Homeostasis

Question 1

homeostasis

Answer 1

Ability of an organism to maintain a constant internal environment

Question 2

external

Answer 2

surrounds outside of organism
(eg air temperature)

Question 3

internal

Answer 3

surrounds cells inside organism

Question 4

homeostasis in humans

Answer 4

body temperature - 37*C

pH of blood - 7.4

preventing buildup of toxic chemicals in body (excretion)

Sufficient oxygen levels

Heart rate and blood pressure

Question 5

How are substances moved in organisms?

Answer 5

Diffusion, osmosis, active transport

Question 6

diffusion

Answer 6

Movement of substance from area of high concentration to an area of low concentration (passive process)

Question 7

Osmosis

Answer 7

movies of the water from area of high concentration to an area of low concentration across a semipermeable membrane (passive process)

Question 8

Active transport

Answer 8

Movement of substances from area of low concentration to an area of high concentration (active process)

Against a concentration gradient

Requires energy of the form ATP

Question 9

Exchange in small organisms

Answer 9

special organs of exchange are not needed in small organisms as diffusion is adequate (e.g. amoeba)

Question 10

Methods to improve exchange

Answer 10

flat structures

Respiratory system with a large surface area

Respiratory and excretory systems (take minerals from within the body to body surface)

Question 11

What do you large organisms need for exchange?

Answer 11

Circulatory system to carry long distances

Question 12

Need for homeostasis

Answer 12

allow cells to function at most efficient rate

allows organisms to function independently of external conditions

Allow slight changes in internal environment when necessary