Principles of Inheritance and Variation — BIOLOGY STD 12 Science — Question

Ignoring our traditional knowledge can we prove costly in the area of biological patenting. Justify.

What is cancer? Describe the types of tumors.

Mention any two measures for prevention and control of alcohol and drug abuse among adolescents.

1. You are given tall pea plants with yellow seeds whose genotypes are unknown. How would you find the genotype of these plants? Explain with the help of cross.
2. Identify a, b and c in the table given below:

S. No.	Pattern of inheritance	Monohybrid F1 phenotypic expression
i.	Co-dominance	a
ii.	b	The progeny resembled only one of the parents
iii.	Incomplete dominance	c

Bio-diversification of life started to occur almost 3 billion years ago. Since then new species have been evolving and then disappearing en masse from earth.
a. How many episodes of mass extinctions of species have already taken place and which one is in progress in the current era?
b. How is current episode in progress different from the previous episodes and why? Explain.

Explain the cause of chromosomal disorders in humans. Describe the effect of such disorders with the help of an example each involving.

1. autosomes, and
2. sex chromosomes.

Answer the following questions:
Describe the endosperm development in coconut.

Enlist the probable causes of infertility.

Mention the function of mitochondria in sperm.

Following the collision of two trains, a large number of passengers are killed. A majority of them are beyond recognition. Authorities want to hand over the dead to their relatives. Name a modem scientific method and write the procedure that would help in the identification of kinship.