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SCIENCE > Biology paper 1 (complete) > Flashcards

Biology paper 1 (complete) Flashcards

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1
Q

B4: Write down the word equation for photosynthesis.

A

Carbon dioxide + Water –> Oxygen + Glucose

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2
Q

B4: symbol equation for photosynthese

A

6C02 + 6H20 –>

C6H12O6 + 6O2

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3
Q

B4 ; Photosynthesis is affected by limiting factors.

What is meant by the term ‘limiting factor’?

A

A factor which is not at an optimum level to enable maximum rate
of photosynthesis e.g. temperature

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4
Q

B4 : Name the raw materials needed by a plant for photosynthesis?

A

Carbon dioxide and water

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5
Q

B4: Name the green pigment present in plant cells.

What is the role of this green pigment?

A

Chlorophyll.

To transfer energy from the environment and use it to synthesise glucose from carbon dioxide and water.

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6
Q

B4: List three ways commercial farmers improve the environmental conditions in large greenhouses to maximise photosynthesis and ensure they make a profit.

A

Increase the air temperature with heaters.
Provide artificial lighting to supplement the sunlight and through the night.
Increase the amount of carbon dioxide in the atmosphere.

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7
Q

B4 :List three ways glucose produced by photosynthesis is used in plants?

A

Used for respiration; used to produce fats or oils for storage; used to produce amino acids for protein synthesis; converted into insoluble starch for storage; used to produce cellulose to strengthen cell walls.

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8
Q

B4: Light intensity formula

A

Light Intensity α 1/ distance2

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9
Q

B4: When does respiration occur in cells?

A

Continuously

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10
Q

B4: Aerobic respiration

A

needs oxygen
end products: carbon dioxide + water
oxidation of glucose is complete
efficiency of energy is high

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11
Q

B4: Anaerobic respiration in animal cells

A

does not need oxygen
end products: lactic acid
oxidation of glucose is =incomplet
efficiency of energy is low

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12
Q

B4: Anaerobic respiration in plant and yeast cells

oxygen?
end products?
oxidation of glucose?
efficiency?

A

does not need oxygen
end products: lactic ethanol and carbon dioxide
oxidation of glucose is IncompletE
efficiency of energy is low

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13
Q

B4: Name three processes that organisms require energy for.

A

Chemical reactions to build larger molecules, keeping warm and movement.

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14
Q

B4: What does the chemical formula C6H12O6 represent?

A

Glucose

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15
Q

B4: rite down the word equation for aerobic respiration in a plant cel

A

glucose + oxygen carbon dioxide + water

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16
Q

B4: Write down the word equation for anaerobic respiration in a yeast cell.

A

glucose –> carbon dioxide + ethanol

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17
Q

B4: Why is fermentation of economic importance?

A

Used in the manufacture of bread and alcoholic drinks.

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18
Q

B4: Describe three ways in which the body responds to vigorous exercise in order to ensure sufficient oxygen reaches the muscle cells.

A

Increase in heart rate; increase in breathing rate and increase in breath volume.

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19
Q

B4: If exercise carries on for a long time, what happens to the muscles?

A

Muscles become fatigued and stop contracting efficiently.

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20
Q

B4: Why is respiration described as an exothermic reaction?

A

Respiration is an exothermic reaction because it transfers energy to the environment.

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21
Q

What is the definition of metabolism?

A

Metabolism is the sum of all reactions which occur in a cell or body.

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22
Q

What are the following made from:

a) carbohydrates
b) lipids
c) proteins

A

a) many glucose molecules
b) 1 molecule of glycerol and 3 molecules of fatty acid
c) many amino acids

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23
Q

Describe the process for removing lactic acid from the body.

A

Blood flows through the muscle cells and transports the lactic acid
to the liver where it is converted back into glucose. The glucose is
then used in aerobic respiration or stored as glycogen

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24
Q

B4: What is meant by the oxygen debt?

A

The amount of extra oxygen which is needed to remove all lactic
acid from the body is known as the oxygen debt.

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25
Q

B3: What is the definition of a pathogen?

A

Micro-organisms which cause infectious disease in animals & plants.

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26
Q

List four types of micro-organism which can act as pathogens.

A

Bacteria, Virus, Protist, Fungus.

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27
Q

What do pathogens need from the host organism?

