biology core science revision flash cards produced by mr p scutt

Biology Core ScienceRevision Flash Cards

Produced by Mr P Scutt

What is meant by a balanced diet?


What is meant by a balanced diet?


A diet that keeps you healthy and provide you with enough energy.

Must have:- Carbohydrates for energy- Fats for warmth and energy- Protein for growth and repair

- Fibre to keep things moving in the digestive system - Vitamins and minerals – to keep you healthy

Why do people need different diets?


What are the possible effects of having an unbalanced diet?


Why do people need different diets?


Everyone is different and so:

- Need more protein for muscle growth- Carbohydrates for energy

People also have different ‘metabolic rates’ which is the rate at which chemical reactions take place inside the body. Men’s tend be higher rates and it is controlled genetically.

What are the possible effects of having an unbalanced diet?


Obesity – excess carbohydrates – leads also to artritus, diabetes, high blood pressure and heart disease.

Cholesterol – excess saturated fat – leads to fatty deposits in arteries and so leads to heart disease.

Salt – leads to high blood pressure and heart problems.

Too little food – slow growth, fatigue, infection, irregular periods, scurvy (vitamin C deficiency)

What inherited factors affect your health?


Compare the two main types of pathogens.


What inherited factors affect your health?


Metabolic rate – speed of chemical process in cells

Blood cholesterol level - fatty deposits in arteries leading to heart disease

Compare the two main types of pathogens.


Living? Size Effects

Bacteria Living Very small Produce toxins Damage cells

Virus Non-living Tiny cells, smaller than bacteria

Use living cells to produce copies of themselves. Cell eventually burstsCauses cell damage

Describe the ways that the body defends against pathogens.


How do vaccinations work?


Describe the ways that the body defends against pathogens.


Skin – barrier to pathogensMucus and hairs – trap pathogens in nose and breathing system

Cut are sealed quickly by platelets in the blood

Immune system can kick in if enters:1. Can consume them – engulf and eat them.

2. Can produce antibodies to lock on to invading cells and kill them. These need time to be produced. 3. Produce antitoxins – counteract toxins produced by bacteria

How do vaccinations work?


Small amounts of dead or inactive microorganisms are injected into the bodyThese carry antigens which cause your body to produce antibodies

This means that the body has the necessary antibodies if the person become infected with the live and dangerous microorganism.

Sometimes a booster is required to ensure that the body have enough antibodies.

Used for MMR (Measles, mumps and rubella)

What are the issues surrounding vaccination?


What are the issues surrounding antibiotics?


What are the issues surrounding vaccination?


Pros Cons

Control infectious diseases Don’t always work

Wiped out smallpox Side-effects can occur

They can be used to try and prevent an epidemic

What are the issues surrounding antibiotics?


Pros Cons

Kill bacteria Only kill bacteria

Important that whole course is completed to kill all bacteria

Over use can lead to antibiotic resistance as bacteria mutate,

e.g. MRSA.

Specific antibiotics kill specific bacteria

What work did Semmelweis do?


What are the main sense organs and what receptors are found in them?


What work did Semmelweis do?


Following the death of a number of women after child birth he realised:

- Unwashed hands were the cause of spreading of diseases- Antiseptics were needed to prevent/reduce spread

- Work led to basic hygiene procedures being adopted

What are the main sense organs and what receptors are found in them?


Organ Receptors

Eyes Light

Ears Sound & balance

Nose Smell – chemicals

Tongue Taste – chemicals

Skin Touch, pressure, pain and temperature

What is a synapse and how does it work?


What are the main steps within a reflex arc?


What is a synapse and how does it work?


A synapse is a junction between two nerve cells (neurones)They work by producing a chemical (neurotransmitter)

Between a gap. If enough neurotransmitter is produced it will stimulate the next neurone

What are the main steps within a reflex arc?


Stage How it prevents harm being caused.

Stimulus What causes the reflex

Receptor The cells that detect the change

Sensory neurone

Carries an electrical impulse to the CNS

CNS Central nervous system, made up of the brain and spinal cord. A relay neurone is found here to bridge the gap between the sensory and motor neurone

Motor neurone Carries an electrical impulse to the effector

Effector A muscle or gland that responds by moving or releasing a hormone

Response What happens as a result – e.g. movement

What are hormones used for and how are they different to nerves?


What are the main stages in the menstrual cycle?


What are hormones used for and how are they different to nerves?


Transmission of message by

Speed of transmission

Uses Area affects Example

Hormones Chemicals Slow Blood Large area – general

Adrenaline, FSH, LH, Oestrogen

Nerves Electrical impulses

Fast Nerve cells (neurones)

Small and precise area

Sensory, motor, relay

What are the main stages in the menstrual cycle?


Stage Day Event Hormones

1 1-4 Bleeding – the uterus breakdown FSH from pituitary gland cause egg in ovary to develop and stimulates oestrogen production

2 4-14 Lining of the uterus builds up with fresh food and blood supplies.

