Biology Paper 1

Front 1

Name the 5 animal cell structures and function.

Back 1

Nucleus - genetic material and controls cell.

Cytoplasm - a gel where most chemical reactions take place.

Cell membrane - holds cell together and controls what enters and leaves cell.

Mitochondria - where most reactions for aerobic respiration occur.

Ribosomes - where proteins are synthesised.

Front 2

Name the three cell structures plant cells have but animal cells don't.

Back 2

Rigid cell wall - cellulose and supports the cell since plants have no skeletal system.

Permenant vacuole - cell sap, a weak sugar salt solution.

Chloroplasts - where photosynthesis occurs which synthesises sugars for the plant. Chlorophyll is found here and is a green substance, which absorbs light for photosynthesis.

Front 3

Give the magnification equation.

Back 3

Magnification = image size / actual size

NOTE: Pay attention to units

Front 4

Name the definition for diffusion.

Back 4

Diffusion is the spreading out of particles from an area of high concentration to an area of low concentration.

Front 5

Define osmosis.

Back 5

Osmosis is the movement of water molecules across a semi permeable membrane from a region of high water concentration to a region of lower water concentration.

Front 6

True or false: bacteria have smaller surface area compared to their volume than multicellular organisms have.

Back 6

This is false, in single celled organisms gases and dissolved substances can diffuse directly into or out of their cell membrane since their surface area is large compared to their volume, so enough substances can be exchanged across the membrane to satisfy the cell.

Front 7

Name two human exchange surfaces and explain their features.

Back 7

The lungs contain millions of alveoli where gas exchange occurs (they have enormous surface area, moist lining, thin walls one cell thick and a good blood supply to maintain the concentration gradient). Another example is villi in the small intestine with a single layer of surface cells and a good blood supply.

Front 8

What is active transport?

Back 8

Substances that need to be absorbed against the concentration gradient (from a low to high concentration). It requires energy.

Front 9

Define differentiation.

Back 9

It is the process by which a cell becomes specialised for it's job.

Front 10

Give three specialised cells and their function.

Back 10

Some examples are: sperm cells for reproduction; nerve cells for rapid signalling; muscle cells for contraction; root hair cells for absorbing water and minerals and phloem and xylem tunes for transporting substances.

Front 11

Give the 5 steps of cell division of an animal cell.

Back 11

1) Before dividing, the cell needs to grow and increase the amount of subcellular structures such as ribosomes and mitochondria.

2) It then duplicates it's DNA into X shaped chromosome where each arm is the exact same as the other.

3) The cell is now ready for mitosis, the chromosomes line up at the centre of the cell and cell fibres pull them apart. The two arms of each chromosome go opposite ends of the cell.

4) Membranes form around each of the sets of chromosomes. These become the nuclei of the two new cells, the nucleus has now divided.

5) Lastly, the cytoplasm and cell membrane divide.

Front 12

Give the 4 steps of prokaryotic division through binary fission.

Back 12

1) The circular DNA and plasmids replicate

2) The cell gets bigger and the circular DNA strands move opposite ends of the cell.

3) The cytoplasm begins to divide and new cell walls begin to form.

4) The cytoplasm divides and two daughter cells are produced. Each daughter cell will have one copy of the circular DNA, but variable plasmid copies.

Front 13

What type of cell can embryonic stem cells turn into?

Back 13

Any type of cell! These are called undifferentiated cells and can differentiate into any other cell depending on the instructions given to the cell.

Front 14

Give a for and against argument for stem cell research.

Back 14

Against: people feel that each embryo is a potential human life.

For: curing existing patients that are suffering us more important than embryo rights.

Front 15

Where are stem cells found in plants?

Back 15

In the meristem, they can be used to grow crops of identical plants.

Front 16

Name the 4 steps of a multicellular organism's cell organisation.

Back 16

Similar cells are organised into tissues, which are organised into organs, which are organised into organ systems.

Front 17

What is an enzyme?

Back 17

An enzyme is a catalyst which has an active site which a certain substrate can be fit into and catalysed. This can be shown using the lock and key model.

Front 18

How can the rate of reaction be calculated?

Back 18

Rate = 1000 / time

Front 19

Name the 4 enzymes and their function.

Back 19

Amylase - breaks down starch.

Protease - converts protein to amino acids.

Lipase - converts lipids to glycerol and fatty acids.

Bile - neutralises stomach acid and emulsifies fats.

Front 20

Name the 4 food tests and what happens in the case of a positive result.

Back 20

Benedict's test - sugars. A positive test will turn green, yellow or brick red.

Iodine solution - starch. A positive result will cause the solution to change from orange to deep blue to black.

Biuret test - protein. A positive test will change from blue to pink or purple.

