What are the 7 main food groups?
Carbohydrates, Fats, Protein, Fibre, Vitamins, Minerals and Water
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What are the roles of Carbohydrates and Fats?
To release energy (Fats - to keep warm)
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What is the role of Protein?
For Growth, Cell repair and Cell replacement
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What is the role of Fibre?
To keep things running smoothly (prevents constipation)
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What are the the roles of Vitamins and Minerals?
To keep skin, bones and blood healthy
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What is the role of Water?
To stay hydrated
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What is your Metabolism?
All of your body's chemical reactions
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What is your Metabolic Rate?
The speed at which your body's chemical reactions occur
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What 2 factors can increase your Metabolic Rate?
1. Excercise 2. Higher Proportions of Muscle
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Why do physically bigger people have higher Metabolic Rates?
They have more cells and therefore require more energy
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What is Cholesterol?
A fatty substance that is transported by the blood
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What 2 factors can cause high cholesterol levels?
1. Diet (too much saturated fat) 2. Inherited factors
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What can high cholesterol levels lead to?
Diseases of the heart and blood vessels
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What causes Malnourishment?
When people's diets are badly out of balance (different from Starvation)
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What 4 health problems can arise from obesity?
1. Arthritis 2. Type 2 diabetes 3. High blood pressure 4. Heart disease
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What are 4 effects of Malnutrition?
1. Slow growth 2. Fatigue 3.Poor resistance to Infection 4. Irregular periods
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What causes Deficiency Diseases?
Lack of Vitamins or Minerals
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What can a lack of Vitamin C cause?
Scurvy - causes problems with the skin, joints and gums
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What are 3 advantages of excercise?
1. Increases the amount of energy 2. Decreases fat storages 3. Builds muscle (boosts Metabloc rate)
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What is an inherited factor that can affect Metabolic rate?
Underactive Thyroid glands - can lower metabolic rate and cause obesity
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What are Pathogens?
Microorganisms that enter the body and cause infectious diseases
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What are some examples of Pathogens?
Measles, Rubella, Malaria, Meningitis, Appendicitis, Cholera and Ebola
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What are Bacteria?
Very small cells which can reproduce rapidly inside the body
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How do Bacteria make you fell ill?
They damage your cells and produce Toxins
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How do Viruses make you feel ill?
They invade your cells and use the cells' machinery to replicate themselves. The cell bursts, releasing the new Viruses. This cell damage causes you to fell ill
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In what ways can we deal with Pathogens?
Washing hands, Vaccinations, Dissinfectant, Antibiotics
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What in the body's defence system stops microorganisms getting inside the body?
Skin, plus Hairs and Mucus in your repiratory tract
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What are Platelets and what do they do?
They are small fragments of cells which help blood clot quickly to seal wounds
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What are the 2 main white blood cells?
1. Phagocytes 2. Lymphocytes
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In what 3 ways do white blood cells deal with pathogens?
1. Engulfing & digesting them 2. Producing Antibodies 3. Producing Antitioxins
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What happens in Phagocytosis?
Phagocytes pick up chemical signals given off by bacteria. The membrane folds in to engulf the Bacteria. Digestive enzymes are added to kill and digest the bacteria. Harmless particles resulting from the digestion are released
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What do Lymphocytes produce?
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What does every invading cell have on it's surface?
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How do Antibodies work?
When Lymphocytes come across foreign Antigens, they produce Antibodies which attach to the Antigens and kill the cell
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What happens in terms of Antibodies when a person is infected with the same Pathogen again?
The Lymphocytes recognise the Antigens and produce anitbodies rapidly. So, the person is immune
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What is the role of Antitoxins?
They counter Toxins produced by Bacteria. This lessens the symptoms
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What is the Incubation period?
The delay between infection with a Pathogen and the development of symptoms
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What is in Vaccines?
Dead or inactive pathogens of a certain disease
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What are Memory cells for?
If someone is infected by the same pathogen again, the memory cells can produce antibodies rapidly and in large amounts
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What are 2 advantages of vaccination?
1. Vaccines have helped control diseases that were common 2. If a large percentage of the population are vaccinated, people are unlikely to catch disease because fewer people are able to pass it on
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What are 2 disadvantages of vaccination?
