Chapter 16 Flashcards
Radioactive isotopes
a form of an element that decays into another element by radiation
Half-life
the time it takes for half the isotope in a sample to break down
Sedimentary rocks
-are formed gradually over time
-made from the compaction of sand and dust
Igneous rocks
are formed suddenly due to volcanic eruptions.
Mass extinction percentage
an extinction of between 50% and 90% of all living species that occur relatively rapidly
Continental drift
The movement of the continents relative to one another over time
Plate tectonics
the theory that the Earth’s outer shell is made up of large plates that move slowly over the mantle
Convergent evolution
a process in which different species evolve similar traits or behaviors to adapt to similar environmental challenges, even though they are not closely related
Taxonomy
the identification, naming, and classification of organisms on the basis of shared traits
Pyhlogeny
the evolutionary history of a group of organisms
Phylogenetic tree
A branching diagram of relationships showing common ancestry
similar to a family tree
Adaptive radiation
when several new species rapidly develop from a single ancestral species
Biogeography
the study of species distributions across the planet
Cell theory
- all living things are made of cells
- cells come from other cells
- cells are the basic unit
Shared features of all cells
cell membrane
genetic material (DNA)
ribosomes
cytoplasm
