Questions

In transfusions of packed red blood cells, individuals with type O Rh D negative blood are often called universal donors. Those with type AB Rh D positive blood are called universal recipients.

The immune system of a person with AB blood will accept blood from all possible donors, whether they have O, A, B, or AB blood. Since both A and B antigens are present in a person with AB blood, the recipient won't reject the blood. The body identifies that blood as "self" rather than "foreign."

Primary productivity refers to plants that make their own food using sunlight, water and availability of nutrients. Hence, they are not limited by time.

Ans. Let radius of the base and height of the cone be ‘r’ & ‘h’ respectively.

Then volume of cone = πr2h/3 For cylinder, radius is reduced by 4 times = r/4 And,  height is increased by 8 folds = 8h Volume of cylinder = πR2H = π(r/4)2 (8h) = (16/8)πr2h = πr2h/2 Ratio of volume of cone to volume of cylinder = (πr2h/3) : (πr2h/2) Or, Ratio = 2 : 3.