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147 Cards in this Set

  • Front
  • Back
What 3 things provide energy for humans?
Carbohydrates
Fats
Proteins
If someone has an unbalanced diet what are they?
Malnourished
What can a poor diet lead to?
Weight problems
Deficiency diseases (Type 2 diabetes)
When do you loose weight?
When the amount of energy in food is less than amount of energy used in the body
What is metabolic rate?
The rate of chemical reactions within the body
What is the metabolic rate affected by?
Amount of exercise
Inherited factors
Proportion of fat to muscle
Where is cholesterol found and made?
In the blood and in some foods
Liver
The amount of cholesterol depends on what?
Diet
Inherited factors
What are the 2 main types of pathogens?
Virus
Bacteria
What do white blood cells do to deal with pathogens?
Ingest
Antitoxins to neutralise the toxins from the pathogens
Antibodies to destroy pathogens
What does LDL stand for and what do they do?
Low density lipoproteins
Carry cholesterol from liver to cells
Name 3 bacteria infections
Tetanus
Whooping cough
Food poisoning
Cholera
TB
Name 3 viruses
Mumps
Measles
Rubella
Colds
Flu
Polio
What's smaller-Viruses or bacteria
Viruses
What are the 2 types of white blood cell?
Phagocytes
Lymphocytes
What is the purpose of lymphocytes?
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
What are antibodies?
Proteins
What are the foreign chemicals within a pathogen?
Antigen
Toxins
What is the purpose of a phagocyte?
To ingest a pathogen
What are the characteristics of bacteria?
Very small
Reproduce quickly
Produce toxins which is what creates symptoms when ill
What are the characteristics of viruses?
Smaller than bacteria
Reproduce quickly once inside living cells (once inside they rip open the cell)
Produce toxins
What is an epidemic?
Local outbreak of disease
What is a pandemic?
Global outbreak of disease
What is the problem with MRSA and why?
Resistant to antibiotics due
Natural selection
When does antibiotic resistance occur?
When the pathogens mutate
How does antibiotic resistance increase?
Over usage
Inappropriate antibiotics used
What do antibiotics treat?
Bacteria
State the sequence of the nervous system
Receptor
Sensory Neurone
Relay Neurone
Spinal chord/brain
Motor Neurone
Effector
What do relay neurones do?
Carry impulses to different parts of the CNS
What is a stimuli?
A change in the environment
What is special about a reflex action?
They by-pass the brain to make the reaction as quick as possible
What is the term given to the gap with neurones?
Synapse
How are messages passed between neurones?
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
Where are hormones produced?
Glands
What do hormones do?
Coordinate processes
Regulate functions of organs and cells
They travel to target organs in the blood stream
What does FSH stand for, where is it released and what is its purpose?
Follicle stimulating hormone
Pituitary gland
Causes the egg to mature
Where is oestrogen produced and what is its purpose?
Ovaries
Inhibits production of FSH
Causes production of LH
What does LH stand for, where is it produced and what is its purpose?
Luteinising hormone
Pituitary gland
Stimulates the release of an egg
How can you increase fertility?
Give extra FSH and LH in a pill
How can you reduce fertility?
Give oestrogen and progesterone (birth control pill)
What does IVF stand for?
In Vitro Fertilisation
What 3 things do plants respond to?
Light
Moisture
Gravity
What is the term given to a plants response?
Tropism
What are auxins?
Hormones that control the way plants respond to light and gravity
What is phototropism?
A plants response to light
Auxins build up on the darker side of the plant, forcing the plant to grow towards the light
What is geotropism?
A plants response to gravity
The auxins go to the side of the plant and forces the roots to grow downwards
What is the definition of a drug?
A chemical substance that alters the way your body works
What are statins?
A drug that lowers cholesterol in the blood which therefore reduces the risk of heart disease
Can be found naturally in some foods
What are new drugs tested for?
Toxic content
Efficiency of drug
The dose needed
What is a double blind trial?
