8B Science MIDterm Vocab

Sliding friction

When two solid surfaces slide across each other.

Static friction

Acts on objects when they are resting on a surface.

Fluid friction

When a solid object moves through a fluid.

Species

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

Competition

The struggle among living things to get the necessary amount of food, water, and shelter.

Fitness

How well an organism can survive and reproduce in its environment.

Coevolution

The process by which two species evolve in response to changes in each other over time.

Sexual Selection

Natural selection that acts on an organism's ability to get the best possible mate.

Fossil

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

Adaption

An inherited behaviour or physical characteristic that helps an organism survive and reproduce on its environment.

Scientific Theory

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

Evolution

The process by which modern organisms have descended from ancient organisms.

Mechanism

The natural process by which something takes place.

Natural Selection

A process by which individuals that are better adapted to their environment are more likely to survive and reproduce than other members of the same species.

Motion

The state in which one object’s distance from another is changing.

Reference point

A place or object used for comparison to determine if an object is in motion.

Force

A push or pull exerted on an object.

Net force

The overall force on an object when all the individual forces acting on it are added together.

Speed

The distance an object travels per unit of time.

Slope

The steepness of a graph line; the ratio of the vertical change (the rise) to the horizontal change (the run).

Acceleration

The rate at which velocity changes.

Velocity

Speed in a given direction.

Variable

A letter or symbol that represents a number that can change.

Fossil Record

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

Homologous Structures

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

Embryo

A young organism that develops from a fertilized egg (called a zygote).

Extinct

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

Protein

Large organic molecule made of carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur.

Endosymbiosis

A relationship in which one organism lives inside another organism’s cells.

Average

A value that falls directly in the middle of other related values.

Newton

A unit of measure that equals the force required to accelerate 1 kilogram of mass at 1 meter per second.

Friction

The force that two surfaces exert on each other when they rub against each other.

Gravity

The attractive force between objects; the force that moves objects downhill.

Inertia

The tendency of an object to resist a change in motion.

Weight

A measure of the force of gravity acting on an object.

Rolling friction

When an object rolls across a surface, \__________ occurs.