Put the following in size order from smallest to largest:
organ, cell, organ system, tissue
cell → tissue → organ → organ system
What is a tissue?
A group of cells with a similar structure and function.
What is an organ?
Groups of tissues forming particular functions.
What is the function of the digestive system?
To digest and absorb food
What do enzymes do?
Catalyse (speed up) reactions
Name the part of the enzyme indicated by the arrow
How does the ‘lock and key’ model explain how enzymes work?
'Lock and key' is a simple model to explain that each enzyme has an active site of a specific shape to fit a specific substrate (just like a specific key is needed to fit a lock).
1. Where is amylase produced?
2. Where does amylase work?
3. What does amylase breakdown and what are the products?
1. Amylase is produced in the salivary glands, small intestine and pancreas.
2. Amylase works in the mouth and small intestine.
3. Amylase breaks down starch into sugar.
1. Where is protease produced?
2. Where does protease work?
3. What does protease breakdown and what are the products?
1. Protease is produced in the stomach, small intestine and pancreas
2. Protease works in the stomach and small intestine
3. Protease breaks down protein into amino acids
1. Where is lipase produced?
2. Where does lipase work?
3. What does lipase breakdown and what are the products?
1. Lipase is produced in the small intestine and pancreas
2. Lipase works in the small intestine
3. Lipase breaks down lipids (fats) into fatty acids and glycerol.
What do digestive enzymes do?
Break down food into soluble molecules that can be absorbed into the bloodstream.
Name the enzyme that is a type of carbohydrase.
What are the products of digestion used for?
• To build new carbohydrates, lipids and proteins.
• Some glucose is also used for respiration.
1. Where is bile made?
2. Where is bile stored?
3. What two things does bile do?
1. Bile is made in the liver.
2. Bile is stored in the gallbladder.
3. • Bile is alkaline so neutralises the hydrochloric acid from the stomach
• It emulsifies fat to form small droplets which increases the surface area to increase the rate of fat breakdown.
Name the four chambers of the heart.
Name the four major blood vessels of the heart.
Name the parts of the lungs in the diagram below.
Describe how the double circulatory system works.
Circulatory system made up of two circuits.
Circuit 1 – Right ventricle pumps deoxygenated blood to lungs. Oxygenated blood returns to the heart.
Circuit 2 – Left ventricle pumps oxygenated blood around the body. Deoxygenated blood returns to the heart.
Name the arteries that wrap around the heart, supplying it with oxygen.
What is coronary heart disease?
• A disease that is caused by fatty material build-up inside the coronary arteries.
• These arteries become narrower.
• This reduces blood flow to the heart.
• This results in a lack of oxygen to the heart muscle.
Describe the three ways in which the lungs are adapted for gas exchange.
• Thin, moist walls,
• Large surface area,
• Close network of capillaries
1. Name the cells that control the natural resting heart rate.
2. Where are these cells located?
3. If these cells are not working properly, what might a doctor suggest?
1. Pacemaker cells
2. Right atrium
3. Have an operation to insert an artificial pacemaker
Describe the structure and function of the three blood vessels in the body.
Arteries - Function: Carry blood away from the heart. Structure: Strong, thick, muscular, elastic walls because blood is at high pressure.
Veins - Function: Carry blood to the heart. Structure: Thinner walls because blood is at low pressure. Bigger lumen to help blood flow. Valves to stop blood flowing backwards.
Capillaries – Function: exchanging materials (e.g. oxygen and glucose) at the tissues Structure: Small lumen and thin, permeable walls.
Name the four major parts of the blood.
• Red blood cells
• White blood cell
Give the function of the following parts of the blood:
3. Red blood cells
4. White blood cells
1. Plasma – liquid that carries everything in the blood (e.g. urea, hormones, carbon dioxide e.t.c)
2. Red blood cells – transport oxygen
3. White blood cells – defend against disease
4. Platelets – help blood clot
How are the following parts of the blood adapted to carry out a specific function?
2. Red blood cells
3. White blood cells
1. Platelets – small cell fragments, no nucleus
2. Red blood cells – Biconcave shape, Large surface area, no nucleus
3. White blood cells – can change shape to engulf pathogens (phagocytosis). Some also produce antibodies and antitoxins.
How do red blood cells transport oxygen around the body?
• They contain a red pigment called haemoglobin
• Oxygen binds to haemoglobin to make oxyhaemoglobin
• Red blood cells travel in the blood, transporting oxygen to cells all around the body
1. Name the mechanical device that can be used to treat coronary heart disease.
2. Name the drugs that can be used to treat coronary heart disease.
1. Mechanical: Stent
2. Drugs: Statins
How do statins work?
• They reduce blood cholesterol levels
• Which slows down the rate of fatty material deposit.
What are the consequences of having a faulty heart valve?
• The heart doesn’t circulate blood as efficiently.
• Therefore heart has to work harder to deliver sufficient levels of oxygen and glucose around the body.
