Science A (Core): Biology Flashcards

1
Q

What are the 5 senses?

A

Smell

Sight

Taste

Touch

Hearing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the different sense organs, and what do they sense?

A

Eye – light

Skin – touch, temperature, pressure, pain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the job of the nervous system?

A

To sense and respond to the outside environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the nervous system made up of?

A

Nerves (sensory, motor and relay neurons), spine & brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is a receptor? Give some examples

A

A receptor receives information from the outside environment

Eye – light

Nose – smell

Skin – pressure & temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the job of a sensory neurone?

A

To take information from the receptor to the CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the job of a motor neurone?

A

To take information from the CNS to the effector (muscle / gland)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the job of a relay neurone?

A

A relay neurone passes information within the CNS – these are used in reflex reactions to pass information straight from a sensory neurone to a motor neurone, bypassing the brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is a synapse and how does it work?

A

A synapse is the gap between 2 nerves – chemicals called neurotransmitters pass across the gap

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is an effector?

Give an example of an effector in a reflex reaction?

A

An effector is the muscle or gland that is targeted in a nervous response (e.g. you blink because you have dust in your eye (the effector is the muscle in the eye lid))

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What happens in a reflex action?

A

Receptor → sensory neurone → relay neurone → CNS → motor neurone → effector

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What conditions within the body need to be controlled?

A

Temperature (37°C)

Water level

Ion level

Glucose level

Carbon dioxide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How does water leave the body?

A

Sweat

Breath

Urine (via kidneys)

Faeces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How are ions lost from the body?

A

Sweat

Urine (via kidneys)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Why is it important to control temperature & how is this controlled?

A

Temperature must be controlled as enzymes work best at 37°C – temperature is controlled by skin and blood vessels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is a hormone, and where are they secreted from?

A

Hormones are chemical substances that control processes within the body – they are secreted by glands (e.g. the adrenal and pituitary gland)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How do hormones travel around the body?

A

In the blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the main differences between a hormonal and nervous reaction?

A

Hormonal control: -

Slow

Travel within blood

Go to whole body

Nervous control: -

Fast

Travel via nerves

Go to a specific organ

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Why is it important that blood sugar levels are controlled?

A

To maintain a constant energy supply

Too high or too low blood sugar levels can result in a coma / death

Blood sugar is controlled by the hormone insulin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the function of the hormone oestrogen and where is it secreted from?

A

Oestrogen, secreted from the ovaries, inhibits (stops) FSH production and increases LH production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What controls the menstrual cycle?

A

Hormones control the menstrual cycle (oestrogen; progesterone; LH; and FSH)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the 4 hormones involved in maintaining the menstrual cycle?

A

Oestrogen

Progesterone

LH

FSH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the function of the hormone FSH, and where is it secreted from?

A

FSH, secreted by the pituitary gland, causes the egg to mature and stimulates the ovaries to produce oestrogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How are hormones used to control fertility?

A

FSH is used to increase fertility

The ‘pill’ prevents FSH (so preventing pregnancy)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

How can FSH be used to control fertility?

A

FSH can be given to women who want to get pregnant but are having difficulty

FSH increases the number of mature eggs, increasing the likelihood of becoming pregnant and mature eggs can be collected for IVF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

How does the contraceptive pill work?

A

Oestrogen and progesterone are used to stop FSH production, stopping any eggs maturing, preventing pregnancy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are the possible problems with using FSH for fertility treatment?

A

FSH can lead to multiple eggs being released, resulting in multiple offspring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What does a healthy diet consist of?

A

A balance of: -

Carbohydrate

Protein

Fat

Vitamins

Minerals

Fibre

Water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What does malnourished mean and what can this lead to?

A

If you do not eat a healthy balanced diet you will be malnourished – this can lead to deficiency diseases as well as weight problems (too fat / thin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What deficiency diseases are caused by a lack of: -

Iron

Vitamin C

Vitamin D

A

Iron → anaemia

Vitamin C → scurvy

Vitamin D → rickets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What health problems are linked to a lack of food?

A

Reduced resistance to infection / irregular periods

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is metabolic rate and what affects it?

