Organisation

Question 1

The five levels of organisation

Answer 1

cells, tissues, organs, organ systems, organisms

Question 2

Small intestine
what does it have + why

Answer 2

villi for large surface area
lots of capillaries supplying villi for good blood supply
short diffusion distance

Question 3

Path of food

Answer 3

mouth, oesophagus, stomach, small intestine, large intestine, rectum, anus

Question 4

Where enzymes are:
amylase-
protease-
lipase-
whats in liver+ what does it do
whats in gall bladder

Answer 4

amylase- salivary glands + pancrease
protease- stomach + pancreas
Lipase- pancreas
Liver- bile which speeds up enzyme action
gall bladder- stores bile before its released into small intestine

Question 5

how enzymes work

Answer 5

the substrate binds to the active site and the enzyme catalyses the reaction

Question 6

Factors affecting enzymes

Answer 6

temp= to far above optimum temp will denature it
pH= too far above or below optimum pH will denature it

Question 7

Bile

Answer 7

enzymes in the pancreas + small intestine work best in alkaline conditions, so bile is alkaline, therefore it neutralises HCL in stomach

it also helps to digest fats= emulsifies them to form smaller droplets which increases SA for eznymes to act on

Question 8

What do the enzymes work on and what are they made of?

Answer 8

AMYLASE: works on carbohydrates (starch), made from simple sugars e.g. glucose
PROTEASE: works on proteins, made from amino acids
LIPASE: works on lipids (fats + oils), made from fatty acids and glycerol

Question 9

Where are the enzymes produced and where are their sites of action?

Answer 9

AMYLASE: produced in salivary glands + pancreas, site of action is small intestine + mouth
PROTEASE: produced in pancreas, stomach + small intestine, site of action is small intestine + stomach
LIPASE: produced in pancreas + small intestine, site of action is small intestine

Question 10

Components of blood + function

Answer 10

plasma= transports blood cells + chemicals around the body, straw coloured liquid
platelets= helps blood clot, smaller than red/ white blood cells
white blood cells= protects body against infection, has a nucleus, larger than red blood cell
red blood cells = carries oxygen around to body’s cells. has haemoglobin which is a pigment that binds to oxygen

Question 11

How are red blood cells specialised for their function?

Answer 11

no nucleus= more space for haemoglobin
bioconcave= more surface area for oxygen

Question 12

What are the three blood vessels like + what are they for?

Answer 12

Arteries= carry blood away from the heart, high pressure, thick muscular walls + small lumen (keeps high pressure)
Veins= carry blood towards the heart, large lumen (keeps low pressure), has valves to prevent back-flow of blood
Capillaries= brings blood to cells of body, subsrances diffuse in/ out of the blood, walls only one cell thick so short diffusion path

Question 13

Path of oxygen through lungs + other parts of lungs

Answer 13

Mouth + nose- trachea- bronchus- bronchioles- alveoli
Other: ribs, intercostal muscle, diaphragm

Question 14

Alveoli

Answer 14

good blood supply, CO2 diffuses in O2 diffuses out, maintains a steep conc gradient, walls are one cell thick so short diffusion path, large SA to volume ratio

Question 15

what do gills do in fish?

Answer 15

1. large SA
2. good blood supply
3. one cell thick= faster diffusion
4. ventilated
5. counter-current (water ans blood go opposite ways which maintains steep conc gradient)

Question 16

path of blood through the heart

Answer 16

vena cava- right atrium- right ventricle- pulmonary artery- lungs- pulmonary vein- left atrium- left ventricle- aorta- body

Question 17

Which side is thicker and why?
where are the pacemaker cells?

Answer 17

left side is thicker to pump blood under high pressure
pacemaker cells are in right atrium

Question 18

Coronary heart disease

Answer 18

coronary arteries supply the heart
fatty deposits create plaque which hardens + narrows arteries, therefore restricting blood flow to heart
To fix it: stent or statins

Question 19

How Stents + Statins work, downsides

Answer 19

Stents: catheter inserted, balloon inflated, catheter removed, risk of clotting
Statins: lowers blood cholesterol levels, slows buildup of fatty deposits, slower to take effect + you have to remember to take them

Question 20

what happens when you have faulty valves + treatment

Answer 20

blood flows in both directions so less blood reaches the body= can cause death
mechanical valves= last forever but have to take medication
biological valved= no medication but only last 10-15 years,

Question 21

What does an artificial pacemaker do?

Answer 21

sends electrical signals to the heart to stimulate it to beat correctly

Question 22

Heart failure- solutions

Answer 22

Artificial heart= keeps patient alive while a donor is found, less likely to be rejected but can cause clots so you have to take blood thinners, lots of machinery involved (can’t leave hospital)
natural heart= lower risk of clotting + can live a normal life BUT risk of rejection

Question 23

3 vague factors that affect health
and 4 in detail ones

Answer 23

diet, stress, life situation (clean water? etc)
1) defects in immune system increases risk of infectious dieases
2) viruses living in body cells can trigger cancers
3) immune reactions caused by a pathogen can trigger allergies
4) physical ill health can cause depression/ other mental illnesses

Question 24

Causal mechanisms of:
cardiovascular diease
type 2 diabetes
liver + brain damage
lung cancer + disease
damage to foetus
cancer

Answer 24

Cardiovascular disease- diet, smoking, lack of exercise
type 2 diabetes- obesity= body stops responding to high levels of glucose
liver + brain damage- alcohol= liver cancer + cirrhosis, brain stops functioning
lung cancer + disease- smoking= tar is carcinogen, turns lungs grey
damage to foetus- smoking + alcohol= low birth weight, premature/ still births
cancer- ionising radiation etc

Question 25

Carcinogen def
what is cancer?

Answer 25

carcinogen- a chemical or other agent that can cause cancer
Cancer- when changes in a cell cause abnormal or uncontrolled cell growth + division= leads to formation of tumours

Question 26

Two types of cancer

Answer 26

Benign- 1 area, doesn’t spread but can put pressue on organs so stilll dangerous
Malignant- spreads to other parts, parts break off and spread in blood so can cause secondary tumours

Question 27

Two treatments for cancer

Answer 27

Radiotherapy- uses radiation to kill cancer cells, can harm healthy cells too
Chemotherapy- uses chemicals to halt mitosis of rapidly dividing cells (so cancer but also hair)

Question 28

which two types of cancer depend on genetics?

Answer 28

breast + ovarian

Question 29

Functions of the parts of the leaf

Answer 29

Upper and lower epidermis- waxy cuticle, protects, thin so light can penetrate
palisade mesophyll- photosynthesis, lots of chloroplasts, tightly packed
spongy mesophyll- gas exchange + diffusion is easy, air space for gases
guard cell- fills with water so either turgid or flaccid
stomata- pores which open and close according to guard cells

Question 30

xylem + phloem function

Answer 30

xylem- transports water + mineral ions, upwards only, non- physical process
phloem- dissolved food (glucose up + down the okant, energy needed)

Question 31

what happens in transpiration?

Answer 31

water evaporates from surface of cells in spongy mesophyll, the water vapour then leaves through stomata
water is then pulled up through xylem from roots to replace the lost water

Question 32

Factors that affect the rate of transpiration

Answer 32

temp, light intensity, humidity (if in dryer conditions, there is a steeper conc gradient so diffusion is easier and therefore transpiration is too), air movement ( if windier, steeper conc gradient so more evaporation + transpiration)

Question 33

Preventing water loss

Answer 33

1. thick waxy cuticle= waterproofs leaf
2. wilting= reduces SA for transpiration, less direct sunlight
3. close stomata (drastic)= stops water loss + photosynthesis