Reproduction in organisms — BIOLOGY STD 12 Science — Question

Explain the Zygote Intra Fallopian Transfer (ZIFT) technique. How is Intra Uterine Transfer Technique (IUT) different from it?

What do oral pills contain and how do they act as effective contraceptives?OR
Name the hormonal composition of the oral contraceptive used by human females. Explain how does it act as contraceptive?

If you squeeze a seed of orange you might observe many embryos of different sizes? How is it possible? Explain.

Suggest four advanced ex-situ methods to conserve threatened biodiversity.

Match the asexual reproductive structures in Column I with the organisms in Column II.

S.No.	Column I	S.No.	Column II
A.	Conidia	i.	Chlamydomonas
B.	Gemmules	ii.	Hydra
C.	Zoospores	iii.	Penicillium
D.	Buds	iv.	Sponges
		v.	Banana

Why is it essential that tRNA binds to both an amino acid and an mRNA codon during protein synthesis?

If a double stranded DNA has 20 per cent of cytosine, calculate the per cent of adenine in the DNA.

Apart from being a part of food chain, predators play other important roles. Mention any two such roles supported by examples.

What are the major components of seminal plasma?

Why are coral reefs not found in the regions from west Bengal to Andhra Pradesh but are found in Tamil Nadu and on the east coast of India?