A

Metabolic rate is the rate at which the chemical reactions occur within the cells – this is affected by exercise, proportion of muscle to fat and genetic makeup

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What may cause people to need less food?

A

Less exercise / warmer climate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

How does exercise affect your metabolic rate?

A

Metabolic rates stay high for some time after exercise

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What diseases are linked to obesity?

A

Arthritis

Diabetes (type II)

High blood pressure

Heart disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What is arthritis?

What is diabetes?

A

Arthritis – wearing of the joints

Diabetes – high blood sugar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What type of lipoproteins are ‘bad’ cholesterol?

A

LDLs – low-density lipoproteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Where is cholesterol made?

A

Liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What affects the level of cholesterol in the blood?

A

Diet and inherited features

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What are the health risks associated with too much cholesterol?

A

Diseases of the heart and blood vessels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What are the 2 types of lipoprotein that carry cholesterol in the blood?

A

LDLs – low-density lipoproteins

HDLs – high-density lipoproteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

How is cholesterol carried in the blood?

A

As lipoproteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Which type of fat increases the level of cholesterol in your blood?

A

Saturated fats

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Which type of fat can reduce the blood cholesterol levels and improve the balance of LDLs and HDLs?

A

Monounsaturated and polyunsaturated fats

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Why is too much salt bad for you?

A

Increased blood pressure for ~30% of the population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Which types of food contain high levels of fat and salt?

A

Processed foods

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What are statins used for?

A

Lowering the risk of cardio-vascular disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What is a drug?

A

A substance, which affects the way the body or mind functions – the affects can be positive or negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

How are drugs tested before they are prescribed to patients?

A

Tested in labs on cells and tissues / on animals and human volunteers / in clinical trials with a small dose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

What was thalidomide developed to treat, what were its side effects and what is it now used to treat?

A

Developed as a sleeping pill but not tested during pregnancy – leads to offspring with limb abnormalities. Now affective treatment for leprosy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

What are withdrawal symptoms and why do people suffer from these?

A

Withdrawal symptoms are experiences when an individual stops taking a drug – these are suffered as the body has become dependent on the drug (the drug has affected the body chemistry of the individual)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What dangerous substances are found in cigarettes?

A

Nicotine → addictive

Carcinogens → cancer causing

Tar → coats lungs

Carbon monoxide → reduces oxygen carried within blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What is a carcinogen and where are these found?

A

Carcinogens are chemicals, which cause cancer – found within cigarettes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

How can smoking when pregnant affect the baby?

A

Smoking can deprive the foetus of oxygen and lead to a low birth weight

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What is carbon monoxide and what affect does it have on the body?

A

Carbon monoxide is a poisonous gas, which reduces the ability for the red blood cells to carry oxygen around the blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

How does alcohol affect the body and what are the long-term effects?

A

Alcohol affects the nervous system and slows reaction times

Long-term effects include sclerosis of the liver and brain damage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What did Semmelweiss do to help prevent the spread of disease in hospitals?

A

Semmelweiss realised the link between hygiene and infection rates – he prevented many deaths by insisting hospital workers washed their hands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

What is a pathogen and what are the 3 main types?

A

A pathogen is a microbe, which causes infectious diseases: bacteria, viruses and fungi

59
Q

How do bacteria make you ill?

A

They reproduce rapidly inside the body and may produce toxins (poisons) making us feel ill

60
Q

How do viruses make you ill?

A

They reproduce inside our body cells, causing damage to the cells they reproduce in

61
Q

How do white blood cells help to protect you against disease?

A

White blood cells ingest pathogens (produce antibodies which destroy bacteria and produce antitoxins to counteract the toxins)

62
Q

What is an antibody and how do they help fight infections?

A

Antibodies are produced by the white blood cells – they clump pathogens together (they also ‘remember’ the pathogens so they can fight them much quicker if an infection occurs again)

63
Q

How can painkillers help during an infection?

A

Painkillers treat the symptoms (i.e. a headache) but do not kill the pathogen

64
Q

How may a viral infection be treated by a doctor?