Sudan III test - lipid. A positive result will be indicated by a layer of red on the top of the test tube.

Front 21

Draw or recall a labelled diagram of the lungs.

Back 21

Front 22

Name the four chambers of the heart.

Back 22

Right and left atrium (top of the heart with the right on the left and the left on the right) and the right and left ventricle (on the bottom, but again reversed).

Front 23

Name the three blood vessels.

Back 23

Arteries - high pressure and carry blood away from the heart.

Capillaries - very thin and involved in the exchange of materials at the tissues.

Veins - carry blood to the heart, relatively low pressure and may contain valves to prevent the backflow of blood.

Front 24

True or false: arteries have strong walls and veins have relitively thinner walls.

Back 24

That is true: arteries require thicker walls to cope with the blood pressure. Capillaries, by the way, have walls one cell thick with permeable walls.

Front 25

Give the 4 components of blood and the functions.

Back 25

Red blood cells - have a biconcave disc shape to give a large surface area with haemoglobin which has a high affinity for oxygen. They have no nucleus.

White blood cells - defend against infection. They have a nucleus and phagocytes 'gobble up ' microorganisms and lymphocytes produce antibodies to fight microorganisms.

Platelets - help blood clot. These are small fragments of cells that have no nucleus and clot wounds to stop blood from getting out and microbes getting in.

Plasma - carries everything and dissolves carbon dioxide, glucose, amino acids, hormones, etc.

Front 26

What is the function of stents?

Back 26

They are tunes that are inserted into arteries and keep them open to prevent a heart attack for sufferers of coronary heart disease. They are effective for a long time and the recovery time from surgery is quick, however the complications from the operation and the risk of infection need to be considered.

Front 27

Give the function of statins.

Back 27

They are drugs to reduce the amount of bad LDL cholesterol which can cause fatty deposits in arteries which can lead to coronary heart disease.

Front 28

Give an advantage and disadvantage for statins.

Back 28

One advantage is that they reduce bad cholesterol, but are long term and can lead to negative side effects.

Front 29

Name two more ways of combating cardiovascular disease.

Back 29

Artificial heart and artificial blood can be also used (more often in an emergency).

Front 30

Give 3 factors that can affect health.

Back 30

The diet can lead to ill health, as can stress and life situation (access to medicines and contraception).

Front 31

What is a disease risk factor?

Back 31

They are linked to an increase of the chance of a person developing a certain disease in their lifetime. No guarantee that the person will get the disease.

Front 32

Name some direct risk factors for diseases.

Back 32

Smoking - can cause heart disease, lung disease, etc.

Obesity - can directly cause type 2 diabetes

Alcohol - if in excess is shown to cause liver disease.

UV radiation - can cause skin cancer.

NOTE: correlation doesn't always equate to cause.

Front 33

What is cancer caused by?

Back 33

It is caused by an uncontrolled growth of cells.

Front 34

Name the two types of cancer.

Back 34

Benign - where the tumour grows until no more room. Usually not safe and not cancerous.

Malignant - where a tumour grows and spreads to neighbouring healthy tissues using the bloodstream and can cause secondary tumours. Dangerous and cancerous, and can be fatal.

Front 35

Draw or recall the features of a cross section of a leaf.

Back 35

Front 36

What do phloem tubes transport?

Back 36

They transport foods like sugars and the transport goes in both directions. It is called translocation.

Front 37

What do xylem tubes transport?

Back 37

They transport water and mineral ions up and are made of dead cells joined end to end and strengthened with a material called lignin. They move water from the roots and out of the leaves - the transportation stream.

Front 38

What are guard cells adapted to do?

Back 38

Open and close stomara. They are used to control water loss.

Front 39

What 4 things affect transportation rate?

Back 39

Light intensity - since stomara close as it gets darker.

Temperature - the warmer it is, the faster the water particles can escape the leaf.

Air flow - A good air flow gives a strong diffusion gradient for the water to evaporate away.

Humidity - the dryer, the faster transpiration occurs. If the air is humid, the air is already got water in it and there is a smaller concentration gradient than if it was dry.

Front 40

True or false: viruses are cells.

Back 40

Viruses aren't cells. They are much smaller and are technically a protein.

Front 41

How does a bacterial infection make you feel ill?

Back 41

They produce toxins which damage cells and tissues.

Front 42

Give three ways pathogens can spread.

Back 42

Water - by drinking or bathing in dirty water (e.g. cholera).

Air - carried by the air in droplets when someone coughs or sneezes (e.g. influenza, measles)

Direct contact - by touching contaminated surfaces, even skin (e.g. athletes foot).

Front 43

Give information about measles.

