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

What is LAB? What is its role in human stomach?

Describe a palindrome with the help of an example.

Given below are the events that are observed in artificial hybridisation programme. Arrange them in the correct sequential order in which they are followed in the hybridisation programme.
(a) Re-bagging; (b) Selection of parents; (c) Bagging; (d) Dusting the pollen on stigma; (e) Emasculation; (f) Collection of pollen from male parent.

Discuss about the major programs that the Ministry of Environment and Forests, Government of India, has initiated for saving major Indian rivers from pollution.

How did the process of RNA interference help to control the nematode from infecting the roots of tobacco plants?

Or

How has RNAi technique helped to prevent the infestation of roots in tobacco plants by a nematode Meloidogyne incognita?

Name the two forms of reservoir of carbon that regulate the ecosystem carbon cycle.

In the following table of interspecific interactions, fill the blanks with (+) sign for beneficient interaction, (-) sign for detrimental and 0 for neutral interaction.

Species A	Species B	Name of  Interaction
+		Mutualism
	-	Competition
	-	Predation
+		Parasitism
+		Commensalism
	0	Amensalism

Describe the mechanism of inheritance of the ABO system of blood groups, highlighting the principle of genetics involved in it.

Discuss the genetic basis of wrinkled phenotype of pea seed.

Name the stage ofthe Plasmodium thall is trrnsmitted to human body by the vector. Describe the life cycle of the plrasite in humans.

OR

Trace the life cycle of Plasmodium in humans from the stage of entry, until it is picked up by the female Anopheles.