A

Antiviral medications (hard to develop) and painkillers are prescribed

65
Q

What are antibiotics used to treat?

Give an example of an antibiotic

A

Antibiotics treat bacterial infections

Penicillin

66
Q

Why are antibiotics not used to treat the flu?

A

Flu is a virus – antibiotics have no affect (they only treat bacterial infections)

67
Q

Why are antiviral drugs hard to develop?

A

Viruses mutate (change) resulting in the antiviral medication no longer working

68
Q

How have antibiotic resistant bacteria evolved?

Give an example

A

Natural selection – antibiotics kill most bacteria, but some survive and reproduce into antibiotic resistant bacteria, e.g. MRSA

69
Q

What are we doing to prevent the evolution of more antibiotic resistant bacteria?

A

Prescribing less antibiotics / improving hygiene within hospitals

70
Q

How does a vaccination work?

A

A small amount of dead or weakened microbe is injected – white blood cells make antibodies and the individual is now immune

71
Q

What is immunity?

A

Immunity means you cannot ‘catch’ a disease

72
Q

Give an example of a vaccination

A

MMR

Polio

Tetanus

73
Q

What does the MMR vaccination protect against?

A

Measles, mumps and rubella

74
Q

How may you become immune to a disease?

A

Catching the disease (and surviving) / vaccinations

75
Q

In the menstrual cycle what happens at day 1-5 and then at day 14?

A

Day 1-5 – lining of the uterus breaks down (period)

Day 14 – ovulation (egg released)

76
Q

What is insulin used to treat?

A

Diabetes

77
Q

Which hormone controls the maturation of the egg?

A

FSH

78
Q

Which hormone stimulates the lining of the uterus to thicken?

A

Oestrogen

79
Q

What is homeostasis?

A

Controlling the bodies internal environment

80
Q

What 7 nutrients are needed for a healthy diet and what are they used for?

A

Carbohydrate – energy

Protein – growth and repair

Fat – insulation

Vitamins – chemical reactions

Minerals – chemical reactions

Fibre – aid digestion

Water – chemical reactions

81
Q

What is the normal body temperature?

A

37°C

82
Q

What is the difference between saturated and unsaturated fat?

A

Saturated – fat saturated with hydrogen

Unsaturated – fat not saturated with hydrogen

83
Q

What diseases are associated with smoking?

A

Lung cancer

Throat cancer

Emphysema

Heart disease

84
Q

What is meant by a ‘gateway’ drug?

Give an example

A

A drug, which may lead to the use of harder drugs – e.g. cannabis

85
Q

What is the addictive substance in a cigarette?

A

Nicotine

86
Q

What is an epidemic?

What is a pandemic?

A

Epidemic – a disease spread around a local area

Pandemic – a disease spread around the world

87
Q

Why are viral infections often more contagious than bacterial infections?

A

Viruses are small enough to be transferred in water droplets within the air

88
Q

How does smoking affect the ciliated cells and what affects can this have on health?

A

Cells become damaged, causing smokers to cough regularly

89
Q

What is the definition for the following symbol: -

A

Biohazard - (biological hazard) – a biological substance which poses a threat to the health of living organisms, primarily that of humans

90
Q

How are micro-organisms grown?

A

Sterilise the culture medium and petri-dish (done in an autoclave)

Use sterile inoculating loops (pass through a flame) to transfer micro-organisms

Seal the dish with adhesive tape to prevent micro-organisms from the air contaminating the sample / culture

91
Q

Why are micro-organisms not grown at temperatures above 25oC in school laboratories?

A

To reduce the risk of pathogens growing which might harm humans

92
Q

Why does industry grow micro-organisms above 25oC

A

In industrial conditions higher temperatures can produce more rapid growth (although the risks are increased of growing pathogens potentially harmful to humans)

93
Q

What is a tropism and what are geotropism, hydrotropism and phototropism?

A

Plants respond to stimuli by growing to or away from them – a growth movement in response to a stimulus is a tropism (towards stimulus = positive tropism, away from stimulus = negative tropism)

Geotropism – gravity

Hydrotropism – water

Phototropism - light

94
Q

What do auxins do?