A

Suitable conditions and nutrition to be able to grow and reproduce.

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28
Q

How can HIV be controlled

A

HIV can be successfully controlled with antiretroviral drugs. If the
immune system is badly damaged then AIDS may develop.

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29
Q 
Measles
symptom
method of transmission
control spread by
caused by
A

Measles

Fever
Red skin rash

Droplet infection
from sneezes and
coughs

Child Vaccination

Virus

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30
Q 
Salmonella
symptom
method of transmission
control spread by
caused by
A

Fever, cramp,
vomiting, diarrhoea

Food prepared in
unhygienic
conditions or not
cooked properly

Improve food hygiene, wash
hands, vaccinate poultry,
cook food thoroughly

Bacteria

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31
Q 
rose black spot
symptom
method of transmission
control spread by
caused by
A

Purple black spots
on leaves

Spores carried
via wind/water

Remove infected leaves and spray
with pesticide

Fungus

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32
Q 
gonorrhoea
symptom
method of transmission
control spread by
caused by
A

Green discharge
from penis or
vagina

Direct sexual contact
or body fluids

Use of a condom and treat
infected person with antibiotics

Bacteria

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33
Q 
malaria
symptom
method of transmission
control spread by
caused by
A

Recurrent fever By a vector from an
infected person

Preventing breeding of mosquitoes
or use of a net to prevent being
bitten

Protist

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34
Q 
TMV
symptom
method of transmission
control spread by
caused by
A

Mosaic pattern on
leaves

wounds in
epidermis caused
by pests

Remove infected leaves and
control pests which are
damaging leaves

Virus

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35
Q

Suggest how pathogens could be transferred in this situation.
What could people do to reduce the spread of pathogens?

A

Direct contact by
touching a
contaminated
surface.

Droplet infection if
someone sneezes or
coughs in the lift.
Air - if fungal spores
are present.
Could reduce the
spread by:
Hand over mouth if
coughing and then
washing.
Use a tissue if sneezing
and then dispose of it
and wash hands.
Washing hands with
soap after visiting the

toilet.

Wear a face mask.

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36
Q

Name and describe 3 ways the human body defends against the

entry of pathogens.

A

Skin – barrier, nose - nasal hairs , mucus and cilia,
trachea & bronchi – mucus to catch, cilia to remove from lungs,
stomach - HCl acid kills.

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37
Q

What is an antigen?

A

A protein on the surface of a pathogen.

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38
Q

Why will the antibody produced for measles not be effective in other
diseases?

A

Antibody has a specific shape which fits with a specific

antigen.

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39
Q

Why are dead or inactive pathogens used in a vaccine?

A

To stimulate white blood cells to make antibodies without causing the
disease.

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40
Q

What happens if the live pathogen invades the body after being
vaccinated?

A

White blood cells able to respond much faster and produce more
antibodies quicker to destroy the pathogens so the person doesn’t
suffer the symptoms of the disease.

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41
Q

What is an antibiotic and what is it used for?

A

Kills bacteria inside the body without harming human cells.

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42
Q

Why is there a growing concern about bacterial resistance to

antibiotics?

A

The resistant bacteria are not killed and can continue to
multiply inside the body making the person very ill and infecting
others too.

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43
Q

Which one of these statements is true?
Painkillers are used to treat the symptoms of a disease and kill the
pathogens which cause it
Painkillers are used to kill the pathogens causing a disease

A

Painkillers are used to treat the symptoms of a disease but do not kill
the pathogens.

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44
Q 
Any potential new drug has to go through a series of tests.
What is meant by the following terms?
a) efficacy
b) toxicity
c) optimum dose
A

a) Efficacy how effective the drug is
b) Toxicity how poisonous the drug is
c) Optimum dose minimum amount of the drug which provides
the best response

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45
Q

the process of drug testing.

A
  1. Drugs are trialled in laboratories on cells and tissue cultures
  2. Drugs are trialled on live animals
  3. Drugs are trialled on healthy volunteers
  4. Drugs are trialled on people with the disease the drug is for
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46
Q

What is a placebo and why is it used?

A

A medicine that does not contain the drug that is being trialled.

A placebo is used to check that there are no other factors which
may cause the patient‘s condition to improve without the drug.

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47
Q

how monoclonal antibodies are produced.

