[General] A lion/lion doesn't roar while he fights.

[arjitsharma]

In which context should I say the following?
1. A lion doesn't roar while he fights.
2. Lion doesn't roar while he fights.

I have seen sentence like this: Man is mortal. Why the "a" is not added before the word man?

 

[emsr2d2]

"Man" is used to refer to the whole of humankind so it's a collective noun. That's not the case with your example about lions. Sentence 2 is wrong.

A lion doesn't roar while fighting.
Lions don't roar while fighting.

I've changed "while he fights" to "while fighting" because not all lions are male. Female lions (lionesses) also fight.

 

[arjitsharma]

How many words are there to refer to the whole of a living thing or a non living thing?
I would like to know the list of it.

 

[emsr2d2]

"The animal kingdom" covers humans and fauna.
"Non-human animals" covers fauna but not humans.
"Flora" covers all plants.

Don't forget humans are animals.

(Not an anthropologist/botanist!)

 

[Rover_KE]

How many words are there to refer to the whole of a living thing or a non living thing?
I would like to know the list of it.

Google classification of living things ​and you'll probably get more than you bargained for!

 

[Tdol]

"Flora" covers all plants.

I think that some use fungi as a separate category.