End Of Year Exams Flashcards
1
Q
What is a variable?
A
A variable is a factor of an experiment that can be measured and changed
2
Q
What is an independent variable? Give examples
A
The variable that is being changed during the experiment
a) Age
b) Time slept
3
Q
What is a dependent variable? Give examples
A
The variable being tested or measured during the experiment
a) Health
b) Test score
4
Q
What is a control variable? Give examples
A
A control variable is anything that is held constant or limited in a research study. It is important because it could have an effect on the experiment, although it is not the independent or dependent variable.
- Temperature
5
Q
What is accuracy in an experiment? How do you find out if an experiment is accurate?
A
Accuracy is how close a measurement is to its true value. Finding out the mean of results, without outliers, helps you find out if results are accurate.
6
Q
What is precision in an experiment?
A
Precision is how close repeat measurements are.
7
Q
What is validity in an experiment?
A
The conclusions that can be drawn from the experiment are valid if the method makes sure that the effects observed and measured are due to the cause claimed.
8
Q
How to calculate the total magnification?
A
Magnification of the microscope = magnification of eyepiece × magnification of objective
9
Q
How to calculate magnification?
A
Size of image = Real size of object * Magnification
10
Q
What is 1mm equivalent to, using a smaller unit of measure?
A
1000um (micrometres)
11
Q
What is 1um equivalent to, using a smaller unit of measure?
A
1000nm (nanometres)
12
Q
What is 1nm equivalent to, using a smaller unit of measure?
A
1000pm (picometres)
13
Q
What are the three components of health>
A
Social wellbeing
Physical wellbeing
Mental wellbeing
14
Q
What is a communicable disease
A
A disease caused by pathogens and is infectious
15
Q
What is a non communicable disease
A
A disease that isn’t caused by pathogens and isn’t infectious
16
Q
What is a positive correlation
A
When one variable increases as the other variable increases, or when one variable decreases as the other variable decreases
17
Q
What is a negative correlation
A
When one variable decreases as the other increases
18
Q
What are the causes of non communicable diseases
A
- Mutations in genes
- Lifestyle
19
Q
Give examples malnutrition
A
- Eating too little of particular nutrients can cause deficiency diseases
- Eating foods with too much fat and sodium can lead to obesity
20
Q
How to calculate BMI
A
mass/height^2
21
Q
How to calculate waist:hip
A
waist/hip. A ratio over 1 means obesity
22
Q
What are ways to treat cardiovascular disease
A
Stents
Coronary artery bypass surgery
Heart transplants
23
Q
What are the advantages of stent surgery
A
-Long term effect of maintaining proper blood flow in a blood vessel
-Reduction of the risk of stroke
-Improvement of organ function, including the kidneys
-Life-saving option during a heart attack
24
Q
What are the disadvantages of stent surgery
A
-Allergic reaction to stent material
-Blood clot formation on the stent
-Procedure related issues including damage to blood vessels
-The blood vessel may collapse
25
What are the advantages of bypass surgery
- Having less chest pain, or having your chest pain go away
- Lowering your chance of a heart attack
- Lower risk of stroke
26
What are the disadvantages of bypass surgery
-Bleeding.
-Death.
-Heart attack due to a blood clot after surgery.
-Infection at the site of the chest wound.
27
What are the advantages of heart transplant
- Whole new heart
- Longer life
28
What are the disadvantages of heart transplant
- Organ rejection.
- Infections (because of immune system suppression).
- Kidney disease and kidney failure.
- High blood pressure (hypertension).
29
What is diffusion
A net movement of liquid or gas particles from a high concentration to a low concentration
30
What is a concentration gradient
The difference between the low and high concentrations
31
How do certain factors affect the rate of diffusion
Concentration gradient- The greater the difference in concentration, the quicker the rate of diffusion
Temperature - The higher the temperature, the more kinetic energy the particles will have, so they will move and mix more quickly
Surface area of the cell membrane separating different regions - The greater the surface area, the faster the rate of diffusion
32
How is the cytoplasm adapted to its function
It provides shape to the cell
It is where many chemical reactions take place
33
How is the nucleus adapted to its function
Contains genetic material, including DNA, which controls the cell's activities.
34
How is the cell membrane adapted to its function
It is permeable to some substances but not to others and so controls the movement of substances in and out of the cell.
35
How is the mitochondrion adapted to its function
Organelles that contains the enzymes for respiration, and where most energy is released in respiration.
36
How is the ribosome adapted to its function
Tiny structures where protein synthesis occurs.
37
How is the chloroplast adapted to its function
Organelle that contains the green pigment, chlorophyll, which absorbs light energy for photosynthesis. Contains the enzymes needed for photosynthesis.