A
  1. Mouse is injected with a pathogen.
  2. Mouse lymphocytes produce antibodies.
  3. Mouse lymphocytes are collected.
  4. Mouse lymphocyte and mouse tumour cell are fused.
  5. Hybridoma cells are separated and cultured to form a clone.
  6. The clone produces large quantities of antibody.
  7. The antibodies are collected and purified.
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48
Q

What are the applications of monoclonal antibodies?

A

Pregnancy testing

Used to measure levels of hormones and other chemicals in blood

Treat some cancers by delivering a toxic drug to the cancer cells

To find various molecules in cells or tissues by binding to them with a
fluorescent dye

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49
Q

Why do some people feel the use of monoclonal antibodies is unethical?

A

Mouse has to suffer the disease deliberately

Mouse is induced to have cancer

Treatment not always safe

It’s very expensive and money could be better used

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50
Q

Name 3 ways you can detect that a plant is diseased.

A

leaf spots/discolouration, growths, malformed stems or leaves, presence of pests,
stunted growth, areas of decay (rot)

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51
Q

Type of plant defence used
what is the plant being defended against
describe the defence being used

A

Mechanical
Herbivores eating it Thorns or hairs

Chemical Pathogens/bacteria
Herbivores/animals
The chemical released is
antibacterial or poisonous

Physical
Herbivores and
pathogen entry
Dead bark coating which falls off

Physical 
Insects such as
aphids
Waxy cuticle/cellulose cell
walls are hard to penetrate
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52
Q

Describe why nitrate ions are very important for plants.

A

Nitrate is crucial for protein synthesis and hence growth. Without
sufficient nitrate ions, the plant would be stunted.

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53
Q

What is chlorosis and how can it be prevented?

A

Chlorosis is the yellowing of the leaves. It can be prevented by
providing the plant with magnesium.

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54
Q

B3: Why would a test kit containing monoclonal antibodies be useful to
detect plant disease?

A

The monoclonal antibodies can be used to detect a particular
chemical which is only present in one type of pathogen. This would
then show whether the plant was infected with this disease or not.

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55
Q

B2: Put the following in order of size from the smallest to the largest:
organ organism cell tissue organ system

A 
cell  
tissue  
organ  
organ system 
 organism
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56
Q

B2: Define each of the words:

a) organism
b) organ system
c) organ
d) tissue
e) cell

A

Organism - A group of organ systems working together.
Organ system - A group of organs working together to perform a
specific function.
Organ - A group of tissues working together to perform a specific
function.
Tissue - A group of similar cells with a similar structure and function.
Cell - The smallest structural and functional unit of an organism.

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57
Q

B2: What is digestion?

A

Large insoluble molecules are broken down into

smaller soluble ones.

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58
Q

B2: What is an enzyme?

A

A biological catalyst – they speed up the rate of

reaction without being used up.

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59
Q

Amylase

A

Produced in
Salivary glands and
pancreas

Breaks carbohydrates into simple sugars

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60
Q

Protease

A

produced in Stomach and
pancreas

breaks proteins into amino acids

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61
Q

lipase

A

produced in pancreas

breaks Fats and oils (lipids) into fatty acids and glycerol

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62
Q

What biological molecule are enzymes made of?

A

proteins

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63
Q

What is the active site of an enzyme?

A

It is where the substrate binds.

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64
Q

What is a substrate?

A

Substance (chemical) that the enzyme acts on.

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65
Q

What are the products of digestion used for in the body?

A

They are used
to build new carbohydrates, lipids and proteins in the body. Glucose is
used in respiration.

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66
Q

What does denatured mean?

A

That the active site of the enzyme has

changed shape so the substrate cannot fit.

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67
Q

How does increasing the temperature affect enzyme activity?

A

Initially it
increases the rate of reaction due to increased collisions between the
enzyme and substrates, if the temperature is too high the enzyme will
denature.

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68
Q

How does pH affect enzyme activity?

A

Enzymes have optimum pH

conditions, if these are too alkaline or acidic the enzyme denatures

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69
Q

What is the role of bile in digestion?

A

It neutralises stomach.

(hydrochloric) acid and emulsifies fats.

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70
Q

Where in the body is bile made?

A

Bile is made in the liver and stored

in the gall bladder.

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71
Q

What is a double circulatory system?

