Ecosystems and Energy Flow — BIOLOGY STD 12 Science — Question

A male honeybee has 16 chromosomes whereas its female has 32 chromosomes. Give one reason.

What is GEAC and what are its objectives?

Shark is eurythermal, while polar bear is stenothermal. What is the advantage the former has and what is the constraint the latter has?

i. Hairy leaves in wheat
ii. Nectar-less cotton having smooth leaves
iii. Hairy leaves in cotton
iv. Solid stem in wheat

Resistance to insects	Morphological characters
Jassids	————
Cereal leaf beetle	————
Stem borers	————–
Bollworms	—————

Explain the following in context of cancer:
Benign tumour.

What is ozone shield and why is it important? Name the gases that cause stratospheric ozone depletion.

Collect 5 examples of palindromic DNA sequences by consulting your teacher. Better try to create a palindromic sequence by following base-pair rules.

ELISA technique is based on the principles of antigen-antibody interaction. Can this techique be used in the molecular diagnosis of a genetic disorder, such as phenyketonuria?

Angiosperms bearing unisexual flowers are said to be either monoecious or dioecious. Explain with the help of one example each.

Mention the major cause of air pollution in metro cities. Write any three ways by which it can be reduced.