Chapter 15

Question 1

Vertebrates

Answer 1

an animal with a bony or cartilaginous backbone

Question 2

descent with modification

Answer 2

Darwin’s term for evolution
- all living things are related
- organisms change over time as a result of natural selection

Question 3

fossil record

Answer 3

an assemblage of fossils arranged in order of age. (This provides evidence of changes in species over time)

Question 4

Paleontologists

Answer 4

a scientist who studies ancient life by examining fossil records

Question 5

Radiometric dating

Answer 5

the use of radioactive isotopes as a measure for determining the age of a rock or fossil.

Question 6

Relative dating

Answer 6

Determining the age of fossils from its position relative to layers of rock

Question 7

Invertebrates

Answer 7

animals with no backbone

Question 8

Tetrapods

Answer 8

a vertebrate animal with four true limbs - that is jointed, bony appendages with digits.
(mammals, amphibians, birds, and reptiles)

Question 9

Vestigial structures

Answer 9

A structure inherited from an ancestor that no longer serves a clear function in the organism that possesses it.