What's good about it?
When a placebo may be used (a fake drug) which neither doctor nor patient knows the difference.
Reduces biased results
Why do they use a lower dosage at the start of a clinical trial?
To see if the drug is safe, if so then more doses are used to find the optimum (most effective) dose for the drug
What is thalidomide?
What was it used for without being tested for the purpose?
What were the outcomes?
What has it been discovered to treat?
A sleeping pill
Morning sickness
Thalidomide was banned due to babies being born with severe limb abnormalities
Leprosy
What 3 substances are in cigarette smoke?
Carbon Monoxide
Nicotine
Carcinogens (causes cancer)
What can smoking tobacco cause?
Bronchitis
Lung cancer
Heart disease
Emphysema (damage to alveoli caused by coughing)
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
What 4 things do plants compete for?
Light
Space
Water
Nutrients
What do animals compete for?
Food
Mates
Territory
What are extremophiles?
Organisms that live in extreme environments
e.g high pressure, high temperatures, high salt levels
Where are chromosomes found?
Nucleus
What is a section of a chromosome?
Gene
What are chromosomes made of?
DNA
What are gametes?
Sex cells
What is the purpose of lichens?
To detect air pollution because they are affected by sulphur dioxide levels
What is the purpose of invertebrate animals?
To detect water pollution and levels of dissolved oxygen
What 3 things are required for decay to take place?
Warmth
Moisture
Oxygen (aerobic)
How many pairs of chromosomes are in the human body?
23
What are the processes of tissue culture?
Cells are scraped from a plant
Cells are grown on agar with nutrients and hormones
They are genetically identical to the parents
What causes immunity to a disease?
If the white blood cells produce a specific antibody to kill the pathogen
Which doctor reduced the number of deaths by insisting the doctors wash their hands before examining another patient?
Semmelweiss
What do antibiotics do?
Kill infective bacterial pathogens
Why is it hard to kill viral pathogens?
Because they live and reproduce inside cells so its hard to develop a drug that kills viruses without damaging the body's own tissues
What 3 things cause the spread of disease around the world?
Mutations of pathogens
Global travel
Antibiotic resistance
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
Why are antibiotics not distributed for mild infections?
To slow down the rate of antibiotic-resistant strains developing
What happens when a bacterial infection is treated with antibiotics?
Drugs kill individual pathogens of the non-resistant strain
Individual resistant strains survive and reproduce so the pathogen population of resistant strains rises
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
How are uncontaminated cultures of microorganisms prepared?
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
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
What 4 things are necessary to control for humans to keep their internal environment constant?
Temperature
Water content
Ion content
Blood sugar
Why is the balance of ions important?
If they are not balanced, our cells shrivel or swell or even burst, causing damage to the body
Why are blood sugar levels important?
Because glucose provide your cells with a constant energy supply
How does your body control its temperature?
Shivering to increase the temperature
Sweating to lower the temperature
What 3 ways does water leave the body?
Exhaling from the lungs
Sweating from he skin
Urination via the kidneys (excess water)
How are ions carried?
In water
How are ions lost?
Sweating
Urination
How can you gain glucose, water and ions?
Eating and drinking
What is glucose converted into?
Energy
What is energy used for?
Movement
Keeping the body warm
What 2 things are produced using plant hormones?
Weedkillers
Rooting powders-Stimulate roots to grow more quickly on plant cuttings
Why do plants respond to a stimuli?
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
What do plant growth substances control?
Growth of shoots and roots
Flowering of plants
Ripening of fruit
What 2 ways can drugs be obtained?
Natural substances
Synthetically made
Why do drugs have an impact on your body?
Because the interfere with chemical reactions taking place
What must take place when a new drug is devised?
Tested
Trialled
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
At the start of clinical trials, why are low doses used to begin with?
To see if the drug is safe
Why do you test a drug by using different doses?
