The life cycle of a malarial parasite is shown below:

(a)
(b) The virus is called retro virus because its genetic material is RNA that is transcribed to DNA using enzyme reverse transciptase.
(c) Yes, the infected cell can survive, while viruses are being replicated and released.

The process by which retrovirus gains entry into human host body or the mechanism by which AIDS virus causes immunodeficiency is as follows:

Recombinant DNA vaccines are made up of a small circular DNA (plasmid) that has very tiny piece of pathogen DNA incorporated in it to produce one or two specific proteins of the pathogen.
This recombinant DNA is introduced into the bacteria or yeast cells, where it can use cell's machinery to produce polypetides of pathogen.
These are used as vaccines to trigger a range of immune responses. Vaccines produced by using this approach allow large scale production, e.g.
(i) Hepatits-B vaccines produced from yeast.
(ii) Bird flu DNA vaccine.
Advantages
(i) Recombinant DNA vaccines are advantageous over killed or attenuated vaccines since, they do not get virulent or mutated again as it is seen in case of attenuated vaccines.
(ii) Secondly these are highly pure, specific and elicit strong immune response.

(i) He consumed uncovered food products and drinks which got contaminated by pathogenic microbes.
(ii) This practice helps in preventing spread of infectious diseases.

(a) 

(b) The carcinogens are asbestos, gamma rays, tobacco smoke and arsenic.
(c) Detection and diagnosis of cancer depends upon histological features of malignant structure.
(i) Biopsy of bone marrow and abnormal count of WBCs is done in leukemia.
(ii) Pap test (cytological staining) is used for detecting cancer of cervix and other genital tract parts.
(iii) Radiography, CT scan (Computed Tomography), Magnetic Resonance Imaging (MRI scan) are useful technique to detect cancer of internal organs.

Primary atypical pneumonia is a community-acquired pneumonia caused by Mycoplasma pneumoniae which lacks the cell wall.Due to absence of cell wall,it is resistant to enzymes and penicillin

Pulse Polio Programme was started in 1978.Pulse Polio programme is the administration of oral Polio vaccine at regular intervals to the children under the age of five.Government provides vaccine free of cost.Many NGOs also participate with a mission to make India free of polio disease OPV is the vaccine given orally.The project 'Fight poliomyelitis' through a large cycle vaccination programme and monitoring for polio cases.F Due to this project, on march 27,2014 World Health Organization declared India a polio free country since no cause of wild polio had been reported. 

It is true that once a person gets entangled in the deadly whirlpool of alcohol or drugs, it is very difficult to get rid of this habit because, in the absence of a continuous supply of alcohol/drugs, the person starts showing certain symptoms called withdrawal signs which are listed below:
(1) Anxiety  
(2) Shakiness
(3) Nausea  
(4)Sweating.

Asexual Phase
It occurs in the human host. The sporozoites enter the human body through the bite of an infected female Anopheles mosquito.
They reach the liver through blood and multiply within the liver cells.
Such liver cells burst and release the parasite into blood.
The parasite enters RBCs, multiply in them and cause their rupture.
The rupture of RBCs is associated with the release of a toxin, called haemozoin, which is responsible for the chill/shivering and the high temperature (fever) of the body. Sexual Phase
It starts with the formation of gametocytes in the RBCs of man.
The parasite then enters the female Anopheles mosquito, along with the blood when it bites the infected person.
Further development occurs in the stomach wall of mosquito.
The gametes fuse to form a zygote. The zygote undergoes further development to form sporozoites.
Sporozoites are transported to and stored in the salivary glands of the mosquito and are transferred to a human body during the bite of the mosquito.