Extraordinary decrease in the number of leucocytes is called

1. leucopenia
2. leukemia
3. myopia
4. embolism

The passage of white blood corpuscles through unruptured wall of blood vessels is known as

1. diapedesis
2. haemopoiesis
3. phagocytosis
4. cyclosis

X-ray machine operator have to take special care to avoid exposure of X-rays.

Which of the following reasons support this statement?

P. X-ray damage the body cells.
Q. Too frequent exposure may cause genetic variations, bone cancer etc.
R. Too much X-rays exposure are not harmful.

1. Only P
2. Only Q
3. Only P and Q
4. Only Q and R

The average ratio of male to female individuals based on XX and XY type of sex-determination, in a human population is

1. 3:1
2. 1:3
3. 1:4
4. 1:1