2.
2. Which antigen or antigens will be present on the plasma membranes of the RBCs of individuals 5 and 9?
3. Give the genotypes of the individuals 3 and 4.

Given below is a list of autotrophs and heterotrophs. With your knowledge about food chain, establish various linkages between the organisms on the principle of ‘eating and being eaten’. What is this inter-linkage established known as?
Algae, hydrilla, grasshopper, rat, squirrel, crow, maize plant, deer, rabbit, lizard, wolf, snake, peacock, phytoplankton, crustaceans, whale, tiger, lion, sparrow, duck, crane, cockroach, spider, toad, fish, leopard, elephant, goat, Nymphaea, Spirogyra.

Diseases like dysentery, cholera, typhoid etc. are more common in over crowded human settlements. Why?

Write the specific symptoms of acquired immunity.

Write a short note on extinct species?