the need for a transport system

Question 1

why does large multicellular organisms not rely on diffusion to move substances in and around the body

Answer 1

size
surface area to volume ratio
metabolic rate
transporting molecules such as food, hormones, enzymes and waste products of metabolism

Question 2

how much transporting material affect the need for a transport system

Answer 2

hormones and enzymes often produced by a gland in one part of body, required in another part

Question 3

what does the circulatory system require

Answer 3

a heart
a fluid which substances are transported
vessels through which fluid can flow

Question 4

types of circulatory system

Answer 4

open, closed

Question 5

what is a closed circulatory system

Answer 5

blood enclosed in vessels
higher pressure and flow rate
exchange at capillaries by diffusion

Question 5

what is an open circulatory system

Answer 5

consist of heart and haemolymph through short vessels into haemocoel

exchange of compounds by diffusion
direct contact with cells and tissue
blood pumped into open space not enclosed in vessels

Question 5

what can closed circulatory system be

Answer 5

single double

Question 6

single circulatory

Answer 6

blood passes through heart once in complete circuit

Question 7

double circulatory

Answer 7

blood passes through heart twice in complete circuit
higher pressure and flow rate
can change pressure in specific regions