Paper 1 common 6 markers

Question 1

Describe the features of the blood vessels+their functions

Answer 1

> arteries carry the blood away from the heart at a high pressure
arteries have thick, elastic musclar walls to withstand the pressure, and a small lumen
veins carry blood into the heart at a low pressure
veins don’t hv thick walls, they have bigger lumen than arteries and valves to prevent backflow of blood
capillaries carry the blood to nearly every cell in the body to exchange substances
have permeable walls only 1 cell thick which increases rate of diffusion by decreasing distance

Question 2

Describe how leaves are adapted for photosynthesis

Answer 2

> upper epidermis has a waxy cuticle to prevent water loss and is transparent so light can pass through to chloroplasts
leaves are broad so large SA for gas exchange and light absorption
leaves are thin so short diffusion distance
lots of chloroplasts containing chlorophyll
air spaces in spongy mesophyll for CO2 and O2 to move
guard cells surround stomata controlling when they open and close for gas exchange

Question 3

Explain the advantage of having 2 circulatory systems rather than one

Answer 3

> blood pressure is much higher with 2
double means 2 circuits of blood vessels from the heart-one to body and one to lungs
for this humans need a 4 chambered heart
allows blood to be pumped separately
check this answer

Question 4

How is alcohol made?

Answer 4

> process is fermentation
yeast is used
alcohol is made
extracting sugar from source material
glucose is broken down
by anaerobic respiration
CO2 is produced
entry of air and other microorganisms should be prevented

Question 5

Describe how the coronary arteries can become narrowed and how this can lead to a heart attack

Answer 5

> if a person has a diet high in fats this can be linked to having high cholesterol
high cholesterol blocks the coronary arteries and causes plaques to form in the walls
blood can clot from plagues
finish this

Question 6

Describe how glucose from the small intestine is moved to a muscle cell(2)

Answer 6

> glucose is absorbed by diffusion into the bloodstream
the blood delivers glucose to muscles in capillaries

Question 7

Explain why having only one ventricle makes the circulatory system less efficient than having 2

Answer 7

> oxygenated and deoxygenated blood mixes
so less oxygen reaches the body

Question 8

Explain how pancreatic cancer can cause a person to lose weight(4)

Answer 8

> no enzyme production
so food isn’t fully digested
chemotherapy causes nausea
so less intake of food