Science unit 7

Question 1

Embryo

Answer 1

The young organism that develops from a
zygote.

Question 2

Homologous structures

Answer 2

Structures that are similar in different species and that have been inherited from a common ancestor.

Question 3

Fossil record

Answer 3

All the fossils that have been discovered and what scientists have learned from them.

Question 4

Competition

Answer 4

The struggle between organisms to survive as they attempt to use the same limited resources in the same place at the same time.

Question 5

Variation

Answer 5

differences between individuals within a species, or between different species

Question 6

Extinct

Answer 6

Term used to refer to a group of related organisms that has died out and has no living members.

Question 7

Natural selection

Answer 7

The process by which organisms that are best adapted to their environment are most likely to survive and reproduce.

Question 8

Scientific theory

Answer 8

A well-tested explanation for a wide range of observations or experimental results.

Question 9

Evolution

Answer 9

Change over time; the process by which modern organisms have descended from ancient organisms.

Question 10

Adaptation

Answer 10

An inherited behavior or physical characteristic that helps an organism survive and reproduce in its environment.

Question 11

Fossil

Answer 11

The preserved remains or traces of an organism
that lived in the past.

Question 12

Species

Answer 12

A group of similar organisms that can mate with each other and produce offspring that can also mate and reproduce.