Science (English Medium) कक्षा १२ - CBSE Question Bank Solutions for Biology

How do ecologists estimate the total number of species present in the world?

How has the development of bioreactor helped in biotechnology?

Name the most commonly used bioreactor and describe its working.

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

One of the major contributions of biotechnology is to develop pest-resistant varieties of cotton plants. Explain how it has been made possible.

Name and explain the technique used for separating DNA fragments and making them available for biotechnology experiments.

Differentiate between vas deferens and vasa efferentia.

Differentiate between spermatogenesis and spermiogenesis.

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

Answer the following question:
Name the group of bacteria involved in setting milk into curd. Explain the process they carry in doing so. Write another beneficial role of such bacteria.

Answer the following question:
Why does 'Swiss Cheese' develop large holes?

What is the cell that receives a recombinant gene called?

Give a reason why :
Proteases are added during the isolation of DNA for genetic engineering.

Name the microbes that help the production of the following product commercially:
Citric acid

The ______ lead to vas deferens that ascends to the ______ and loops over the ______.

Which of the following is a transporting tube leading from the bladder to which brings urine outside the body via penis?

The enlarged end of penis is covered by a loose fold of skin is called ______.

Vasa efferentia are the ductules leading from ______.

Which of the following produces sperms in spermatogenesis?

In the process of spermatogenesis, first maturation division is called ______.