A

Where blood from the heart is

pumped to the lungs and the body at the same time.

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72
Q

What is a pacemaker?

A

A group of cells in the right atrium that controls

the heart rate.

73
Q

What is the role of the coronary arteries?

A

To supply oxygenated blood

to the heart muscle.

74
Q

Where does the left atrium pump blood to?

A

To the left ventricle.

75
Q

Where does gas exchange take place in the lungs?

A

In the alveoli.

76
Q

Name the gas that moves from the blood into the lungs

A

carbon dioxide

77
Q

Name the blood vessels that carry blood away from the heart

A

Arteries.

78
Q

Which blood vessels are only one cell thick?

A

capillaries

79
Q

Which blood vessels have thick muscular walls?

A

arteries

80
Q

Which blood vessels have valves?

A

veins

81
Q

What is plasma?

A

The pale yellow fluid part of blood, it transports
cells, CO2

, hormones and waste.

82
Q

What is the role of a red blood cell?

A

To carry oxygen around the

body.

83
Q

In what two ways can white blood cells fight infection?

A

They can
produce antibodies that destroy microbes or they can engulf
microbes.

84
Q

What is the role of platelets?

A

They form clots to reduce bleeding.

85
Q

What is coronary heart disease?

A

Where layers of fatty material build

up inside the coronary arteries narrowing them.

86
Q

What are the risk factors for coronary heart disease?

A

Smoking, high

blood pressure, high cholesterol and not enough exercise.

87
Q

What is a stent?

A

A metal cylinder grid that is inserted into an artery

to keep the artery open.

88
Q

What are statins?

A

Drugs that reduce the harmful cholesterol in the

blood

89
Q

What is the role of heart valves?

A

To stop the blood in the heart from

flowing in the wrong direction.

90
Q

Give two faults that can occur with heart valves.

A

They may not open

fully or develop a leak.

91
Q

What treatment can be given to a person with faulty heart valves?

A

They can have their heart valves replaced (biological or mechanical).

92
Q

Name three conditions that can lead to heart failure.

A

Atherosclerosis

CHD), cardiomyopathy, congenital heart disease (born with it

93
Q

Define the word health.

A

A state of complete physical and mental well-being

and not merely the absence of disease or infirmity.

94
Q

What are communicable diseases?

A

Infectious diseases caused by microbes

that can be spread.

95
Q

What are non-communicable diseases?

A

Diseases not caused by infections and

cannot be spread.

96
Q

Name 4 ways that different types of disease can interact to make a person ill.

A

Defects in the immune system, viruses that can trigger cancer, immune
reactions caused by pathogens, physical ill health.

97
Q

List some human costs of non-communicable diseases

A

Lower quality of life,

shorter life span.

98
Q

List some financial costs of non-communicable diseases

A

Healthcare costs,

reduced income, buying of specialist equipment.

99
Q

Name two other risk factors that affect health

A

Lifestyle and substances taken

into the body or in the environment.

100
Q

What are the risk factors for cardio vascular disease?

A

Diet, smoking, lack of

exercise.

101
Q

How does alcohol cause liver disease?

A

It causes the liver to

become fatty and this can lead to cirrhosis.

102
Q

What does alcohol damage in the brain?

A

It damages the nerve

cells and the brain mass may shrink.

103
Q

What is COPD?

A

A group of lung diseases that narrow airways

making it difficult for people to move air in and out of the lungs.

104
Q

What is a carcinogen?

A

A substance that can cause cancer.

105
Q

How can carcinogens cause cancer?

A

They damage DNA or speed

up cell division and increase the chance of a mutation occurring.

106
Q

Name four types of carcinogens?

A

Tobacco, alcohol, occupational

carcinogens, ionising radiation.

107
Q

What is a tumour?

A

A mass of cells caused by uncontrolled cell

growth.

108
Q

What are benign tumours?

A

An abnormal growth of cell in a

membrane contained in one area.

109
Q

What are malignant tumours?

A

Cancerous.
An abnormal growth of cells that
invade other tissues and can spread in the body.

110
Q

What is a plant tissue?

A

A group of similar plant cells working

together to carry out a particular function.