38
How is the cell wall adapted to its function
Plant and bacterial cell walls provide structure and protection. Only plant cell walls are made from cellulose.
39
How is the vacuole adapted to its function
Filled with cell sap to help keep the cell swollen.
40
How is chromosomal DNA adapted its function
The DNA of bacterial cells is found loose in the cytoplasm. It is called chromosomal DNA and is not contained within a nucleus.
41
How is plasmid DNA adapted to its function
Bacteria also have small, closed-circles of DNA called plasmids present in their cytoplasm. Unlike the chromosomal DNA, plasmid DNA can move from one bacterium to another giving variation.
42
How is the flagellum adapted to its function
Bacteria can have one or more flagella (singular: flagellum). These can rotate or move in a whip-like motion to move the bacterium.
43
How is the cell wall adapted to its function
Plant and bacterial cell walls provide structure and protection. Only plant cell walls are made from cellulose.
44
How is the head of a sperm adapted to its function
The head contains the genetic material for fertilisation in a haploid nucleus. The acrosome in the head contains enzymes so that a sperm can penetrate an egg.
45
How is the middle part of a sperm adapted to its function
The middle piece is packed with mitochondria to release energy needed to swim and fertilise the egg.
46
How is the tail of a sperm adapted to its function
The tail enables the sperm to swim. Sperm are the smallest cells in the body and millions of them are made.
47
How is the cytoplasm of an egg adapted to its function
The cytoplasm contains nutrients for the growth of the early embryo.
48
How is the haploid nucleus of the egg adapted to its function
The haploid nucleus contains the genetic material for fertilisation.
49
How is the cell membrane adapted to its function
The cell membrane changes after fertilisation by a single sperm so that no more sperm can enter.
50
How are ciliated epithelial cells adapted to their function
Cilia on the surface beat to move fluids and particles up the trachea.
51
What are enzymes
Enzymes are proteins that speed up biological reactions without being used up, which is why they are biological catalysts. There are involved in most chemical reactions, such as photosynthesis, protein synthesis,etc.
52
How are enzymes adapted to their function
Each enzyme has a unique shape. This allows the active site to be perfectly matched and attached to a very specific substrate that has the same shape as the active site.
53
How does the enzyme help with chemical reactions
The substrate is matched with the active site to create and enzyme-substrate complex, so then the enzyme releases products.
54
How does an enzyme become denatured
High temperature and pH that is too low or too high, denatures an enzyme, because the substrate can no longer fit into the active site.
55
How are arteries adapted to their function?
Arteries carry blood away from the heart straight after it has been pumped. This means it is under high pressure. The walls of arteries are made of thick muscle to withstand this pressure. This muscle is also elastic to allow a pulse of blood to travel along when your heart beats. There is a smaller lumen to help blood flow throughout the whole body faster.
56
How are veins adapted to their function?
Veins carry blood back to the heart. This blood is under lower pressure because some of it has been lost as it travelled around your body. The walls of veins are made of thinner muscle and are less elastic than arteries. Because the blood is under lower pressure, one-way valves in your veins stop it flowing backwards. They have a large lumen to make space for the valves.
57
How are capillaries adapted to their function?
Capillaries are the tiny blood vessels that branch out into every tissue in your body carrying substances your cells need like oxygen and glucose for respiration and for removing waste products like carbon dioxide. They have very thin walls to allow these substances to move by diffusion in and out of your cells. Capillaries join your arteries to your veins. Walls are made of semi-permeable membrane to allow transport of gases and nutrients into and out of the blood
58
How are red blood cells adapted to their function?
No nucleus to allow more room for haemoglobin. Haemoglobin to bid with oxygen (oxyhaemoglobin- bright red) so it can be transported. Biconcave to create large surface area to maximise diffusion. They are small and flexible so that they can fit through narrow blood capillaries. They are thin, so there is only a short distance for the oxygen to diffuse to reach the centre of the cell.
59
How are phagocytes adapted to their function?
Phagocytes change shape to engulf microbes and then digest them
60
How are lymphocytes adapted to their function?
Lymphocytes produce antibodies that attach to microbes and destroy them
61
How are platelets adapted to their function?
Platelets change shape to gather around cuts and injuries and produce tiny fibres that trap red blood cells and form a scab, so the person doesn't bleed to death.
62
What does the heart look like?
https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.britannica.com%2Fscience%2Fheart&psig=AOvVaw12N8DvZh3TGmgDG8XJlHGk&ust=1685883810528000&source=images&cd=vfe&ved=0CBAQjRxqFwoTCOD8oN-Up_8CFQAAAAAdAAAAABAJ
https://bam.files.bbci.co.uk/bam/live/content/zgdwkty/large
Right ventricle ----> Pulmonary artery ----> Pulmonary vein ----> Left ventricle -----> Aorta -----> Vena cava ----> Right ventricle
63
What is coronary circulation?
