module 3 - 8.1 transport systems in multicellular organisms Flashcards
1
Q
how can single celled organisms like bacteria and amoeba obtain nutrients and excrete waste?
A
diffusion
2
Q
what are the reasons a transport system is needed?
A
- metabolic rate
- SA:V
- transporting moleucles
3
Q
what is the metabolic rate like in large organisms and why?
A
- high MR
- high volume of substances and produce a lot of waste
- diffusion alone would not be able to intake and expel all the substances
4
Q
where are hormones and enzymes often produced and required?
A
produced in one part, required in a different part
- circulatory systems are used to transport substances
5
Q
what is a specialised circulatory system comprised of?
A
- a heart
- a fluid in which substances are transported (bulk flow)
- vessels that fluid can flow through
6
Q
what are the 2 types of circulatory systems?
A
- open
- closed
7
Q
what is an open circulatory system?
A
- consists of a heart that pumps haemolymph through short vessels into then haemocoel
- when the heart relaxes, haemolymph blood is sucked back in via pores called ostia
8
Q
what is a closed circulatory system?
A
- blood is fully enclosed within blood vessels at all times
- blood from heart if pumped through progressively smaller vessels
9
Q
which organisms have a double circulatory system?
A
complex organisms