A

Auxins are plant hormones that make some parts of a plant stem grow faster than others (controlling geotropism and phototropism)

95
Q

What is rooting powder?

A

Rooting powder contains plant growth hormones – dip a cutting into rooting powder and the plant hormones stimulate the cutting to grow new roots

96
Q

What are statins?

A

Statins are drugs which potentially reduce the risk of heart attacks and strokes – they do this by lowering the level of cholesterol in the blood

97
Q

What is doping?

A

Athletes who use performance enhancing drugs

98
Q

What do stimulants do?

A

They make athletes more alert and mask fatigue

99
Q

What do steroids do?

A

They help athletes train harder and build up muscles

100
Q

What do beta blockers do?

A

They help athletes keep their heart rate low and reduce tremble in the hand

101
Q

What is the function of the hormone LH in the menstrual cycle?

A

LH stimulates the release of an egg from the ovary

102
Q

What is cannabis?

A

Cannabis is an illegal drug which contains chemicals which may cause mental illness

103
Q

How are these animals adapted to their surroundings: -

Polar bear

Camel

Cactus

A

Polar bear: white coat (camouflage); thick coat & small SA: volume (warmth); high body fat levels

Camel: hump (fat store); wide feet (reduce sinking into sand)

Cactus: spines (protection & reduced transpiration); long roots (increase water uptake); low leaf surface area

104
Q

What do plants compete for?

What do animals compete for?

A

Plants – light; water; nutrients (from soil); space

Animals – food; mates; territory

105
Q

What is a gamete and what do they carry?

A

Gametes are the sex cells (e.g. sperm and egg), which carry genetic information

106
Q

What is a gene?

A

A gene is a section of DNA, coding for the development of one characteristic

107
Q

Where is DNA carried in most cells?

A

In the nucleus

108
Q

What is sexual and asexual reproduction?

A

Sexual reproduction – require 2x parents producing similar, but not identical offspring (fusing of male and female gametes)

Asexual reproduction – only 1x parent needed producing genetically identical offspring (no gametes so no mixing of genes)

109
Q

How can plants be cloned?

A

Plants can be cloned by taking cuttings (small section of plant is cut off and placed in rooting powder – plant grown is genetically identical to the parent)

110
Q

How can cells be cloned using tissue cultures?

A

A small group of cells are removed and grown in a growth medium (such as agar)

111
Q

How can animals be cloned using embryo transplants?

A

Chosen embryo is split into small bundles of cells at an early stage – bundles are placed into host mother resulting in genetically identical offspring to original embryo

112
Q

How can adult cells be cloned?

A

Nucleus of adult cell removed, and nucleus of ovum removed – original nucleus then inserted into ovum resulting in clone of adult

113
Q

What is genetic engineering and how is it done?

A

Genetic engineering is when the genes of one animal are inserted into another – e.g. human gene cut using enzymes and placed within DNA of bacterium

114
Q

What are the ethical implications of genetic engineering?

A

Should we be playing God?

There has been no long-term testing

115
Q

What are the ethical considerations involved in cloning?

A

If we reduce the gene pool we may become more susceptible to diseases

Should we be allowed to clone organs / whole organisms?

116
Q

What are GM crops and what concerns are associated with them?

A

GM crops have been genetically engineered to have the best genetic makeup (e.g. resistant to specific diseases) increasing yields

There is concern on the effect of wild flowers and insects as well as uncertainty on human health when GM crops are consumed

117
Q

Why can scientists not be certain how life began on Earth?

A

We were not there / we cannot reproduce spontaneous life

118
Q

How did Darwin suggest animals and plants evolved from simple organisms?

A

Simple organisms evolved through natural selection (more than 3 billion years ago): -

One organism has an advantage (mutation / change in environment)

Organism now more likely to survive

Organism more likely to breed and pass on their advantageous genes

119
Q

What are the differences between the ideas suggested by Darwin and Lamarck?

A

Darwin suggested genetic information was passed from parent to offspring

Lamarck suggested environmental factors (causing changed in an organisms lifetime) were passed on, e.g. a giraffe stretches for food so their offspring’s necks and bodies become larger

120
Q

What evidence is there for the theory of evolution?

