Biology paper 1 (complete) Flashcards
1
Q
B4: Write down the word equation for photosynthesis.
A
Carbon dioxide + Water –> Oxygen + Glucose
2
Q
B4: symbol equation for photosynthese
A
6C02 + 6H20 –>
C6H12O6 + 6O2
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
4
Q
B4 : Name the raw materials needed by a plant for photosynthesis?
A
Carbon dioxide and water
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.
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.
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.
8
Q
B4: Light intensity formula
A
Light Intensity α 1/ distance2
9
Q
B4: When does respiration occur in cells?
A
Continuously
10
Q
B4: Aerobic respiration
A
needs oxygen
end products: carbon dioxide + water
oxidation of glucose is complete
efficiency of energy is high
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
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
13
Q
B4: Name three processes that organisms require energy for.
A
Chemical reactions to build larger molecules, keeping warm and movement.
14
Q
B4: What does the chemical formula C6H12O6 represent?
A
Glucose
15
Q
B4: rite down the word equation for aerobic respiration in a plant cel
A
glucose + oxygen carbon dioxide + water
16
Q
B4: Write down the word equation for anaerobic respiration in a yeast cell.
A
glucose –> carbon dioxide + ethanol
17
Q
B4: Why is fermentation of economic importance?
A
Used in the manufacture of bread and alcoholic drinks.
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.
19
Q
B4: If exercise carries on for a long time, what happens to the muscles?
A
Muscles become fatigued and stop contracting efficiently.
20
Q
B4: Why is respiration described as an exothermic reaction?
A
Respiration is an exothermic reaction because it transfers energy to the environment.
21
Q
What is the definition of metabolism?
A
Metabolism is the sum of all reactions which occur in a cell or body.
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
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
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.
25
B3: What is the definition of a pathogen?
Micro-organisms which cause infectious disease in animals & plants.
26
List four types of micro-organism which can act as pathogens.
Bacteria, Virus, Protist, Fungus.
27
What do pathogens need from the host organism?
Suitable conditions and nutrition to be able to grow and reproduce.
28
How can HIV be controlled
HIV can be successfully controlled with antiretroviral drugs. If the
immune system is badly damaged then AIDS may develop.
29
```
Measles
symptom
method of transmission
control spread by
caused by
```
Measles
Fever
Red skin rash
Droplet infection
from sneezes and
coughs
Child Vaccination
Virus
30
```
Salmonella
symptom
method of transmission
control spread by
caused by
```
Fever, cramp,
vomiting, diarrhoea
Food prepared in
unhygienic
conditions or not
cooked properly
Improve food hygiene, wash
hands, vaccinate poultry,
cook food thoroughly
Bacteria
31
```
rose black spot
symptom
method of transmission
control spread by
caused by
```
Purple black spots
on leaves
Spores carried
via wind/water
Remove infected leaves and spray
with pesticide
Fungus
32
```
gonorrhoea
symptom
method of transmission
control spread by
caused by
```
Green discharge
from penis or
vagina
Direct sexual contact
or body fluids
Use of a condom and treat
infected person with antibiotics
Bacteria
33
```
malaria
symptom
method of transmission
control spread by
caused by
```
Recurrent fever By a vector from an
infected person
Preventing breeding of mosquitoes
or use of a net to prevent being
bitten
Protist
34
```
TMV
symptom
method of transmission
control spread by
caused by
```
Mosaic pattern on
leaves
wounds in
epidermis caused
by pests
Remove infected leaves and
control pests which are
damaging leaves
Virus
35
Suggest how pathogens could be transferred in this situation.
What could people do to reduce the spread of pathogens?
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.
36
Name and describe 3 ways the human body defends against the
| entry of pathogens.
Skin – barrier, nose - nasal hairs , mucus and cilia,
trachea & bronchi – mucus to catch, cilia to remove from lungs,
stomach - HCl acid kills.
37
What is an antigen?
A protein on the surface of a pathogen.
38
Why will the antibody produced for measles not be effective in other
diseases?
Antibody has a specific shape which fits with a specific
| antigen.
39
Why are dead or inactive pathogens used in a vaccine?
To stimulate white blood cells to make antibodies without causing the
disease.