1. They don't always work 2. People can have bad reactions to them
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What is an Epidemic?
When disease is found in high numbers in one part of the world
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What is a Pandemic?
When disease is found in high numbers in several parts of the world
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What can Painkillers do and not do?
They can relieve symptoms but they cannot cure
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What are Antibiotics produced from?
Fungi and Bacteria
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How do Antibiotics kill Bacteria?
They damage cell walls
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What can Antibiotics only be used on?
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Why are Antibiotics useless on Viruses?
Because they reproduce inside human cells
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What causes bacteria to be Resistant?
Bacteria can mutate and these mutations cause them to be resisitant
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How do resistant bacteria strains increase?
When you treat an infection, only non resistant strains are killed. The resistant bacteria survive and reproduce so the population of the strain increases
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What is an example of an Antibiotic resisitant strain?
MRSA (resistant to Methicillin)
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How can we slow down the development of resistant strains of Bacteria?
Doctors must avoid over-prescribing antibiotics
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What culture medium can microorganisms be grown in and why is this effective?
Agar Jelly in a Petri dish which contains carbohydrates, minerals, proteins and vitamins which the bacteria need to grow
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What do we use to transfer the Bacteria?
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What happens if we do not sterilise equipment when growing bacteria?
Unwanted microorganisms grow and affect the results
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How do we sterilise Inoculating loops?
Pass them through a flame
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What temperature are petri dishes heated to and why?
25 degrees C becuase higher temperatures can cause the growth of dangerous pathogens
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What did Ignaz Semmelweis notice in Vienna Hospital?
He saw that women were dying in huge numbers after childbirth from a disease called puerperal fever
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What did Ignaz Semmelweis believe was the cause of the deaths?
He believed that doctors were spreading the disease on their unwashed hands
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How did Ignaz Semmelweis cut the death rate from 12% to 2%
He told doctors to wash their hands between wards with antiseptic solution
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Why were Semmelweis' methods dropped after he left?
He couldn't prove that the antiseptic solution killed bacteria because bacteria wasn't discovered until 20 years later
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What is a Stimulus?
A change in your environment which you may need to react to
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What are the 5 different sense organs?
1. Eyes 2. Ears 3. Nose 4. Tongue 5. Skin
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What are Receptors?
Groups of cells on Sense organs which are sensitive to a stimulus
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What do Receptors do?
They change stimulus energy into electrical impulses
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What are 7 examples of a stimulus?
1.Light 2.Sound 3. Touch 4. Pressure 5.Chemical 6.Change in position 7. Change in temperature
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What receptors do eyes have?
Light receptors - sensitive to light
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What receptors do ears have?
Sound and Balance receptors - sensitive to sound and changes in position
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What receptors does the nose have?
Smell receptors - sensitive to chemicals
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What receptors does the tongue have?
Taste receptors - sensitive to bitter, salt, sweet, sour and savoury (chemicals)
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What stimuli is skin sensitive to?
Touch, Pressure, Pain and Temperature change
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What is the Sensory neurone?
The nerve cells that carry signals as electrical impulses from the receptors in the sense organs to the central nervous system
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What is the Relay Neurone?
The nerve cells that carry signals from sensory neurones to motor neurones
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What is the motor neurone?
The nerve cells that carry signals from the central nervous system to the effector muscles
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What are Effectors?
Muscles and glands that respond to nervous impulses. Muscles contract, Glands secrete hormones
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What is the name given to the gap between neurones?
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What is the role of the central nervous system?
Where all the information is sent, and where reflexes and actions ae coordinated
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What does the central nervous system consist of?
The brain and Spinal cord
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What is the role of the Synapse?
Nerve signals from the neurones are transferred as chemicals which diffuse across the gap. These chemicals then set off a new electrical signal at the next neurone
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What is an automatic response?
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What is the passage of information in a Reflex called?
The Reflex Arc
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What do the neurones in reflex arcs go through?
The spinal cord
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Why are reflexes faster than normal responses?
Becuase you don't have to make a decision so it doesn't have to travel via the Brain
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What is Homeostasis?
Keeping everything in the body balanced
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What 4 things need to be kept constant in the body?
1. Ions 2. Water levels 3. Temperature (37 degrees C in humans) 4. Blood glucose level
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What 3 organs are vital in homeostasis and what do they excrete?