111
Q

Epidermal

A

Epidermal

Covers the surfaces of the plant for protection

112
Q

Palisade mesophyll

A

The cells are packed with chloroplasts it is the site of most of

the photosynthesis

113
Q

spongy mesophyll

A

Photosynthesis also occurs in the cells here. Large air spaces

for gas exchange

114
Q

xylem and phloem

A

Form vascular bundles and transport water, mineral ions and

glucose around the plant

115
Q

meristem

A

Found at the tips of roots and shoots. Where cell

differentiation occurs

116
Q

what is the role of the leaf organ

A

Photosynthesis and respiration.

117
Q

What is the role of the guard cells?

A

To open and close to let gases

diffuse in and out through the stoma.

118
Q

What is a plant organ?

A

A group of plant tissues working together to

carry out a particular function.

119
Q

Name the organs in the plant organ system that transports

substances around the plant.

A

Stem, leaf and root.

120
Q

What is the role of the root hair cell?

A

To take in water and mineral

ions from the soil.

121
Q

What is transpiration?

A

The movement of water and mineral ions

from the roots to the stems and leaves.

122
Q

What is translocation?

A

The movement of dissolved sugars from the

leaves to the rest of the plant for immediate use or storage.

123
Q

What factors increase the rate of transpiration?

A

Increased

temperature, humidity, air movement and light intensity.

124
Q

B1: Where is the genetic material in a prokaryotic cell?

A

In a bacterial DNA loop and there may be one or more plasmid rings.

125
Q

Where is the genetic material in a eukaryotic cell?

A

The DNA is in chromosomes enclosed in a nucleus.

126
Q

Units

A

milli (mm) - 0.001m
micro - 0.000 001m
Nano (nm) -0.000 000 001m

127
Q

Sperm

A

Function is to fertilise an egg.

• Streamlined with a long tail to swim to the egg.
• Acrosome in the head containing enzymes to
digest the egg cell membrane.
• Large number of mitochondria in the mid section
to release energy for movement.

128
Q

nerve cell

A

Function is to carry electrical signals.
• Long to carry signals long distances.
• Branched connections to connect to other nerve
cells and form a network around the body.
• Insulating sheath to enhance transmission of
electrical signals.

129
Q

muscle cell

A

Function is to contract to allow movement.
• Contain a large number of mitochondria to
release energy from respiration for movement.
• Long so that there is enough space to contract.

130
Q

Root hair cell

A

Function is to absorb water and minerals from the

soil.
• Hair like projections to increase the surface area.
(Note that root hair cells have no chloroplasts this is
because they do not need them as they are in the soil)

131
Q

xylem cell

A

Function is to carry water and minerals in plants.
• Form hollow xylem tubes made of dead tissue.
• Long cells with walls toughened by lignin.
• Water and minerals flow from the roots towards the
leaves only in one direction in a process called
TRANSPIRATION.

132
Q

phloem cell

A

Function is to carry glucose around the plant.
• Form phloem tubes made of living tissue.
• Cells have end plates with holes in them.
• Glucose in solution moves from the leaves to growth
and storage tissues in a process called
TRANSLOCATION.

133
Q

What does cell differentiation mean?

A

When a cell changes to become specialised.

134
Q

In what stage of an animal’s life cycle do most cells differentiate?

A

In the early stages.

135
Q

In mature animals when do cells still need to differentiate?

A

For repair and replacement of cells.`

136
Q

In what stage of their life cycle do plant cells differentiate?

A

They differentiate throughout their lifecycle.

137
Q

Define the term resolution.

A

The shortest distance between two objects that can be seen clearly.

138
Q

What are the advantages of the electron microscope?

A

Electron microscopes
have a higher magnification and resolution than light microscopes; scientists
can see more sub-cellular structures.

139
Q

A magnified cell structure has a diameter of 375μm.
The actual diameter of the structure is 2.5μm.
Calculate how many times the structure has been magnified.

A

M = I/A M = 375/2.5 = 150 M = 150 times

140
Q

Describe how you would make an onion cell slide.

A

• Place thin section of onion epidermis onto slide.
• Place a drop of iodine in the middle of the slide to stain the onion.
• Gently lower cover slip onto the onion without trapping air
bubbles.
• Soak up any excess liquid with a paper towel.

141
Q

Describe how you would use the light microscope to view onion
cells.

A

• Switch on the light source and place your slide on the stage.
• Use the lowest objective lens and turn the focusing wheel to move
the lens close to the slide.
• Slowly adjust the focusing wheel until you can see a clear image.

