Identify the diseases caused by protozoans:

Which one of the following diseases is not transmitted by mosquitoes?

Classify infectious agents into different categories and also mention the diseases caused by them.

Explain the following statement by giving two examples: 'It is not necessary that the pathogen affects an organ or tissue depending upon its point of entry.'

Study the given chart carefully and fill in the blanks $(a)$,$(b)$,and $(c)$:

$S$.No.	Name of the disease	Causative organism	Mode of transmission
$1$. Polio	$(a)$	Infection of virus directly/orally
$2$. $(b)$	Lyssa virus	Virus enters human body with saliva of an infected animal
$3$. Typhoid	Salmonella typhi	$(c)$

Name any two groups of micro-organisms from which antibiotics could be extracted.