1. Lungs - lose water 2. Kidneys - excrete water, ions and urea 3. Skin - excretes water and ions
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What are Hormones?
Chemicals which are released into the blood to activate target cells
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Where are hormones produced?
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What effect do Hormones have?
Long - lasting
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What is stage 1 of the Menstrual cycle?
The Uterus lining breaks down for about 4 days
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What is stage 2 of the Menstrual cycle?
The lining of the Uterus build up again, into a thick spongy layer full of blood vessels ready to recieve a fertilised egg
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What is stage 3 of the Menstrual cycle?
An egg is developed and released from the Ovaries
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What is stage 4 of the menstrual cycle?
The wall is maintained for about 14 days. If no fertilised egg has landed on the Uterus wall, the lining breaks down
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What is the first hormone in the menstrual cycle, where does it come from, and what does it do?
FSH - comes from the Pituitary Gland - Causes the egg cell to mature and causes the Ovaries to release Oestrogen
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What is the second hormone in the menstrual cycle, where does it come from, and what does it do?
Oestrogen - comes from the Ovaries - Causes the Uterus lining to build up, Inhibits the production of FSH, and causes LH to be released
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What is the third hormone in the menstrual cycle, where does it come from, and what does it do?
LH - comes from the Pituitary gland - Causes the release of the egg cell
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How can taking Oestrogen everyday control fertility?
Keeping the level of Oestrogen permanently high inhibits the production of FSH and after a while, egg development and production stop and stay stopped
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How does Progesterone reduce fertility?
It stimulates the production of thick cervical mucus which prevents any sperm getting through
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What does the Combined pill contain?
Oestrogen and Progesterone
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What did the Comined pill used to only contain and why does it not anymore?
Used to only contain Oestrogen but it caused significant side effects
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What are 2 advantages of the Combined pill?
1. It's over 99% effective at preventing pregnancy 2. It reduces the risk of getting some cancers
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What are 3 disadvantages of the combined pill?
1. Very slight chance of pregnancy 2. Can cause side effects such as nausea and irregular menstruation 3. Doesn't protect from STD's
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What does the mini pill contain?
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How often and when does a woman have to take the Mini pill for it to be effective?
At the same time every day
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What is an advantage and a disadvantage of the mini pill?
A: It causes fewer side effects than the combined pill D: It is less reliable than the Combined pill
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What is the first step towards beginning the IVF process?
Fertility drugs are prescribed to make lots of eggs mature at the same time
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Explain the IVF process
Sperm is collected from male and eggs are collected from Female. They are mixed in a petri dish an eggs are (hopefully) fertilised. When embryos are formed, a couple are selected and are placed into the female's uterus where they implant
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What plant hormone controls Tropism?
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What is Phototropism?
Growth in response to light
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What is Gravitropism?
Growth in response to Gravity
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What is Hydrotropism?
Growth in response to Moisture
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What is common in IVF?
Twins or triplets
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Where is Auxin produced?
In the tip of the shoot
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What does Auxin stimulate?
The cell elongation process
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What are 4 uses of Auxin?
1, Weedkillers 2. Rooting powder 3. Fruit ripening 4. Control of dormancy
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What are drugs?
Chemicals that affect our body chemistry
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How do drugs affect the body?
They change chemical processes, causing them to become dependant or addicted to the drug
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What might drug addicts suffer and why?
They may suffer withdrawal symptoms if they don't have a drug they are addicted to
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What are the 3 types of drugs?
1. Medicinal 2. Recreational 3. Performance - enhancing
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What are Statins?
Prescribed drugs used to lower the risk of heart and circulatory disease
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What do Statins do?
Lower blood cholesterol and significantly lower the risk of heart disease in diabetic patients
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What is Cannabis known for? Give an example
People believe it is a very good painkiller. People with multiple sclerosis find it relieves their symptoms
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What are 3 negatives that Cannabis smoke has?
1. May lead to mental health problems 2. May lead the user onto addiction to hard drugs 3. Increase the risk of heart attacks and strokes
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What are 2 examples of Hard drugs?
1. Cocaine 2. Heroin
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What was Thalidomide intented as?
A sleeping pill
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What was Thalidomide later found to relieve?
