Read and listen to the story online: [bad word] /www.bbc.co.uk/worldservice/learningenglish/general
/sixminute/2012/0/120315_6min_english_extinct_men.shtml

Vocabulary and definitions:
• chromosome - a very small [bad word] in animal or plant cells
• hormones - chemical substances in the body that influence cell function
• pessimistic - expecting bad things to happen
• ratio - numerical expression of the
relative sizes between two or more values
• extinction - a situation in which a life form stops existing
• breathe a sigh of relief - feel happy that something unpleasant stops
• depleted - reduced by a large amount
• genes - units in cells that control qualities passed on through generations
• natural selection - a process in nature that determines chances of survival
• stereotypes - a fixed idea or image that people have about something 
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