Biodiversity and Conservation — BIOLOGY STD 12 Science — Question

Explain the concept of the Blue Revolution.

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

During an excavation assignment, scientists collected pollen grains of a plant preserved in deeper layers of soil. Analyse the properties of pollen grains which help in the fossilization.

The term ‘desirable trait’ can mean different things for different plants. Justify the statement with suitable examples.

Give the name and character of the disease caused by Antamoeba histolytica, Trichophyton and wucheria in human.

1. Which insects are killed by Bacillus thuringiensis?
2. The Bt binds to which cells?
3. In which plants Bt toxin is used?

Besides better aeration and mixing properties, what other advantages do stirred tank bioreactors have over shake flasks?

While creating genetically modified organisms, genetic barriers are not respected. How can this be dangerous in the long run?

A person has to perform crosses for the purpose of studying inheritance of a few traits/ characters. What should be the criteria for selecting the organisms?

(i) EcoRI has played a very important role in recombinant DNA technology.
(a) Explain the naming convention of Eco RI.
(b) Write the name of the recognition site and cleavage site of this restriction enzyme.
(ii) What is the longitudinal extension of DNA produced by these restriction enzymes called? Describe their role in the formation of r-DNA.