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132 Cards in this Set
- Front
- Back
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What 3 things provide energy for humans?
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Carbohydrates
Fats Proteins |
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What can a poor diet lead to? |
Weight problems |
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Where is cholesterol found and made?
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In the blood and in some foods
Liver |
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What are the 2 main types of pathogens? |
Virus |
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What do white blood cells do to deal with pathogens?
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Ingest
Antitoxins to neutralise the toxins from the pathogens Antibodies to destroy pathogens |
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What's smaller-Viruses or bacteria
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Viruses
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What are the 2 types of white blood cell?
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Phagocytes
Lymphocytes |
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What is the purpose of lymphocytes?
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They produce specific antibodies to fit the antigen, the reproduce quickly and make copies of the antibody, killing the pathogen
OR make it possible for the phagocytes to ingest the pathogens |
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What are antibodies?
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Proteins
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What is the purpose of a phagocyte?
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To ingest a pathogen
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What are the characteristics of bacteria?
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Very small
Reproduce quickly Produce toxins which is what creates symptoms when ill |
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What are the characteristics of viruses?
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Smaller than bacteria
Reproduce quickly once inside living cells (once inside they rip open the cell) Produce toxins |
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What is an epidemic?
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Local outbreak of disease
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What is a pandemic?
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Global outbreak of disease
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What is the problem with MRSA and why?
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Resistant to antibiotics due
Natural selection |
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When does antibiotic resistance occur?
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When the pathogens mutate
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How does antibiotic resistance increase?
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Over usage
Inappropriate antibiotics used |
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What do antibiotics treat?
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Bacteria
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State the sequence of the nervous system
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Receptor
Sensory Neurone Relay Neurone Spinal chord/brain Motor Neurone Effector |
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What do relay neurones do?
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Carry impulses to different parts of the CNS
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What is a stimuli?
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A change in the environment
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What is special about a reflex action?
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They by-pass the brain to make the reaction as quick as possible
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What is the term given to the gap with neurones?
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Synapse
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How are messages passed between neurones?
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Electrical impulse reaches synapse
Impulse is converted into chemicals which pass through the gap Receptors in the following neurone detect chemicals Electrical impulses are generated |
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Where are hormones produced?
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Glands
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What do hormones do?
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Coordinate processes
Regulate functions of organs and cells They travel to target organs in the blood stream |
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What does FSH stand for, where is it released and what is its purpose?
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Follicle stimulating hormone
Pituitary gland Causes the egg to mature |
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Where is oestrogen produced and what is its purpose?
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Ovaries
Inhibits production of FSH Causes production of LH |
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What does LH stand for, where is it produced and what is its purpose?
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Luteinising hormone
Pituitary gland Stimulates the release of an egg |
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How can you increase fertility?
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Give extra FSH and LH in a pill
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How can you reduce fertility?
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Give oestrogen and progesterone (birth control pill)
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What does IVF stand for?
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In Vitro Fertilisation
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What 3 things do plants respond to?
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Light
Moisture Gravity |
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What is the term given to a plants response?
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Tropism
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What are auxins?
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Hormones that control the way plants respond to light and gravity
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What is phototropism?
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A plants response to light
Auxins build up on the darker side of the plant, forcing the plant to grow towards the light |
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What is geotropism?
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A plants response to gravity
The auxins go to the side of the plant and forces the roots to grow downwards |
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What 3 substances are in cigarette smoke?
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Carbon Monoxide
Nicotine Carcinogens (causes cancer) |
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What can smoking tobacco cause?
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Bronchitis
Lung cancer Heart disease Emphysema (damage to alveoli caused by coughing) |
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What does carbon monoxide do?
Why is it bad for pregnant women to smoke? |
Reduce oxygen capacity within the blood
The fetus can be deprived of oxygen and therefore have a low birth mass |
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What 4 things do plants compete for?
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Light
Space Water Nutrients |
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What do animals compete for?
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Food
Mates Territory |
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What are extremophiles?
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Organisms that live in extreme environments
e.g high pressure, high temperatures, high salt levels |
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Where are chromosomes found?
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Nucleus
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What is a section of a chromosome?
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Gene
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What are chromosomes made of?
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DNA
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What are gametes?
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Sex cells
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What is the purpose of lichens?
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To detect air pollution because they are affected by sulphur dioxide levels
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What is the purpose of invertebrate animals?
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To detect water pollution and levels of dissolved oxygen
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What 3 things are required for decay to take place?
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Warmth
Moisture Oxygen (aerobic) |
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How many pairs of chromosomes are in the human body?
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23
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What are the processes of tissue culture?
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Cells are scraped from a plant
Cells are grown on agar with nutrients and hormones They are genetically identical to the parents |
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What causes immunity to a disease?
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If the white blood cells produce a specific antibody to kill the pathogen
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Which doctor reduced the number of deaths by insisting the doctors wash their hands before examining another patient?
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Semmelweiss
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What do antibiotics do?
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Kill infective bacterial pathogens
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Why is it hard to kill viral pathogens?