To find its optimum dose (most effective)
What do people suffer from once they stop taking the drug they are addicted to?
Withdrawal symptoms which can be psychological (paranoia) and physical (sweating, vomiting)
What do alcoholic drinks contain?
Ethanol
What effects does ethanol have on the body?
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
What can cannabis cause?
Mental illness due to chemicals
What are 2 examples enhancing drugs?
Stimulants that boost bodily function such as heart rate
Anabolic steroids that stimulate muscle growth
What is an adaptation?
A feature that makes an organism well suited to its environment
What is good about having an adaptation?
Increase organisms chance of survival
How can an animal be adapted to live in an environment?
Changes to surface area
Thickness of coat
Amount of body fat
Camouflage
How can plants be adapted to living in dry conditions?
Smaller surface area of leaves
Water storage tissues
Extensive root systems
How can the distribution of animals and be affected?
Changes in the environment which may be living factors (new predator) or non-living factors (change in temperature)
What example is there of a living factor that affected an animal?
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
What example is there of a non-living factor affecting an organism?
The distribution of bees has changed due to disease, habitat loss and climate change
Which animal is found in clean water with a high level of dissolved oxygen?
Stonefly nymph
Which animal will tolerate low levels of oxygen and is found in polluted water?
Rat-tailed maggot
What is a source of energy for all communities of living organisms?
Radiation from the Sun
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
What is biomass?
The mass of a living material
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
Why is biomass and energy lost at every stage of a food chain?
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
How can efficient food production be achieved?
Reducing the number of stages in a food chain
Limiting animals movement
Controlling animals temperature
What are the stages of a food chain?
Producer (normally plants)
Primary consumer
Secondary consumer
Tertiary consumer
What happens to the removed materials in an animal which were previously from the environment?
Eventually returned when they excrete waste or die and decay
Why do microorganisms break down/digest waste and dead bodies?
The decay process releases substances needed by plants to grow
When do microorganisms digest/break down materials faster?
When the environment is:
Warm
Moist
Aerobic (rich in oxygen)
What 2 processes are balanced in a stable community?
Removal of materials from environment
Return of materials to environment
What is the first stage of the carbon cycle?
Carbon dioxide is removed from environment through photosynthesis through green plants
Some carbon dioxide is returned to atmosphere when green plants respire
What is the second stage of the carbon cycle?
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
What is the third stage of the carbon cycle?
Animals respire, releasing carbon dioxide into the atmosphere
What is the fourth stage of the carbon cycle?
When organisms die, other animals and microorganisms feed on their bodies or waste, causing them to break down
What is the fifth stage of the carbon cycle
Carbon dioxide is released into the atmosphere when detritus feeds and microorganisms respire
Why does variation occur?
Combination of genes
Environmental factors
What happens in sexual reproduction?
Male and female gametes fuse together-Fertilisation
Process produces lots of variation
What happens in asexual reproduction?
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
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
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
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)
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
Why is genetic modification performed at an early stage in their development?
So that they develop with desired characteristic
In crop plants, what are some examples of a desirable characteristic?
Improved yield
Improved resistance to pests
Longer shelf life
What are crops called that have had their genes modified?
Genetically modified crops (GM crops)
Why are GM crops a concern?
They might have an effect on wild populations
The human health effects of eating GM crop are unknown
Why do people compare organisms?
Classifies organisms into specific species
Helps to understand evolutionary and ecological relationships between organisms
What did Charles Darwin come up with?
The theory of evolution by natural selection
Why did it take so long for Charles Darwin's theory to be accepted?
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
What was the theory of evolution?
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
What was Jean-Baptiste Lamarck's theory?
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
What may bring about a more rapid change in species?
Mutations
What happens to the metabolic rate during exercise and after?
It increases during exercise and stays high for a while after exercise
Why is cholesterol needed?
For a healthy cell membrane
What is involved in a vaccination?
Injecting a small amount of an inactive or dead pathogen into the body