B14 Genetics and evolution Flashcards
What are fossils?
remains of organisms from millions of years ago, found in rocks
How might fossils be formed?
• parts of an organism do not decay because the conditions needed for decay are absent
• traces of organisms are preserved
• parts of an organism are replaced by minerals
What are the benefits of the fossil record?
can learn how species changed and life developed on Earth, and can track the movement of species across the world
What are the problems with the fossil record?
• many early organisms were soft-bodied so left few fossils
• gaps in the fossil record as not all fossils have been found and some have been destroyed
What is extinction?
no individuals of a species are still alive
What is the binomial system?
naming of organisms by their genus and species
What classification system did Carl Woese introduce?
three-domain system of Archaea, Bacteria, and Eukaryota
Why can bacteria evolve rapidly?
they reproduce at a fast rate
How do antibiotic-resistant strains of bacteria develop?
mutations that allow the strain to survive and reproduce