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Because they live and reproduce inside cells so its hard to develop a drug that kills viruses without damaging the body's own tissues
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What 3 things cause the spread of disease around the world?
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Mutations of pathogens
Global travel Antibiotic resistance |
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What happens when a pathogen mutates?
What does this mean? |
A new strain is made which may be resistant to antibiotics
This new resistant strain spreads rapidly because there is no effective treatment New antibiotics need to be developed all the time |
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Why are antibiotics not distributed for mild infections?
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To slow down the rate of antibiotic-resistant strains developing
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What happens when a bacterial infection is treated with antibiotics?
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Drugs kill individual pathogens of the non-resistant strain
Individual resistant strains survive and reproduce so the pathogen population of resistant strains rises |
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What is the most commonly used medium for the growth of microorganisms?
What is added to the agar to provide ideal growing conditions for microorganisms? |
Agar
Nutrients |
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How are uncontaminated cultures of microorganisms prepared?
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Sterilisation of petri dish and culture medium in an autoclave- High pressures and temperatures kill unwanted microorganisms
Sterilisation of inoculating loop by heating it till its red hot in a Bunsen flame (don't blow on it or wave it around otherwise it will pick up unwanted microorganisms) Transfer microorganisms using sterilised inoculating loop from container holding microorganism to the agar in petri dish Seal the petri dish so the microorganisms are not contaminated by the air Store upside down so condensation forms in the lid and not the agar Cultures can be incubated at a maximum of 25 degrees to prevent the growth of harmful pathogens |
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What percentage of body mass is made up of water?
Why is water vital? |
70%
For chemical reaction to take place properly and cleanse the body |
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What 4 things are necessary to control for humans to keep their internal environment constant?
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Temperature
Water content Ion content Blood sugar |
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Why is the balance of ions important?
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If they are not balanced, our cells shrivel or swell or even burst, causing damage to the body
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Why are blood sugar levels important?
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Because glucose provide your cells with a constant energy supply
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How does your body control its temperature?
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Shivering to increase the temperature
Sweating to lower the temperature |
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What 3 ways does water leave the body?
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Exhaling from the lungs
Sweating from he skin Urination via the kidneys (excess water) |
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How are ions carried?
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In water
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How are ions lost?
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Sweating
Urination |
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How can you gain glucose, water and ions?
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Eating and drinking
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What is glucose converted into?
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Energy
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What is energy used for?
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Movement
Keeping the body warm |
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What 2 things are produced using plant hormones?
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Weedkillers
Rooting powders-Stimulate roots to grow more quickly on plant cuttings |
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Why do plants respond to a stimuli?
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Due to an unequal distribution of hormones, varied levels of hormones produce different growth rates in different parts of the plant, causing them to bend
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What do plant growth substances control?
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Growth of shoots and roots
Flowering of plants Ripening of fruit |
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What 2 ways can drugs be obtained?
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Natural substances
Synthetically made |
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Why do drugs have an impact on your body?
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Because the interfere with chemical reactions taking place
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What must take place when a new drug is devised?
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Tested
Trialled |
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Why are live tissues and animals used in drug testing?
What'ss the problem with it? |
Allows scientists to predict how a drug may behave in humans
Some people view it as being unethical |
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At the start of clinical trials, why are low doses used to begin with?
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To see if the drug is safe
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Why do you test a drug by using different doses?
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To find its optimum dose (most effective)
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What do people suffer from once they stop taking the drug they are addicted to?
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Withdrawal symptoms which can be psychological (paranoia) and physical (sweating, vomiting)
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What do alcoholic drinks contain?
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Ethanol
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What effects does ethanol have on the body?
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Affects nervous system, causing reactions to slow down
Helps people relax Lack of self control Lead to unconsciousness, coma and death in excess amounts Lead to liver and brain damage |
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What can cannabis cause?
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Mental illness due to chemicals
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What are 2 examples enhancing drugs?
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Stimulants that boost bodily function such as heart rate
Anabolic steroids that stimulate muscle growth |
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What is an adaptation?
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A feature that makes an organism well suited to its environment
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What is good about having an adaptation?
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Increase organisms chance of survival
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How can an animal be adapted to live in an environment?
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Changes to surface area
Thickness of coat Amount of body fat Camouflage |
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How can plants be adapted to living in dry conditions?
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Smaller surface area of leaves
Water storage tissues Extensive root systems |
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How can the distribution of animals and be affected?
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Changes in the environment which may be living factors (new predator) or non-living factors (change in temperature)
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What example is there of a living factor that affected an animal?
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Red and grey squirrels
Native red squirrel can no longer compete with the very well adapted grey squirrel in deciduous woodlands, forcing the red squirrel to live in coniferous woodlands |
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What example is there of a non-living factor affecting an organism?
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The distribution of bees has changed due to disease, habitat loss and climate change
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Which animal is found in clean water with a high level of dissolved oxygen?
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Stonefly nymph
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Which animal will tolerate low levels of oxygen and is found in polluted water?
