The skin helps maintain core body temperature by changing the amount of blood flowing through its blood vessels.
When the body is too hot
Arterioles dilate → vasodilation.
More blood flows through the skin's capillary networks.
More heat is brought from the body core to the skin surface.
Heat is transferred to the surroundings by radiation, conduction and convection.
Definition
A dichotomous key is a scientific tool used to identify unknown organisms based on their observable characteristics.
It consists of a series of paired, contrasting statements.
Each pair provides two possible choices, leading to the next step or to the identification of the organism.
Principles
Each step contains two alternatives.
1. What is matter?
Matter is anything that:
Has mass
Takes up space (volume)
Is made of particles
The particles in matter are constantly moving.
1. Solid
Fixed shape and volume
Particles are tightly packed.
Strong forces hold particles together.
Particles vibrate around fixed positions.
Very difficult to compress.
