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

Enlist the steps of controlled cross pollination. Would emasculation be needed in a cucurbit plant? Give reasons for your answer.

Give any two microbes that are useful in biotechnology.

(i) Write what differences you see in the Darwin’s finches shown above.
(ii) How did Darwin explain the existence of different types of finches on galapagos?

Given below is one of the strands of a DNA segment
3' TACGTACGTAACGTACG 5'
(a) Write its complementary strand.
(b) Write a possible RNA strand that can be transcribed from the above DNA molecule formed.

How and why is the bacterium Thermus aquaticus employed in DNA technology? Explain.

Or

Name the source of the DNA polymerase used in PCR technique. Mention why it is used?

Or

Give the name of the organism from where the thermostable DNA polymerase is isolated. State its role in genetic engineering.

Name the type of curve that characterises most population growing in favourable environment. Also define carrying capacity.

Female reproductive organs and associated functions are given below in column A and B. Fill in the blank boxes.

Column A	Column B
Ovaries	Ovulation
Oviduct	A
B	Pregnancy
Vagina	Birth

 Describe sexually transmitted diseases. Name some important STDs and their causative agents.

Fed up of a large family, a couple wanted to adopt a terminal method of contraception. Describe the process conducted by the doctor in either of the cases-male/ female partner.

If abiotic origin of life is in progress on a planet other than earth, what should be the condition there? Explain.