Organisms and Populations — BIOLOGY STD 12 Science — Question

Enumerate the conclusions made by A. Wallace from his studies on life forms.

What is fragmented habitat? Give one example.

In a flowering plant a microspore mother cell produce four male gametophytes while a megaspore mother cell form only one female gametophyte. Explain.

Explain the role of baculovirus as biological control agents. Mention their importance in organic farming. ###Name a genus of baculovirus. Why are they considered good biocontrol agents?

Why do we prefer to call secondary waste water treatment as biological treatment?

What is active immunity?

A cistron consists of 20 codons. How many amino acids will it code in the polypeptide transcribed? Why?

Sperms have a tail, whereas eggs do not. Why?

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.

Mention two strategies evolved to prevent self-pollination in flowers.