definitions Flashcards
1
Q
radiometric dating
A
- an absolute method
- age of rocks and fossils can be determined accurately
- based on the tempo of radioactive decay
- measured in millions of years (MY - millions of years ; MYA - million of years ago)
- rocks contain radioactive isotopes of certain elements
- these decay at a constant rate
- age of rocks is determined by comparing the radioactive isotopes and their stable form
2
Q
eukaryote
A
an organism that does have a membrane-bound nucleus and specialised organelles
3
Q
prokaryote
A
an organism that does not have a membrane-bound nucleus and does not have any specialised organelles
4
Q
species
A
a group of living organisms with similar or the same traits where interbreeding and the exchange of genes occur
5
Q
extinction
A
the complete termination of a kind of organism or group of kind of organisms
6
Q
biodiversity
A
the variety of species within an ecosystem or the world
7
Q
fossil
A
the remains of dead organisms that are preserved in the rocks the Earth’s crust