40
What happens if the live pathogen invades the body after being
vaccinated?
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.
41
What is an antibiotic and what is it used for?
Kills bacteria inside the body without harming human cells.
42
Why is there a growing concern about bacterial resistance to
| antibiotics?
The resistant bacteria are not killed and can continue to
multiply inside the body making the person very ill and infecting
others too.
43
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
Painkillers are used to treat the symptoms of a disease but do not kill
the pathogens.
44
```
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) 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
45
the process of drug testing.
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
46
What is a placebo and why is it used?
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.
47
how monoclonal antibodies are produced.
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.
48
What are the applications of monoclonal antibodies?
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
49
Why do some people feel the use of monoclonal antibodies is unethical?
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
50
Name 3 ways you can detect that a plant is diseased.
leaf spots/discolouration, growths, malformed stems or leaves, presence of pests,
stunted growth, areas of decay (rot)
51
Type of plant defence used
what is the plant being defended against
describe the defence being used
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
```
52
Describe why nitrate ions are very important for plants.
Nitrate is crucial for protein synthesis and hence growth. Without
sufficient nitrate ions, the plant would be stunted.
53
What is chlorosis and how can it be prevented?
Chlorosis is the yellowing of the leaves. It can be prevented by
providing the plant with magnesium.
54
B3: Why would a test kit containing monoclonal antibodies be useful to
detect plant disease?
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.
55
B2: Put the following in order of size from the smallest to the largest:
organ organism cell tissue organ system
```
cell
tissue
organ
organ system
organism
```
56
B2: Define each of the words:
a) organism
b) organ system
c) organ
d) tissue
e) cell
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.
57
B2: What is digestion?
Large insoluble molecules are broken down into
| smaller soluble ones.
58
B2: What is an enzyme?
A biological catalyst – they speed up the rate of
| reaction without being used up.
59
Amylase
Produced in
Salivary glands and
pancreas
Breaks carbohydrates into simple sugars
60
Protease
produced in Stomach and
pancreas
breaks proteins into amino acids
61
lipase
produced in pancreas
breaks Fats and oils (lipids) into fatty acids and glycerol
62
What biological molecule are enzymes made of?
proteins
63
What is the active site of an enzyme?
It is where the substrate binds.
64
What is a substrate?
Substance (chemical) that the enzyme acts on.
65
What are the products of digestion used for in the body?
They are used
to build new carbohydrates, lipids and proteins in the body. Glucose is
used in respiration.
66
What does denatured mean?
That the active site of the enzyme has
| changed shape so the substrate cannot fit.
67
How does increasing the temperature affect enzyme activity?
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.
68
How does pH affect enzyme activity?
Enzymes have optimum pH
| conditions, if these are too alkaline or acidic the enzyme denatures
69
What is the role of bile in digestion?
It neutralises stomach.
| (hydrochloric) acid and emulsifies fats.
70
Where in the body is bile made?
Bile is made in the liver and stored
| in the gall bladder.
71
What is a double circulatory system?
Where blood from the heart is
| pumped to the lungs and the body at the same time.
72
What is a pacemaker?
A group of cells in the right atrium that controls
| the heart rate.
73
What is the role of the coronary arteries?
To supply oxygenated blood
| to the heart muscle.
74
Where does the left atrium pump blood to?
To the left ventricle.
75
Where does gas exchange take place in the lungs?
In the alveoli.
76
Name the gas that moves from the blood into the lungs
carbon dioxide
77
Name the blood vessels that carry blood away from the heart
Arteries.
78
Which blood vessels are only one cell thick?
capillaries
79
Which blood vessels have thick muscular walls?
arteries
80
Which blood vessels have valves?
veins
81
What is plasma?
The pale yellow fluid part of blood, it transports
cells, CO2
, hormones and waste.
82
What is the role of a red blood cell?
To carry oxygen around the
| body.
83
In what two ways can white blood cells fight infection?
They can
produce antibodies that destroy microbes or they can engulf
microbes.
84
What is the role of platelets?
They form clots to reduce bleeding.
85
What is coronary heart disease?
Where layers of fatty material build
| up inside the coronary arteries narrowing them.
86
What are the risk factors for coronary heart disease?