Morning sickness in pregnant women
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Why was the use of Thalidomide as a morning sickness pill bad?
It stops the growth of the foetus' limbs and causes them to be born with limb abnormalities or none at all
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Why did we not know that Thalidomide affected pregnant women?
It was only tested as a sleeping pill and not as a pill for morning sickness
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What happened to the Thalidomide drug?
It was banned and more rigorous testing was introduced
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What is Thalidomide now used for?
Treatment for leprosy and other diseases
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What is the first step in Drug testing?
Drugs are tested on human cells in the lab
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What is the second step in Drug testing and why is it used?
They're tested on live animals to see if the drug works and to find out how toxic it is
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What is the law in Britain for animal drug testing?
New drugs must be tested on two different live mammals
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What is the third step in Drug testing?
They are tested on human volunteers in clinical trials
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Why are drugs tested on healthy volunteers in clinical trials and what is the procedure?
To make sure they don't have side effects. Low doses are given at first, then increased to see which works best.
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What is the second step during clinical trials for drugs?
The drug is tested on the people with the illness for optimum dose
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How are drugs tested on patients and why?
They are put into two groups. one given the drug and one a placebo. This is so the doctors can see the actual effect and check for the Placebo effect
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When is a drug licensed for use?
When it has passed all the trials and the two groups in the patient trials are compared and a difference is found
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What is a Placebo?
A dummy pill given to patients in clinical trials that are the control group
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What is the placebo effect?
When the patient expects the treatment to work and feels better even though the treatment isn't doing anything
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What are the two classes that illegal recreational drugs are divided into?
Soft and hard
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Why is Cannabis linked with hard drug use?
Cannabis is a stepping stone and creates a desire to try harder drugs. It is a gateway drug and brings peple into contact with dealers
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What are 2 legal recreational drugs?
1. Smoking 2. Alcohol
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What are 3 negatives of smoking?
1. Causes disease of the heart, blood vessels and lungs 2. Causes Cancer 3. Nicotine is addictive so it's difficult to stop smoking
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What are 4 negatives of alcohol?
1. It affects the nervous system and slows body reactions 2. Leads to impaired judgement, poor coordination and unconsciousness 3. Can damage the Liver and Brain 4. Is addictive
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What are 4 adaptations of desert animals?
1. Thin layers of body fat to help lose body heat 2. Large surface area to lose more heat 3. Sandy colour to camouflage 4. Produce small amounts of Urine and make very little sweat
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Why is camouflage good for an animal?
It helps to avoid predators or to sneak up on prey
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What are 4 adaptations of Artctic animals?
1. Have white fur to Camouflage 2. Have small surface area to reduce heat loss 3. Have a thick layer of blubber to insulate and store energy when food is scarce 4. Thick coats to keep heat in which is also greasy to shed water
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What are 3 adaptations of Desert Plants?
1.Efficient water storages (thick stems in Cactii) 2.Small leaves to not lose much water vapour 3. Small surface area to reduce water loss 4. Either shallow, extensive roots to absorb water quickly over a large area or deep roots to access water
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What are 3 protection adaptations with examples?
1. Armour (torns, spines, shells) 2. Poisons (bees and poison ivy) 3. Warning colours (wasps)
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What is an Extremophile?
An organism which lives in areas with extreme conditions
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What are 3 examples of areas extremophiles may live in?
Areas of 1. High salt 2. High temperature 3. High pressure
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What is the Advantage of being an Extremophile?
There are fewer organisms to compete with
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What is the Disadvantage of being an Extremophile?
The adaptations needed to survive are extreme
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What 4 things do animals compete over?
1. Space (Territory) 2. Food 3. Water 4. Mates
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What 4 things to Plants compete over?
1. Light 2. Space 3. Water 5. Minerals (nutrients)
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What are 4 living factors that affect environmental change?
A change in 1. The occurance of Infectious diseases 2. The number of Predators 3. The number of Prey or availability of food sources 4. The number of competitors
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What are 3 non living factors that affect environmental change?
A change in 1. The average temperature 2. The average Rainfall 3.The level of air or water pollution
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How might environmental change increase the population?
If the number of Prey increases, there's more available food for predators to survive and reproduce, so they increase
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How might environmental change decrease the population?