1. What are man-made replacement heart valves called?
2. What are replacement valves transplanted from humans or other animals called?
1. Mechanical valves
2. Biological valves
What is an artificial heart and what are they used for?
• Mechanical devices that pump blood around the body.
• They are fitted to people whose heart has failed and are waiting for a donor or to allow the heart to rest following injury or operation.
What is ‘Health’?
The state of physical and mental well being
Give two examples of when two different types of disease or ill health can interact.
Any two from:
• Immune system defects mean a person is more likely to suffer from infectious diseases.
• Viruses living in cells can trigger cancer
• Immune reactions initially caused by a pathogen can trigger allergies (e.g. skin rashes or asthma)
• Physical ill health can lead to depression and other mental health issues
What is epidemiology?
The study and analysis of the patterns, causes, and effects of health and disease in populations
1. What is a risk factor?
2. List two examples of risk factors.
1. Something that increases the likelihood of a person getting a disease
2. Examples include: Drinking alcohol, smoking, obesity, working with asbestos, exposure to high levels of air pollution, UV exposure, viral infection, inheriting faulty genes
How does illness affect the finances of:
a) An individual
b) A country
a) An ill person might not be able to work/may need time off work – income reduced.
b) High cost to NHS to treat patients, the national economy also affected if the patient isn’t working.
1. Why are incidences of obesity, Type 2 diabetes and cardiovascular disease higher in deprived areas?
2. Why are non-communicable diseases more common in developed countries?
1. People in deprived areas are more likely to smoke, have a poor diet and be less active.
2. People in developed countries generally have a higher income and often consume food containing higher fat levels then under-developed countries.
1. What is meant by a ‘communicable’ disease?
2. What is meant by a ‘non-communicable’ disease?
1. Communicable disease: Diseases that can be spread between people (or between animals and people)
2. Non-communicable disease: Diseases that cannot be spread between people (or between animals and people)
Give two examples of risk factors that have a proven link to a particular disease.
Any two from:
• The effects of diet, smoking and exercise on cardiovascular disease
• The effect of alcohol on brain and liver function
• The effect of smoking on lung disease and lung cancer
• Carcinogens, including ionising radiation, as a risk factor for cancer
• Obesity as a risk factor for Type 2 diabetes
Name the leaf tissues labelled on the diagram below:
Describe the function of the following plant tissues:
a) Meristem tissue
b) Epidermal tissue
c) Palisade mesophyll
d) Spongy mesophyll
e) Xylem and phloem
a) Meristem tissue: Cells can differentiate into different types of cells – essential for growth
b) Epidermal tissue: Covers the whole plant
c) Palisade mesophyll: Full of chloroplasts for photosynthesis
d) Spongy mesophyll: provides gaps for gases to diffuse for photosynthesis.
e) Xylem and phloem: Transport water (xylem) and food/sugar (phloem) around the plant
Is the 'leaf' a cell, tissue or organ?
Name the cells that surround the stomata
Describe the structure and function of the xylem.
Structure: Made of dead cells. Hollow tubes strengthened by lignin.
Function: Transport water and mineral ions from roots to leaves
Describe the structure and function of the phloem.
Structure: Columns of elongated cells with small pores in end walls that cell sap flows through.
Function: Transport dissolved sugars from the leaves to the rest of the plant Transport goes in both directions.
Explain the effects of the following conditions on the rate of transpiration:
c) Air movement
d) Light intensity
a) Temperature: The higher the temperature, the higher the rate of transpiration.
b) Humidity: The lower the humidity (drier) the higher the rate of transpiration.
c) Air movement: The greater the airflow around the plant, the higher the rate of transpiration.
d) Light intensity: The higher the light intensity, the higher the rate of transpiration.
What does ‘transpiration’ mean?
Transpiration is the loss of water from a plant
What three organs make up a plant’s organ system to transport substances around the plant?
What is translocation?
The movement of food molecules through phloem tissue
Describe how the guard cells open and close the stomata.
• When guard cells fill with water, the go plump and turgid and open.
• When guard cells lose water, they go flaccid and close the stomata
What is the transpiration stream?
The movement of water from the roots, through the xylem and out of the leaves.
Describe how you would use a Potometer to measure the rate of transpiration in plants
• Record starting position of air bubble
• Start the stopwatch and leave for quite a long time (e.g. 24 hours)
• Record distance bubble moves.
• Calculate the rate of transpiration by dividing distance bubble moved by time.
On what side of the leaf are most stomata found and why?
On the underside because it’s not exposed to sunlight so less water is lost.
What is cancer?
A result of changes in cells that lead to uncontrolled growth and division
What are benign tumours?
Growths of abnormal cells which are contained in one area, usually within a membrane. They do not invade other parts of the body.
What are malignant tumours?
Malignant tumours are cancers. They invade neighbouring tissues are spread to different parts of the body where they form secondary tumours.