Smoking, high
| blood pressure, high cholesterol and not enough exercise.
87
What is a stent?
A metal cylinder grid that is inserted into an artery
| to keep the artery open.
88
What are statins?
Drugs that reduce the harmful cholesterol in the
| blood
89
What is the role of heart valves?
To stop the blood in the heart from
| flowing in the wrong direction.
90
Give two faults that can occur with heart valves.
They may not open
| fully or develop a leak.
91
What treatment can be given to a person with faulty heart valves?
They can have their heart valves replaced (biological or mechanical).
92
Name three conditions that can lead to heart failure.
Atherosclerosis
| CHD), cardiomyopathy, congenital heart disease (born with it
93
Define the word health.
A state of complete physical and mental well-being
| and not merely the absence of disease or infirmity.
94
What are communicable diseases?
Infectious diseases caused by microbes
| that can be spread.
95
What are non-communicable diseases?
Diseases not caused by infections and
| cannot be spread.
96
Name 4 ways that different types of disease can interact to make a person ill.
Defects in the immune system, viruses that can trigger cancer, immune
reactions caused by pathogens, physical ill health.
97
List some human costs of non-communicable diseases
Lower quality of life,
| shorter life span.
98
List some financial costs of non-communicable diseases
Healthcare costs,
| reduced income, buying of specialist equipment.
99
Name two other risk factors that affect health
Lifestyle and substances taken
| into the body or in the environment.
100
What are the risk factors for cardio vascular disease?
Diet, smoking, lack of
| exercise.
101
How does alcohol cause liver disease?
It causes the liver to
| become fatty and this can lead to cirrhosis.
102
What does alcohol damage in the brain?
It damages the nerve
| cells and the brain mass may shrink.
103
What is COPD?
A group of lung diseases that narrow airways
| making it difficult for people to move air in and out of the lungs.
104
What is a carcinogen?
A substance that can cause cancer.
105
How can carcinogens cause cancer?
They damage DNA or speed
| up cell division and increase the chance of a mutation occurring.
106
Name four types of carcinogens?
Tobacco, alcohol, occupational
| carcinogens, ionising radiation.
107
What is a tumour?
A mass of cells caused by uncontrolled cell
| growth.
108
What are benign tumours?
An abnormal growth of cell in a
| membrane contained in one area.
109
What are malignant tumours?
Cancerous.
An abnormal growth of cells that
invade other tissues and can spread in the body.
110
What is a plant tissue?
A group of similar plant cells working
| together to carry out a particular function.
111
Epidermal
Epidermal
| Covers the surfaces of the plant for protection
112
Palisade mesophyll
The cells are packed with chloroplasts it is the site of most of
the photosynthesis
113
spongy mesophyll
Photosynthesis also occurs in the cells here. Large air spaces
for gas exchange
114
xylem and phloem
Form vascular bundles and transport water, mineral ions and
glucose around the plant
115
meristem
Found at the tips of roots and shoots. Where cell
differentiation occurs
116
what is the role of the leaf organ
Photosynthesis and respiration.
117
What is the role of the guard cells?
To open and close to let gases
| diffuse in and out through the stoma.
118
What is a plant organ?
A group of plant tissues working together to
| carry out a particular function.
119
Name the organs in the plant organ system that transports
| substances around the plant.
Stem, leaf and root.
120
What is the role of the root hair cell?
To take in water and mineral
| ions from the soil.
121
What is transpiration?
The movement of water and mineral ions
| from the roots to the stems and leaves.
122
What is translocation?
The movement of dissolved sugars from the
| leaves to the rest of the plant for immediate use or storage.
123
What factors increase the rate of transpiration?
Increased
| temperature, humidity, air movement and light intensity.
124
B1: Where is the genetic material in a prokaryotic cell?
In a bacterial DNA loop and there may be one or more plasmid rings.
125
Where is the genetic material in a eukaryotic cell?
The DNA is in chromosomes enclosed in a nucleus.
126
Units
milli (mm) - 0.001m
micro - 0.000 001m
Nano (nm) -0.000 000 001m
127
Sperm
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
nerve cell
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
muscle cell
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
Root hair cell
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
xylem cell
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
phloem cell
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
What does cell differentiation mean?
When a cell changes to become specialised.