The heart also needs its own blood vessels- coronary arteries and cardiac veins. They supply the heart muscle with oxygen so that the muscle cells can respire, and remove waste carbon dioxide.
64
What are the stages of medical drug testing
Preclinical drug testing
Animal trials
Human clinical trials
65
What happens during preclinical drug testing?
The drugs are tested using computer models and human cells grown in the laboratory. This allows the efficacy and possible side effects to be tested. Many substances fail this test because they damage cells or do not seem to work.
66
What happens during animal trials?
Drugs that pass the first stage are tested on animals. In the UK, new medicines have to undergo these tests. But it is illegal to test cosmetics and tobacco products on animals. A typical test involves giving a known amount of the substance to the animals, then monitoring them carefully for any side-effects.
67
What happens during human clinical trials?
Drugs that have passed animal tests are used in clinical trials. They are tested on healthy volunteers to check that they are safe. The substances are then tested on people with the illness to ensure that they are safe and that they work. Low doses of the drug are used initially, and if this is safe the dosage increases until the optimum dosage is identified.
68
What are 3 key factors that drugs are checked for, and why?
Safety - This is important as some drugs are toxic, and have other side effects that might be harmful to people.
Effectiveness - This is also known as efficacy, and checks how well the drug cures the disease, or improves symptoms.
Dosage - This varies, and has to closely controlled, as too high a concentration might be toxic.
69
What are the four types of pathogens?
Virus
Bacteria
Fungi
Protists
70
What are the 5 types of transmission of pathogens?
Direct contact
Water
Air
Unhygienic food preparation
Vector
71
What is HIV?
HIV causes:
- Mild flu-like symptoms
- AIDS (infection starts to attack immune system)
How it is spread:
- Sexual contact
- Sharing a drug needle with a HIV carrier
- Cuts
How to prevent infection:
- Anti viral drugs
72
What is cholera?
What it causes:
- Diarrhoea
- Dehydration
How it is spread:
- Contaminated water
How to prevent infection:
- Drinking and cooking with cleaning water
- Boiling infected water to kill bacteria
73
What is tuberculosis?
What it causes:
- Fever
- Coughing up blood
- Weight loss
How it is spread:
- Airbourne, sneezing coughing droplets
How to prevent infection:
- Isolation
74
What is chalara ash dieback?
What it causes:
- Bark lesions in trees
- Leaf loss
How it is spread:
- Airbourne, from infected trees
How to prevent infection:
- Cutting infected trees
- Burning infected trees
75
What is malaria?
What it causes:
- Fatal kidney and brain damage
How it is spread:
- By animals and insects
How to prevent infection:
- Using insecticide
- Mosquito net
76
What are phagocytes?
The phagocytes' membrane surrounds the pathogen and the enzymes found inside the cell, then break down the pathogen in order to destroy it. As phagocytes do this to all pathogens that they encounter, we call them 'non-specific'.
77
What are lymphocytes?
Lymphocytes detect that both the proteins and pathogens are foreign, not naturally occurring within your body and produce antibodies. The antibodies created by the lymphocytes cause pathogens to stick together, and make it easier for phagocytes to engulf them.
Some pathogens produce toxins which make you feel ill. Lymphocytes can also produce antitoxins to neutralise these toxins. Both the antibodies and antitoxins are highly specific to the antigen on the pathogen, thus the lymphocytes that produce them are called 'specific'.
78
What are memory lymphocytes?
A specific type of lymphocyte called a memory lymphocyte can 'remember' the antigens from an infection by a previous pathogen. A second exposure to it will result in a much faster immune response. Antibodies will be produced much faster, which often stops us becoming ill again. There are hundreds of common colds caused by different viruses.
79
What happens during the primary infection compared to the secondary infection?
First infection, the lymphocytes recognise the antigens on the pathogen, produce a clone of plasma cells and memory cells
Plasma clone cells produce antibodies which kill the pathogen, these only survive for a few weeks
Second infection, the memory cells recognise the antigen and rapidly produce many plasma clone cells which produce vast numbers of antibodies so that the person becomes immune to the disease.
80
Describe how vaccination provides protection against disease
When the vaccination is injected into the blood, the weakened pathogens will stimulate a primary response of white blood cells, by injecting dead, weakened pathogens. These white blood cells would destroy the pathogens and produce plasma and memory cells. During the first infection, this will trigger a secondary response of memory cells that produce antibodies, which are made at a more rapid rate and higher production than the primary response.
