Q5 of 40 Page 1

List two advantages of the use of unleaded petrol in automobiles as fuel.

• The unleaded petrol doesn’t contain any lead, hence, doesn’t inactivate the catalytic converter of the vehicle.


• Due to the absence of lead, the harmful substances are not emitted. Therefore, helps in reducing pollution and preventing health problems like bronchitis, asthama and lung diseases.


More from this chapter

All 40 →
3

Retroviruses have no DNA. However, the DNA of the infected host cell does possess viral DNA. How is it possible?

 4

Why do children cured by enzyme-replacement therapy for adenosine deaminase deficiency need periodic treatment?

 6

Why do moss plants produce very large number of male gametes? Provide one reason. What are these gametes called?

 7

(a) Select the homologous structures from the combinations given below :

(i) Forelimbs of whales and bats


(ii) Tuber of potato and sweet potato


(iii) Eyes of octopus and mammals


(iv) Thorns of Bougainvillea and tendrils of Cucurbita


(b) State the kind of evolution they represent.