If someone belongs to the blood group B, he has B antigens on the surface of his red blood cells and A antibodies in his blood plasma. So he can donate blood to persons of B and AB blood groups, but cannot receive blood from persons having B or O groups.

Correct Option: D

If someone belongs to the blood group B, he has B antigens on the surface of his red blood cells and A antibodies in his blood plasma. So he can donate blood to persons of B and AB blood groups, but cannot receive blood from persons having B or O groups.

The stomach is a muscular, hollow, dilated part of the digestion system which functions as an important organ of the digestive tract in some animals, including vertebrates. It secretes protein-digesting enzymes called protease and strong acids to aid in food digestion.

Correct Option: B

The stomach is a muscular, hollow, dilated part of the digestion system which functions as an important organ of the digestive tract in some animals, including vertebrates. It secretes protein-digesting enzymes called protease and strong acids to aid in food digestion.

In humans, vitamin D is unique because the body can synthesize it (from cholesterol) when sun exposure is adequate (hence its nickname, the "sunshine vitamin").Very few foods in nature contain vitamin D. The flesh of fatty fish (such as salmon, tuna, and mackerel) and fish liver oils are among the best sources.

Correct Option: C

In humans, vitamin D is unique because the body can synthesize it (from cholesterol) when sun exposure is adequate (hence its nickname, the "sunshine vitamin").Very few foods in nature contain vitamin D. The flesh of fatty fish (such as salmon, tuna, and mackerel) and fish liver oils are among the best sources.

We have two ears basically to widen the scope of hearing so that we can find out where sounds are coming from, and from what distance; i.e., sound localization. The brain utilizes subtle differences in intensity, spectral, and timing cues to allow us to localize sound sources

Correct Option: D

We have two ears basically to widen the scope of hearing so that we can find out where sounds are coming from, and from what distance; i.e., sound localization. The brain utilizes subtle differences in intensity, spectral, and timing cues to allow us to localize sound sources

The Ostrich is the largest living species of bird. They usually weigh from 63 to 145 kilograms. Although it cannot fly, the ostrich is also the fastest-running bird today; it can run up to about 70 kilometres in an hour.

Correct Option: C

The Ostrich is the largest living species of bird. They usually weigh from 63 to 145 kilograms. Although it cannot fly, the ostrich is also the fastest-running bird today; it can run up to about 70 kilometres in an hour.