Back 43

It is a viral disease spread by droplets from an infected person's sneeze or cough. It includes a red skin rash and can be fatal if not treated due to the complications such as pneumonia. Most people are vaccinated from a young age.

Front 44

Give information about HIV.

Back 44

It is an STI and can be spread by blood to blood contact. The virus attacks immune cells and can lead to AIDS.

Front 45

Give information about TMV.

Back 45

Tobacco mosaic virus affects plants and leaves become discoloured. This means the plant can't carry out photosynthesis as well and can affect growth.

Front 46

Give information about RBS.

Back 46

Rose black spot is a fungus which causes purple or black spots go appear on rose plants. The leaves turn yellow and fall off. Photosynthesis is affected and growth may not happen as well and is spread by water or wind. Gardeners can treat it by stripping the plant of affected leaves and applying fungicide. The leaves need to be destroyed to prevent other plants getting the disease.

Front 47

Give information about malaria.

Back 47

Malaria is caused by a protist and is spread by the anopheles mosquito (the vector). It causes fever and the spread of malaria can be prevented by stopping mosquitos from breeding and using insecticides and mosquito nets.

Front 48

Give information about salmonella.

Back 48

It is a type of bacteria that can cause food poisoning. Infected people can suffer from fever, vomiting, etc and is caused by the toxins that the bacteria produce. In the UK most chickens are vaccinated from salmonella.

Front 49

Give information about Gonorrhoea.

Back 49

It is an STI that is transmitted through unprotected sex. It is a bacteria and can cause urination pain and thicc discharge from the genitals. Antibiotics can treat gonorrhoea so long as it isn't resistant (super gonorrhoea).

Front 50

Give 4 ways to reduce disease.

Back 50

Being hygienic - washing hands, for example.

Destroying vectors - getting rid of organisms that spread disease (e.g. killing mosquitos).

Isolating individuals - if a person with a communicable disease is isolated it prevents them from passing it on.

Vaccination - This protects people from communicable diseases and means that they cannot develop the infection and pass it on.

Front 51

State ways that the body prevents pathogens getting into the body.

Back 51

The skin.

Hair/cillia and mucus in the nose and bronchi.

Hydrochloric acid in the stomach.

Front 52

How do vaccinations work?

Back 52

The vaccine injects small amounts of dead or inactive pathogens. These carry antigens which cause the body to produce antibodies to attack them even though the pathogen is harmless. If the pathogens of the same type occur after that, the white blood cells can rapidly produce antibodies to kill the pathogen.

Front 53

Give a pro and a con for vaccines.

Back 53

One pro is that hard immunity can eradicate diseases like smallpox and polio infections have fallen by 99%. However rare allergic reactions can occur and the vaccine doesn't always work.

Front 54

How can bacterial resistance be reduced?

Back 54

By the proper prescription of antibiotics, finishing the course of antibiotics, responsible farming etc.

Front 55

Where is aspirin and digitalis derived from?

Back 55

Aspirin is developed from a chemical in willow and digitalis is developed from a chemical in foxgloves.

Front 56

What is the difference between a blind and double blind trial?

Back 56

In a blind trial, the patient does not know whether they have been given the placebo, or "control pill", or not. In a double blind trial, neither the doctor or the patient knows.

Front 57

What is an optimum dose?

Back 57

The most effective amount of drug with the fewest side effects.

Front 58

What is peer review?

Back 58

Where external bodies test the results before they are published to prevent false claims.

Front 59

Name the three main steps in drug development.

Back 59

Preclinical testing (tested on human cells and tissues in the lab), animal testing (a UK legal requirement) and then human volunteers in a clinical trial.

Front 60

Draw or recall a diagram of how monoclonal antibodies can be developed.

Back 60

Front 61

Draw or recall how pregnancy tests work.

Back 61

Front 62

How can monoclonal antibodies be used to treat disease?

Back 62

Different cells have different antigens on their surface so you can make monoclonal antibodies that will just bind to, for example, liver cells. Cancer cells have tumour marker and monoclonal antibodies can be used to bind to only tumour cells and just kill the tumour cells.

Front 63

Name some cons of monoclonal antibodies.

Back 63

They can induce unexpected side effects like vomiting and aren't as widely used as previously thought.

Front 64

What are nitrates in plants used for?

Back 64

Making proteins for growth.

Front 65

What are magnesium ions in plants used for?

Back 65

Making chlorophyll, which is needed for photosynthesis. Without it, the plants can suffer from chlorosis and yellow leaves.

Front 66

Name the three types of defences plants have against pathogens.

Back 66

Physical - waxy cuticle, etc

Chemical - antibacterial chemicals, etc

Mechanical - thorns to stop animals, etc