Human Reproduction — BIOLOGY STD 12 Science — Question

Explain any two devices by which autogamy is prevented in flowering plants.

Differentiate between male and female heterogamety.

Write a note on fossil evidence. State the method by which age of fossils is calculated.

Global carbon is fixed in the biosphere through photosynthesis. Explain any two ways by which carbon is returned to the atmosphere.

Why is it that the line of treatment for a genetic disease is different from infectious diseases?

Does our blood have proteases and nucleases?

Certain molecular processes are given in column (A). Provide the terms given to these processes in column (B), after selecting them from the terms:
Recombination, gene regulation, prokaryotic transcription, eukaryotic transcription, translation, replication, gene transfer, DNA fingerprinting

S.No.	Column A	Column B
(i)	DNA → DNA
(ii)	DNA → hRNA
(iii)	mRNA → Protein
(iv)	Repressor Protein + Operator → No  transcription

Explain drug dependence.

Name two drugs obtained from poppy plant. “These drugs are medically useful, but are often abused.' Taking the mentioned examples, justify by giving reasons.

OR

How are morphine and heroin related? Mention the effect each one of them has on the human body.

What are the major components of seminal plasma?