Why is it desirable to use unleaded petrol in vehicles fitted wi

Subject

Biology

Class

CBSE Class 12

Pre Boards

Practice to excel and get familiar with the paper pattern and the type of questions. Check you answers with answer keys provided.

Sample Papers

Download the PDF Sample Papers Free for off line practice and view the Solutions online.
Advertisement

 Multiple Choice QuestionsShort Answer Type

1.

How do the pollen grains of Vallisneria protect themselves? 

1657 Views

2.

Name the respective pattern of inheritance where F1 phenotype

(a) does not resemble either of the two parents and is in between the two.

(b) resembles only one of the two parents.

989 Views

3.

Write the name of the following: 

(a) The most common species of bees suitable for apiculture

(b) An improved breed of chicken

421 Views

4.

Mention the role of cyanobacteria as a biofertiliser. 

610 Views

Advertisement
5.

How is the entry of only one sperm and not many ensured into an ovum during fertilisation in humans? 

866 Views

6.

Where is acrosome present in humans? Write its function

606 Views

7.

State the significance of Coelacanth in evolution. 

964 Views

Advertisement

8.

Why is it desirable to use unleaded petrol in vehicles fitted with catalytic converters?


It is desirable to use unleaded petrol in the automobiles fitted with catalytic converter because lead in the petrol inactivates the catalyst.

658 Views

Advertisement
Advertisement
9.

(a) Where do the signals for parturition originate from in humans?

(b) Why is it important to feed the newborn babies on colostrums? 
701 Views

10.

Given reasons for the following: 

(a) The human testes are located outside the abdominal cavity.

(b) Some organisms like honey-bees are called parthenogenetic animals.

463 Views

Advertisement