A

Fossil records show how animals have changed over time

DNA and physiological similarities

121
Q

What is the theory of evolution?

A

That all organisms on Earth have evolved from simple single celled organisms millions of years ago

122
Q

What may cause an organism to become extinct?

A

New diseases

Changes to the environment

New predators

New competitors

123
Q

How does natural selection lead to evolution?

A

Organisms evolved through natural selection: -

Variation where one organism has an advantage (mutation / change in environment)

Organism now more likely to survive

Organism more likely to breed and pass on their advantageous genes

124
Q

What is a mutation and what can it lead to?

A

A mutation is a change in DNA – this can lead to a negative change / neutral change / positive change (leading to evolution)

125
Q

What are the impacts caused by our rapidly increasing population?

A

Raw materials are being used up (including non-renewable energy resources); more waste; and more pollution

126
Q

How does the rapidly increasing human population reduce the land available for animals?

A

Building / quarrying / farming / waste

127
Q

How can an increase in human waste pollute the Earth?

A

Water: sewage; fertilisers and toxic chemicals

Air: smoke; gases (sulfur dioxide (acid rain))

Land: toxic chemical (pesticides and herbicides which can be washed from land to water)

128
Q

Which organisms can be used as indicators of pollution?

A

Lichens: air pollution indicators (particularly SO2)

Invertebrates: water pollution indicators varying in species found due to differing amounts of O2 in the water

129
Q

What is the equation for photosynthesis?

A

light

6CO2 + 6H2O → C6H12O6 + 602

130
Q

Why is energy needed for photosynthesis and how does a plant obtain this energy?

A

Energy is needed to convert carbon dioxide and water into sugar (glucose)

The energy is light energy – this is trapped by the chlorophyll in the chloroplasts

131
Q

What happens to the mass of living material (biomass) as you go up the stages of a food chain?

A

It is reduced

132
Q

What is a pyramid of biomass?

A

The biomass at each stage is drawn to scale and shown as a pyramid

133
Q

What happens to the energy as you move up the stages of a food chain?

A

It is reduced

134
Q

How can food production be made more energy efficient?

A

If the stages in the food chain are reduced less energy is lost

135
Q

Why is the energy and biomass reduced as you move up the stages of a food chain?

A

Energy is lost due to: -

Some materials and energy are lost by the organism as waste

Energy is used for movement etc… (lost to the surroundings)

Mammals and birds maintain a constant temperature, which is usually higher than the surroundings

136
Q

Why do materials decay?

A

They are broken down (digested) by microorganisms and returned to the environment

137
Q

What conditions do materials decay fastest in?

A

Warm

Moist

Oxygen rich

138
Q

Draw a diagram of the carbon cycle

A

Carbon Cycle

139
Q

Why is the decay process so important to food chains?

A

Decay releases substances, which plants need to grow

140
Q

Explain the carbon cycle

A

CO2 is removed by photosynthesis (used to make carbohydrates, fats and proteins)

Some CO2 is returned by respiration of the plants

Animals eat plants, and the carbon becomes part of the fats and proteins, which make up the animal

Plants and animals die – microorganisms feed on them, respiring as they do, returning some carbon

141
Q

Plants remove carbon dioxide from the environment during photosynthesis – what do they use this to make?

A

Carbon dioxide is needed for carbohydrates, fats and proteins (which make up the plant bodies)

142
Q

What are extremophiles?

A

Organisms that live in very extreme environments, e.g. high temperature / pH / pressure / salinity

143
Q

What is eutrophication, how is it caused and what are the associated dangers?

A

Eutrophication occurs when excess nitrates make their way into rivers causing algae growth

Some plants then start dying due to increased competition for light which result in micro-organisms decomposing them (which respiring, using oxygen)

The lack of oxygen causes larger organisms such as fish to die

144
Q

Why was the theory of natural selection only gradually accepted?

A

Natural selection challenged the idea of God – initially there was thought to be insufficient evidence (this was subsequently found ~50 years after publication)