Give reasons, at higher altitudes, people suffer from a disease called anoxia. In this disease, they become weak and cannot think clearly?

What is that prevents a child to suffer from a disease he/ she is vaccinated against? Give one reason.

In a group of 400 people, 160 are smokers and non-vegetarian, 100 are smokers and vegetarian and the remaining are non-smokers and vegetarian. The probabilities of getting a special chest disease are 35%, 20% and 10% respectively. A person is chosen from the group at random and is found to be suffering from the disease. What is the probability that the selected person is smoker and non vegetarian ?

Give reasons for the following : Copper cannot displace zinc from its salt solution..

In old age, people often suffer from stiff and inflamed joints. What is this condition called? What are the possible reasons for these symptoms?

The organisms which carries a disease from one organism to another is called