Oestrogen from ovary is produced to stimulate lining of uterus to develop. FSH is stopped.

3 14 Egg is released - ovulation LH from pituitary gland causes ovulation

4 28 Lining is maintained if fertilised egg is received. Process starts again if no fertilised egg

Progesterone from ovary, maintains lining

How can we control fertility?


What are auxins and where are they found?


How can we control fertility?


Reduce fertility (the pill) Increase

Oestrogen – prevents egg release as stops FSH which would normally cause the egg to develop in the ovary.

Injections of FSH to help more eggs to develop.

Progesterone – produces a cervical mucus which prevents the sperm reaching the egg.

Injections of LH to help ovulation.

ISSUES: 99% effective, can lead to blood clots, can reduce risk of cancer, side effects of headaches and sickness, doesn’t prevent STDs

IVF – where eggs are taken from the ovary and fertilised with sperm outside of the body. They are then rejected once they are confirmed to be successfully dividing. Prior to procedure, FSH and LH are used to increase egg production.

What are auxins and where are they found?


They are plant hormones that control growth

Found in the tops of shoots and roots

They respond to light (phototropism), gravity (geotropism), water (hydrotropism)

They move backwards to cause cell elongation just behind the tip.

What affect do auxins have in plants?


What is meant by homeostasis and what does it control?


What affect do auxins have in plants?


Area of plant affected

On Shoots On shoots On Roots On Roots

Responding too Light Gravity Gravity Water

Name of tropism

Phototropism Geotropism Geotropism Hydrotropism

Where auxins accumulate

On the shaded side

Lower side Lower side Side with more moisture

Which cells grow

Shaded sided so that the shoot bends towards the light

Lower side grows faster so shoot grows upwards

Inhibits growth so that the root grows downwards

Inhibits growth so root bends towards the water

What is meant by homeostasis and what does it control?


The maintenance of a constant internal environment – i.e. it keeps things at normal levels

Temperature – 37C in humansBlood glucose

Carbon dioxide Ions in the blood

Water

What do drugs do in your body?


How can drugs be used to improve performance?


What do drugs do in your body?


They change the bodies chemistry by interfering with chemical reactions

Good:- Relieve symptoms – headaches

- Help fight bacterial infections – antibiotics

Can cause:- Addition

- Withdrawal symptoms

How can drugs be used to improve performance?


Steroids:- Increase muscle size

- Increase heart rate – pump blood quicker around the body and so deliver more glucose and oxygen to cells.

Negatives:- Can cause high blood pressure- Unfair advantage in competition

- Serious health problems

What are statins used for?


How are new drugs tested?


What are statins used for?


Lowering the risk of heart and circulatory disease

Lower blood cholesterol levels

How are new drugs tested?


1. Tested on human cells and tissues in a lab.2. Tested on live animals – see if works, any toxicity, best dosage (in UK each drug must be tested on 2 animals)

3. Human volunteers in a clinical trial:i. Group 1 – healthy people to see if any side effects – very lose dose given.

ii. People with the illness – find optimum doseiii. Given to two groups – one has a placebo and the other the actual drug.

These tests on humans are ‘blind-tests’ so they don’t know if they have the placebo or the actual drug and therefore cant influence the results.

What is thalidomide and the story linked to it?


What effects does smoking and alcohol have?


What is thalidomide and the story linked to it?


A drug given in the 1950sIntended as a sleeping pill

Seen though to help with morning sickness tooThe drug was therefore given to pregnant women

Lead to babies being born with abnormal limb development, no arms, no legs

Drug was then banned, but has since been used for treatment of leprosy.

What effects does smoking and alcohol have?


Smoking Alcohol

Heart diseaseLung disease

Affect nervous system – slows reactions

Cancer Can impair judgements and lead to unconsciousness

Addictive due to nicotine Liver disease Brain damage

Addictive

How are animals adapted?


How are plants adapted?


How are animals adapted?


Desert Animals Artic Animals

Surface area to volume ratio

Large – so lose more heat Small – so retain heat

Water loss Limited by – producing concentrated urine, little sweat produced, find shelter

Not as much of a problem.

Insulation Very thin layers of fat – can have a hump instead

Lots of blubber to keep warm and also as an energy store.Thick fury coats.

Camouflage Sandy coloured so avoid predators

White fur to avoid predators

How are plants adapted?


Small surface area:volume ratio reduces water loss (spines are best).

Store water in stem (catcus)

Shallow roots to absorb water quickly

Deep roots – greater area to gain water

Thorns/Poisons/Warning colours – protection

What do organisms compete for?


What factors cause environmental change?


What do organisms compete for?


Plants Animals

Light Space

Space Food

Water Water

Nutrients (minerals) Mates

What factors cause environmental change?


Living Factors Non-living factors

Infectious diseases Temperature

Predators Rainfall

Prey (availability of food) Air pollution

Number of competitors Water pollution

How can environmental changes be measured using living indicators?


