This question already has an answer here:
Can we use "the" (definite article) with nouns to refer to a group of that name?
For example, on learnenglish.britishcouncil.org and this article said:
to say something about all the things referred to by a noun:
- The wolf is not really a dangerous animal (= Wolves are not really dangerous animals)
- The kangaroo is found only in Australia (= Kangaroos are found only in Australia)
- The heart pumps blood around the body. (= Hearts pump blood around bodies)
Is that really right?
Because I only saw in that site and I know that when "the" comes before adjectives it refers to a group of people.