Science (English Medium) Class 12 - CBSE Important Questions for Biology

Identify ‘a’ and ‘b’ in the figure given below representing proportionate number of major vertebrate taxa.

Why should we conserve biodiversity ? How can we do it?

'in-situ' Conservation can help endangered/threatened species. Justify the statement.

Name and describe any three causes of bio-diversity losses.

Explain the concept of "co-extinction" by taking two examples.

List any three major causes of loss of biodiversity.

Enlist two criteria that are used to identify a region for maximum protection as 'Biodiversity hotspots'.

"Forests provide intangible benefits to us." Explain by taking three different areas, how.

The IUCN Red Data List (2004) in the last 500 years documents the extinction of nearly 784 species including ______.

State what is apomixis. Comment on its significance. How can it be commercially used?

Explain any three advantages that seeds offer to angiosperms.

Explain the monosporic development of the embryo sac in the ovule of an angiosperm.

With the help of a neat, labelled diagram describe the human male reproductive system.

Describe the role of pituitary and ovarian hormones during the menstrual cycle in a human female.

Name and explain the role of the inner and middle walls of the human uterus.

Write the location and function of the Sertoli cells in humans.

Arrange the following hormones in sequence of their secretion in a pregnant woman. 

hCG, LH, FSH, Relaxin

Draw a graafian follicle and label antrum and secondary oocyte.

Draw a diagram of a mature human sperm. Label any three parts and write their functions.

Draw a label diagram.
Draw a labeled diagram to show the interrelationship of four accessory ducts in a human male reproductive system.