If there's more disease or less food etc
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What is population distribution change?
A change is distribution means a change in where an organism lives because of changes in temperature, rainfall, humidity, food, competition etc
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How are Lichen a type of living indicator?
They are sensitive to the concentration of Sulfur dioxide in the atmosphere (air pollution). So, the number and type of Lichen will indicate how clean the air is
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How are Mayfly Larvae a type of Indicator species?
They are good indicaors for water pollution as they are sensitive to the bacterial population. If you find them, water is Clean
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How is a satellite a non living indicator?
It measures the temperaure of the sea surface and the amount of snow and ice cover
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How are automatic weather stations non living indicators?
They tell us the atmospheric temperature in various locations
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How are rain gauges non living indicators?
They measure rainfall to find out how much average rainfall changes every year
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How are dissolved oxygen metres non living indicators?
They measure concentration of dissolved oxygen in water to see the change in water pollution level
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What is biomass?
The amount of living material in an organism
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What changes between the stages in pyramids of Biomss?
There's less energy and less biomass every time you move up a stage
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What do the bars in pyramids of biomass show?
Each bar shows the mass of a living material at that stage of the food chain
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What do the bars in pyramids of Biomass represent?
The big bar alongs the bottom always represents the producer, the next bar the primary consumer, then the secondary consumer and so on
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What is the source of energy for nearly all life on Earth?
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Where does the energy from a food chain begin?
Plants and Algae use the light enrgy to make food. This is stored in the cells which then goes through the food chain as animals eat each other
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What other energy is used and how is it lost from the food chain?
Respiration supplies energy for life processes. This is lost to the surroundings as heat
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How is energy lost from a food chain?
Material and energy are lost from food chains in waste
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Why are there biomass pyramids?
Because most of the biomass is lost and doesn't go to the next level up
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What 2 ways do living things return the materials they take from the world to the environment?
1. In waste products 2. When organisms die and are broken down by microorgansims
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What is mainly responsible for the decay of dead organisms and their waste?
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What 3 things does decomposition require?
1. Water 2. Warm temperature 3. Oxygen/ Aerobic conditions
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What is Respiration?
When living things release energy from Glucose. CO2 is released
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What is Detritus?
The remains of dead organisms and their waste
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What are Detritivores?
Organisms that feed on the remains of dead organisms and their waste
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What is photosynthesis?
When plants use sunlight, water and CO2 to make glucose
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What is Combustion?
The burning of a substance which releases CO2
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What is the atmospehre?
The layers of gases surrounding the planet
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In what way does CO2 leave the Earth's atmosphere in the Carbon cycle?
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What are 3 places that the CO2 used in photosyntheses in the carbon cycle next go to?
1. Makes wood 2. Makes food for animals 3. Goes back into the atmosphere in Plant respiration
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How does the making of wood the return CO2 into the atmosphere in the carbon cycle?
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How does the making of food return CO2 back into the atmosphere in th Carbon cycle?
Through animal respiration from the animals who eat the food. Andthrough the decay of their waste and dead bodies
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What other way do we get CO2 back into the atmosphere in the Carbon cycle?
The combustion of fossil fuels
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What are the 3 main ways that CO2 is put back into the atmosphere in the Carbon cycle?
1. Combustion 2. Plant + animal respiration 3. Decay
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Why do plants and animals have similar characteristics to their parents?
Because they are determined by the genes inherited from their parents
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How are genes pass on?
In Gametes (sex cells)
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What causes genetic variation?
The combining of genes from 2 parents. No two species are genetically identical other than identical twins
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What are 3 characteristics determined only by genes?
1. Eye colour 2. Blood group 3. Inherited disorders (e.g cystic fibrosis)
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What else causes variation other than genes?
The environment that organisms live and grow in also cause differences between the same species
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What is environmental variation?
Any difference that has been caused by the conditions something lives in
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What 4 characteristics are determined by a mixture of genetic and environmental factors?
1. Body weight 2. Height 3. Skin colour 4. Academic oe Athletic prowess
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Where are chromosomes found?
In the nucleus of the cells in your body
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How many chromosomes does the human cell nucleus contain?
23 pairs (46)
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Why are chromosomes always in pairs?
One from each parent in each pair, X and Y
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What do Genes control?
