heart

Question 1

what is the relationship between the size of an organism and its SA: volume ratio

Answer 1

. the larger the organism the smaller the SA:Volume ratio
. the smaller the organism the larger the SA:Volume ratio

Question 2

why do larger organisms require transport systems

Answer 2

smaller SA:Volume ratio so diffusion is less

Question 3

how do vaccinations work

Answer 3

1. a dead or weakened form of a pathogen is entered into the body
2. the stimulate the immune system
3. lymphocytes produce antigens
4. when the actual pathogen is entered the memory cells can produce lymphocytes faster.

Question 4

what is double circulatory system

Answer 4

the heart pumps blood twice per cycle

Question 5

what are the for components in the blood

Answer 5

1. white blood cells
2. red blood cells
3. platelets
   4.plasma

Question 6

how do the eyes protect from microorganisms

Answer 6

tears acts as an antiseptic

Question 7

how does the skin protect from microorganisms

Answer 7

acts as a barrier

Question 8

how does the goblet cells protect from microorganisms

Answer 8

produce mucus that traps pathogens

Question 9

how does the stomach acid protect from microorganisms

Answer 9

kills microbes entering the stomach

Question 10

how are red blood cells specialised

Answer 10

. large surface area to absorb oxygen
. haemoglobin carries oxygen
. flexible squeeze through small gaps

Question 11

what are the 3 main blood vessels

Answer 11

vein
capillary
artery

Question 12

what does the vein have

Answer 12

large lumen
thin walls
valves to prevent backflow

Question 13

what does the capillaries have

Answer 13

one cell thick
short diffusion distance

Question 14

what does the artery have

Answer 14

large lumen
thick muscles wall

Question 15

what is the role of the coronary arteries

Answer 15

to supply heart muscle with oxygenated blood