Adolescence /ˌæd

extinction /ɪkˈstɪŋk.ʃ ə n/ noun [ U ]
a situation in which something no longer exists
The extinction of the dinosaurs occurred millions of years ago.
Many species of plants and animals are in danger of/threatened with extinction (= being destroyed so that they no longer exist) .
Some people predict the extinction of family life as we know it today.
fauna /ˈfɔː.nə/ /ˈfɑː-/ noun [ U + sing/pl verb ] specialized
all the animals that live wild in a particular area
an expedition to explore the flora and fauna of Hornchurch Wood
flora /ˈflɔː.rə/ /ˈflɔːr.ə/ noun [ U ] specialized
all the plants of a particular place or from a particular time in history
the flora of the Balearic Islands
Stone Age flora
genetics /dʒəˈnet.ɪks/ /-ˈnet ̬-/ noun [ U ]
the study of how, in all living things, the characteristics and qualities of parents are given to their children by their genes
habitat /ˈhæb.ɪ.tæt/ noun [ C or U ]
the natural environment in which an animal or plant usually lives
With so many areas of woodland being cut down, a lot of wildlife is losing its natural habitat.