Biotechnology: Principles and Processes — BIOLOGY STD 12 Science — Question

What is the significance of reflex action?

1. What is meant by ecological succession? Explain how it occurs.
2. What properties distinguish a pioneer community from a climax community?

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?

During a fire in an auditorium, a large number of assembled guests got burnt beyond recognition. Suggest and describe a modern technique that can help hand over the dead to their relatives.

Human female is referred to as carrier of colour blindness.

Explain the significance of satellite DNA in DNA fingerprinting technique.

Name the source of gonadotropins in human females. Explain the changes brought about in the ovary by these hormones during menstrual cycle.
OR
Describe how the changing levels of FSH, LH and progesterone during menstrual cycle induce changes in the ovary and the uterus in human female.

1. Mention the specific geographical region where these organisms are found.
2. Name and explain the phenomenon that has resulted in the evolution of such diverse species in the region.
3. Explain giving reasons the existence of placental wolf and Tasmanian wolf sharing the same habitat.

Give one example of disease caused each by fungi, bacteria and viruses in crop plant.

What are stem cells in a human embryo?