How can environmental changes be measured using non-living indicators?


How can environmental changes be measured using living indicators?


Air pollution Water pollution

Lichens – sensitive to sulfur dioxide (from car exhausts). Lots of lichens, clean air.

Mayfly lavae – Raw sewage in water means that more bacteria grow and so use up more oxygen. More larvae, cleaner the water.

Maggots/Sludgeworms – lots, means it is very polluted.

How can environmental changes be measured using non-living indicators?


Satellites – measure temperature, amount of snow, sea surfaces

Weather stations – temperature

Rainfall

Oxygen meters – check oxygen levels in water

What do pyramids of biomass show?


What energy transfers occur along a food chain?


What do pyramids of biomass show?


Show the mass of living material in each stage of a food chain.

As you go down a food chain, the biomass reduces because:

- Energy is used up at each level – respiration, growth, maintaining body temperature, producing waste, - Not all of the animal is eaten by the next animal in the food chain

Start with a producer – plant which uses energy from the Sun. Then primary consumer

Then secondary consumer.

What energy transfers occur along a food chain?


Energy is used up at each level – - Respiration – releasing energy from food

- growth, - maintaining body temperature,

- producing waste,

What happens in Decay?


What are the main stages in the carbon cycle?


What happens in Decay?


Plants and animals are made up of Carbon, Oxygen, NitrogenWhen they die, they are broken up by microorganisms

The miorco-organisms respire and so release carbon dioxide to the atmosphere

They need warm coniditions with oxygen – e.g. compost bin

What are the main stages in the carbon cycle?


The cycle of carbon around the world. The key movements are:

Respiration – releases carbon dioxideBurning fossil fuels/wood – releases carbon dioxide

Decay of dead matter – releases carbon dioxide

Photosynthesis – absorbs carbon dioxide Eating plants – moves carbon to animals and is used to form carbohydrates, fats and proteins

How is variation caused?


What is a chromosome made up of and do?


How is variation caused?


Genetic – what genes you inherit from mum and dad, e.g. eye colour

Environment – what happens to you in your life, e.g. sun tan, diet,

What is a chromosome made up of and do?


Inside the nucleus there are chromosomesChromosomes are made of DNA

A small section of DNA is called a gene and codes for a characteristic

DNA – is coiled and made up of 2 strands

What is the difference between sexual and asexual reproduction?


How are clones formed using tissue culture and cuttings?


What is the difference between sexual and asexual reproduction?


Sexual Asexual

Example Cells involved

2 x Gametes – your sex cells – sperm and egg.

Normal cells – skin cells,

Offspring Genetically different from parents as genes mix.

Identical – Clones.

Number of chromosomes in cells

23 in each gamete producing offspring with 46 when combined.

46 in parent, 46 in offspring

Used for Reproduction Growth and repair

How are clones formed using tissue culture and cuttings?


Cuttings from plants takenGrown to produce identical clones

QuickCheap

Few plant cells are takenGrown in growth medium with hormones

New plants producedQuick

Little space neededGrown all year round

How are clones formed using embryo transplants?


How are clones formed using adult cells?


How are clones formed using embryo transplants?


Sperm taken from ideal dad, e.g. bullEgg taken from ideal mum, e.g. cow

Egg fertilised with sperm in labEmbryo produced

Embryo implanted in to many different mums (cows)Produce genetically identical offspring

How are clones formed using adult cells?


Adult cell taken, e.g. skin cellEgg cell taken and nucleus removed.

Chromosomes of adult cell inserted into empty eggGiven electric shock

Implanted back into femaleClone produced – e.g. dolly the sheep.

What are the main steps in genetic engineered insulin?


What is evolution and how can it be explained using natural selection?


What are the main steps in genetic engineered insulin?


Useful gene identifiedGene cut out of chromosome

Using enzyme

Enzyme use to cut another piece of DNA from a different organism (usually a bacteria)Ideal gene inserted

Bacteria divide and produce more copies of new DNA

Can be used for transferring gene for different characteristics, e.g. fruitiness in tomatoes, resistance to insects, replace faulty genes, produce insulin

What is evolution and how can it be explained using natural selection?


Evolution is how from simple cells, more complex organisms have come about over time.

Darwin – suggested every species has variation (differences) and that because of natural selection, whereby animals with the characteristics most suitable to environment survive and reproduce. Therefore, their genes are passed on to the next generation.

Difference in genetics can be due to mutations – where the DNA is slightly changes. Sometimes this has no effect, at others times new characteristic can come about.

How does Darwin’s work differ from Lamarck?


How does Darwin’s work differ from Lamarck?


Darwin – evolution due to natural selection and survival of the fittest.

Lamarck – characteristics that were used a lot by animals became more developed in its life time, e.g. rabbit used its legs to run and so its legs got longer.

biology core science revision flash cards produced by mr p scutt

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