(a) Advantages of correct postures: 

1. It improves the personality. 

2. It develops physical fitness and athletic ability. 

3. It gives grace and efficiency of movement. 

4. It prevents disorders and diseases. 

(b) Advantages of recreation: 

1. Recreation helps in reducing mental tension, illness and stress. 

2. Recreation plays an important role in encouraging such things as preservation of natural resources, construction of play grounds etc. 

3. Recreation recognizes the people to become all that they are capable of becoming and contribute to the society. 

4. It plays an important role in the life of children and youth by avoiding them from committing criminal acts. 

(c) Malaria is caused by a sporozoon parasite and carried from man to man by the agency of certain species of female anopheline mosquitoes. 

Symptoms: Body ache and Fever.

 (d) Immunity is the ability of an organism to resist a particular infection or toxin by the action of specific antibodies or sensitized white blood cells. 

Types of Immunity: Basically immunity is divided into two categories: 

1. Innate Immunity: It is the natural resistances with which a person is born. It provides resistances through several physical, chemical and cellular approaches. 

2. Adaptive Immunity: It is further divided in two major types natural and artificial. Naturally acquired immunity occurs through contact with a disease causing agent, when the contact was not deliberate, whereas artificially acquired-immunity develops only through deliberate actions such as vaccination.