• Increase the magnification by changing the objective lens and re-
focus.

142
Q

What is ‘binary fission’?

A

Cell division where two identical cells to the

parent cell are formed.

143
Q

Why do you need to sterilise Petri dished and culture mediums before
use?

A

To kill any unwanted microorganisms.

144
Q

What would you use an inoculating loop for?

A

To transfer bacteria onto

the agar.`

145
Q

How do you sterilise an inoculating loop?

A

By heating in a Bunsen flame.

146
Q

How would you secure the lid of the Petri dish?

A

With tape but not sealed

all the way around.

147
Q

What temperature would you incubate the samples at in a school and
why should you use this temperature?

A

25oC, to prevent the growth of

pathogens harmful to humans.

148
Q

How can you test the effectiveness of antibiotics and disinfectants on
bacteria?

A

Inoculate agar with bacteria, place discs soaked in the solutions
(water as a control) and place the discs on the agar containing bacteria.
Incubate at 25oC.

149
Q

What are chromosomes?

A

Coiled strands of DNA molecules.

150
Q

What is a gene?

A

A section of DNA that codes for a protein.

151
Q

What is DNA?

A

A genetic material found in the nucleus that codes for proteins.

152
Q

Where in a cell do you find chromosomes?

A

In the nucleus of cells.

153
Q

How many chromosome pairs do you find in a human body cell?

A

23 pairs

154
Q

What are the three stages of the cell cycle?

A

Growth, DNA synthesis

and mitosis.

155
Q

What is mitosis and what is it used for in animals and plants?

A

Growth, repair and asexual reproduction.

156
Q

What is a stem cell?

A

An undifferentiated cell.

157
Q

Which type of human stem cell can differentiate into any human
cell?

A

Embryo stem cells.

158
Q

What is therapeutic cloning?

A

Where patients are given stem cells

containing the same genes as theirs.

159
Q

What are the risks of therapeutic cloning?

A

Viral infections.

160
Q

State two reasons why people may object to the use of stem cells
in therapeutic cloning.

A

Ethical and religious reasons.

161
Q

What are meristems?

A

Structures in plants that contain stem cells.

162
Q

State two reasons that plants are cloned?

A

To clone rare species of

plants and to clone crop plants with useful characteristics.

163
Q

Define ‘diffusion’?

A

The spreading of the particles from a region where they are of a
higher concentration to an area of lower concentration.

164
Q

State three places where diffusion occurs in the body.

A

Small

intestines, lungs, kidneys

165
Q

What is a concentration gradient?

A

The difference in concentration

between two areas next to each other.

166
Q

What three factors affect rate of diffusion?

A

Concentration gradient,

temperature, surface area.

167
Q

What is surface area to volume ratio?

A

The size of a surface

compared to its volume.

168
Q

Diffusion: The small intestines.

A

Have villi to increase surface area, good

blood supply, thin membranes.

169
Q

diffusion: the lungs

A

Have alveoli to increase surface area, good blood

supply, thin membranes, they are ventilated.

170
Q

diffusion: gills in fish

A

Have gill filaments and lamella to increase surface

area, good blood supply, thin membranes.

171
Q

diffusion: roots

A

Have root hair cells to increase surface area.

172
Q

diffusion: leaves

A

Large surface area, thin and stomata.

173
Q

Define osmosis?

A

Osmosis is the diffusion of water from a dilute
solution to a concentrated solution through a partially permeable
membrane.

174
Q

What is a partially permeable membrane?

A

A membrane that lets

some but not all substances through.

175
Q

What happens to an animal cell in a hypertonic solution?

A

It will

lose water by osmosis and shrivel.

176
Q

What happens to an animal cell in a hypotonic solution?

A

It will

absorb water by osmosis and get bigger/burst.

177
Q

Define active transport.

A

Active transport moves substances from a
more dilute solution to a more concentrated solution (against a
concentration gradient) using energy from respiration.

178
Q

Why does active transport need to occur in root hair cells?

A

Because the minerals are at a higher concentration in the roots than in
the soil.

179
Q

Why does active transport need to occur in the gut?

A

Because the

glucose in the blood is at a higher concentration than in the gut.

SCIENCE (5 decks)

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