134
In what stage of an animal’s life cycle do most cells differentiate?
In the early stages.
135
In mature animals when do cells still need to differentiate?
For repair and replacement of cells.`
136
In what stage of their life cycle do plant cells differentiate?
They differentiate throughout their lifecycle.
137
Define the term resolution.
The shortest distance between two objects that can be seen clearly.
138
What are the advantages of the electron microscope?
Electron microscopes
have a higher magnification and resolution than light microscopes; scientists
can see more sub-cellular structures.
139
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.
M = I/A M = 375/2.5 = 150 M = 150 times
140
Describe how you would make an onion cell slide.
• 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
Describe how you would use the light microscope to view onion
cells.
• 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
What is ‘binary fission’?
Cell division where two identical cells to the
| parent cell are formed.
143
Why do you need to sterilise Petri dished and culture mediums before
use?
To kill any unwanted microorganisms.
144
What would you use an inoculating loop for?
To transfer bacteria onto
| the agar.`
145
How do you sterilise an inoculating loop?
By heating in a Bunsen flame.
146
How would you secure the lid of the Petri dish?
With tape but not sealed
| all the way around.
147
What temperature would you incubate the samples at in a school and
why should you use this temperature?
25oC, to prevent the growth of
| pathogens harmful to humans.
148
How can you test the effectiveness of antibiotics and disinfectants on
bacteria?
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
What are chromosomes?
Coiled strands of DNA molecules.
150
What is a gene?
A section of DNA that codes for a protein.
151
What is DNA?
A genetic material found in the nucleus that codes for proteins.
152
Where in a cell do you find chromosomes?
In the nucleus of cells.
153
How many chromosome pairs do you find in a human body cell?
23 pairs
154
What are the three stages of the cell cycle?
Growth, DNA synthesis
| and mitosis.
155
What is mitosis and what is it used for in animals and plants?
Growth, repair and asexual reproduction.
156
What is a stem cell?
An undifferentiated cell.
157
Which type of human stem cell can differentiate into any human
cell?
Embryo stem cells.
158
What is therapeutic cloning?
Where patients are given stem cells
| containing the same genes as theirs.
159
What are the risks of therapeutic cloning?
Viral infections.
160
State two reasons why people may object to the use of stem cells
in therapeutic cloning.
Ethical and religious reasons.
161
What are meristems?
Structures in plants that contain stem cells.
162
State two reasons that plants are cloned?
To clone rare species of
| plants and to clone crop plants with useful characteristics.
163
Define ‘diffusion’?
The spreading of the particles from a region where they are of a
higher concentration to an area of lower concentration.
164
State three places where diffusion occurs in the body.
Small
| intestines, lungs, kidneys
165
What is a concentration gradient?
The difference in concentration
| between two areas next to each other.
166
What three factors affect rate of diffusion?
Concentration gradient,
| temperature, surface area.
167
What is surface area to volume ratio?
The size of a surface
| compared to its volume.
168
Diffusion: The small intestines.
Have villi to increase surface area, good
| blood supply, thin membranes.
169
diffusion: the lungs
Have alveoli to increase surface area, good blood
| supply, thin membranes, they are ventilated.
170
diffusion: gills in fish
Have gill filaments and lamella to increase surface
| area, good blood supply, thin membranes.
171
diffusion: roots
Have root hair cells to increase surface area.
172
diffusion: leaves
Large surface area, thin and stomata.
173
Define osmosis?
Osmosis is the diffusion of water from a dilute
solution to a concentrated solution through a partially permeable
membrane.
174
What is a partially permeable membrane?
A membrane that lets
| some but not all substances through.
175
What happens to an animal cell in a hypertonic solution?
It will
| lose water by osmosis and shrivel.
176
What happens to an animal cell in a hypotonic solution?
It will
| absorb water by osmosis and get bigger/burst.
177
Define active transport.
Active transport moves substances from a
more dilute solution to a more concentrated solution (against a
concentration gradient) using energy from respiration.
178
Why does active transport need to occur in root hair cells?
Because the minerals are at a higher concentration in the roots than in
the soil.
179
Why does active transport need to occur in the gut?
Because the
| glucose in the blood is at a higher concentration than in the gut.