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Rat-tailed maggot
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What is a source of energy for all communities of living organisms?
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Radiation from the Sun
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What happens when an animal eats a plant?
How can this be represented? |
They gain the stored energy within the plant that was obtained through photosynthesis
In a food chain |
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What is biomass?
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The mass of a living material
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What is the relationship between biomass and the food chain stage?
How can this be shown? |
The biomass at each stage of the food chain is less than it was in the previous stage
In a pyramid of biomass |
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Why is biomass and energy lost at every stage of a food chain?
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Materials and energy are lost in an organisms waste material
Energy released through respiration (used for heat and movement) is eventually transferred to the surroundings |
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How can efficient food production be achieved?
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Reducing the number of stages in a food chain
Limiting animals movement Controlling animals temperature |
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What are the stages of a food chain?
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Producer (normally plants)
Primary consumer Secondary consumer Tertiary consumer |
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What happens to the removed materials in an animal which were previously from the environment?
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Eventually returned when they excrete waste or die and decay
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Why do microorganisms break down/digest waste and dead bodies?
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The decay process releases substances needed by plants to grow
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When do microorganisms digest/break down materials faster?
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When the environment is:
Warm Moist Aerobic (rich in oxygen) |
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What 2 processes are balanced in a stable community?
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Removal of materials from environment
Return of materials to environment |
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What is the first stage of the carbon cycle?
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Carbon dioxide is removed from environment through photosynthesis through green plants
Some carbon dioxide is returned to atmosphere when green plants respire |
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What is the second stage of the carbon cycle?
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Plants use carbon from carbon dioxide to make carbohydrates, fats and proteins.
When animals eat plants, some of the carbon becomes part of the fats and proteins that make up their bodies |
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What is the third stage of the carbon cycle?
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Animals respire, releasing carbon dioxide into the atmosphere
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What is the fourth stage of the carbon cycle?
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When organisms die, other animals and microorganisms feed on their bodies or waste, causing them to break down
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What is the fifth stage of the carbon cycle
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Carbon dioxide is released into the atmosphere when detritus feeds and microorganisms respire
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Why does variation occur?
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Combination of genes
Environmental factors |
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What happens in sexual reproduction?
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Male and female gametes fuse together-Fertilisation
Process produces lots of variation |
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What happens in asexual reproduction?
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Doesn't produce any genetic variation because only one parent is needed so there is no mixing of genes
Offspring are genetically identical to the parent-clones Variation may only occur due to environmental factors |
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What is the process of tissue culture to produce clones?
What are the genetic characteristics of the offspring? |
Small groups of cells are scraped from plant
Cells are grown on agar containing nutrients and hormones Genetically identical to parent plant |
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What is the process of embryo transplants to produce clones?
What are the genetic characteristic of the offspring? |
Cells from a developing animal embryo are split before they become specialised
Resulting identical embryos are transplanted into host mothers Offspring are genetically identical to each other but not the parent |
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What is the process of adult cell cloning?
What are the genetic characteristics of the offspring? |
Nucleus removed from an unfertilised egg cell
Nucleus from adult body cell is then inserted into the empty egg cell Electric shock causes egg cell to begin dividing to form an embryo Embryo inserted into a host mother Offspring is genetically identical to the donor animal (nucleus donor) |
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What is genetic modification?
What are the processes? |
Involves transferring genetic material from one organism to another
Individual genes are cut out of the chromosomes of an organism using enzymes Genes are then transferred to the cells of another organism |
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Why is genetic modification performed at an early stage in their development?
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So that they develop with desired characteristic
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In crop plants, what are some examples of a desirable characteristic?
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Improved yield
Improved resistance to pests Longer shelf life |
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What are crops called that have had their genes modified?
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Genetically modified crops (GM crops)
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Why are GM crops a concern?
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They might have an effect on wild populations
The human health effects of eating GM crop are unknown |
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Why do people compare organisms?
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Classifies organisms into specific species
Helps to understand evolutionary and ecological relationships between organisms |
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What did Charles Darwin come up with?
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The theory of evolution by natural selection
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Why did it take so long for Charles Darwin's theory to be accepted?
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Challenged idea that God created all life
Insufficient evidence at the time to convince scientists Mechanism of inheritance and variation was discovered until 50 years later |
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What was the theory of evolution?
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If an organism has a characteristic that makes life easier due to genetic variation, they are more likely to survive and therefore reproduce, passing on this desired characteristic
The change in a population over many generations and may result in a new species arising which is better adapted |
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What was Jean-Baptiste Lamarck's theory?
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A theory of evolution that included a change that occurs during the lifetime of an organism and will then be passed on to its offspring
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What may bring about a more rapid change in species?
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Mutations
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What happens to the metabolic rate during exercise and after?
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It increases during exercise and stays high for a while after exercise
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Why is cholesterol needed?
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For a healthy cell membrane
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What is involved in a vaccination?
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Injecting a small amount of an inactive or dead pathogen into the body
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