Reproduction in animals — Science STD 8 — Question

Which of the two spreads dengue: mosquito or housefly?

Which gas in the upper atmosphere prevents ultraviolet radiations of the sun from reaching the earth?

Name the endocrine gland which secrets the growth hormone.

What makes these strings vibrate?

What name is given to the cutting and gathering of a food crop like wheat or paddy?

One student says that water exerts pressure on the bottom of the bucket but another student says that water exerts pressure on the sides of the bucket. What would you like to say?

Name an important source from which naphthalene balls are obtained.

Two tiny holes are made in a plastic bucket, one near the middle part and the other just above bottom when this bucket is filled with water, the water rushes out from the bottom hole much faster than from the upper hole. What conclusion do you get from this observation?

What is the full form of CNG?

Which force is responsible for the wearing out of car tyres?