The development of different characteristics
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Where are Genes found?
On chromosomes. They are short lengths of the chromosome, which is a long length of DNA
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What do Genes carry?
The code for the production of a particular protein
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How is a fertilised egg with 46 chromosomes made?
From the fusion of two different gametes both containing 23 chromosomes
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Explain sexual reproduction
Involves the fusion of male and female gametes which contain 23 chromosomes to form a cell with 46, half from the father, half from the mother
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Why is there Variation in sexual reproduction?
Because there are 2 parents, the offspring contain a mixture of genetic material produces variation in the offspring
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Explain asexual reproduction
x-shaped chromosomes have two identical halves. Each chromosome splits down the middle and a membrane forms. The DNA then replicates itself so the cells are both identical
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Why are cells genetically identical in asexual reproduction
Because the cell divides in two and has exactly the same genetic information as the parent cell
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What is Tissue Culture cloning?
When gardeners take cuttings from good parent plants and use them to produce genetically identical copies. They do this by putting the cuttings in a petri dish containing Agar gel with nutrients for plant growth
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What are 4 advantages of tissue culture cloning?
1. Can be made quickly 2. Can be made cheaply 3. Can be made in very little space 4. Can be grown all year
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What happens in Embryo cloning?
Sperm and egg cells are artificially fertilised (IVF) and a resulting 'Zygote' forms. Then an Embryo forms (a ball of cells) and the different cells are put into surrogate females. Genetically identical animals are then born
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What happens in Adult cell cloning?
Unfertilised egg cell is taken and the nucleus is removed. Tissue cell with a complete set of chromosomes is taken and nucleus is removed. The tissue cell nucleus is fused with the empty egg cell after electric current is applied.
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What is the product of Adult cell cloning a clone of?
The tissue cell donor
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What are 2 disadvantages of cloning?
1. Reduced gene pool - if a population are closely related and a new disease appears, they could all be wiped out 2. Cloned animals may not be as healthy as normal ones
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What are 2 advantages of cloning?
1. Study of animal clones - greater understanding of embryo development and ageing 2. It can preserve endangered species
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How is genetic engineering used to create Insulin?
Insulin gene from a human cell is cut out of DNA by an enzyme. Plasmid from a bacterial cell is removed and split open by an enzyme. Insulin gene inserted into Plasmid by an enzyme. Plasmid with Insulin gene inserted in Bacteria. Bacteria multiplies.
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What are the pros of Genetic engineering?
It has the potential for solving problems i.e treating diseases, more efficient food production
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What are the cons of genetic engineering?
Changing a person's genes might accidentally create unplanned problems, which could then get passed on to future generations
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What are 4 reasons for GM crops?
1. Resistance to pests 2. Increasing nutrient levels 3. Resistance to herbicides 4. Improved shelf life
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What are 3 advantages of GM crops?
1. Can increase the yield of a crop, making more food 2. Developing countries often lack nutrients and GM crops can be engineered to contain the nutrient that's missing 3. They're already being grown elsewhere in the world without any problems
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What are 3 disadvantages of GM crops?
1. They will affect the number of weeds and flowers - reducing farmland biodiversity 2. They may not be safe. Allergies could develop 3. Transplanted genes may get into the natural environment
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What is the theory of Evolution?
More than 3 billion years ago, life on Earth began as simple organisms from which all the more complex organisms evolved
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Why might some species have similar genes?
Because they share a recent common ancestor
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Explain Natural Selection
Genetic mutations cause variation in species. If the environment changes, some organisms will be better suited to their environment than others. These organisms are more likely to survive and reproduce. The genes are passed on to the next generation
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What is a Mutation?
A change in an organism's DNA
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Why was Darwin's theory controversial at the time?
1. It went against common religious beliefs 2. He couldn't give a good explanation for why new characteristics appeared or how they were passed on 3. There wasn't enough evidence to convince many scientists
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What was Lamarck's theory?
That if a characteristic was used a lot by an organism then it would become more developed during it's lifetime. These aquired characteristics would then be passed on to the next generation
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Other cards in this set
What are the roles of Carbohydrates and Fats?
To release energy (Fats - to keep warm)
What is the role of Protein?
What is the role of Fibre?
What are the the roles of Vitamins and Minerals?