Practice Questions Flashcards
1
Q
Describe homeostasis
A
The regulation of internal conditions of a cell or organism to maintain optimum conditions for function, in response to internal and external changes
2
Q
During exercise, what causes the skin to appear red?
A
Vasodilation of blood vessels
3
Q
How does the thermoregulatory centre send information to sweat glands in the skin?
A
Via nerve impulses
4
Q
Explain why the temperature near the brain decreased after drinking cold water
A
Blood is cooled at the stomach and then flows to the brain
5
Q
Describe the advantages and disadvantages of having a kidney transplant instead of having dialysis
A
Advantages:
- no need for regular hospital visits
- flexible lifestyle, no need to control diet
- cheaper long term for the NHS
Disadvantages:
- risk of rejection
- need to take immunosuppressant drugs
- risk from surgery and long recovery time
6
Q
Which organ produces urine?
A
Kidney
7
Q
Name the process by which water is lost from the skin
A
Sweating
8
Q
Why does the body need to lose water from the skin?
A
- For cooling
- To maintain body temperature
9
Q
Describe how the body responds when a decrease in core body temperature is detected
A
- Vasoconstriction of blood vessels
- Less blood flow so less energy is lost to the surroundings
- Less sweating occurs
- Shivering by muscle contraction
- Respiring more
10
Q
How does the lens refract light more?
A
By becoming thicker
11
Q
Which two structures control the shape of the lens?
A
Ciliary muscles and suspensory ligaments
12
Q
What is meant by the term ‘reflex action’?
A
An automatic response
13
Q
Give three ways coordination by the endocrine system is different from coordination by the nervous system
A
Co-ordination by the endocrine system is:
- slower
- longer lasting
- via chemical hormones in the blood instead of neurones
14
Q
Describe how hormones control the menstrual cycle
A
- FSH stimulates the maturation of an egg
- Oestrogen inhibits the release of FSH and stimulates the LH production
- LH stimulates ovulation
- Progesterone inhibits both LH and FSH production
- Oestrogen and progesterone maintain the uterus lining
15
Q
Which part of the brain controls balance when riding a bicycle?
A
Cerebellum
16
Q
What type of cell carries impulses from the ears to the brain?
A
Neurone
17
Q
Describe how the brain receives information about light entering the eye
A
- Retina cells sensitive to light
- Impulse passes along sensory neurones
- Along optic nerve
18
Q
What is a hormone? (3 marks)
A
- a chemical messenger, made by the endocrine system
- it is secreted by a gland and transmitted in the bloodstream
- where it travels to the target organ
19
Q
Suggest why a blood test is more reliable than a urine test
A
There is not a lot of glucose in urine compared to the blood
20
Q
Name the structures inside the cell nucleus that contain DNA
A
chromosomes
21
Q
What type of substance does a gene code for?
A
Protein
22
Q
What is the name of the type of cell division that produces sperm cells?
A
Meiosis
23
Q
How could the student keep the milk at a constant temperature for 5 days?
A
Place the beaker in a water bath
24
Q
What is meant by the term ‘reflex action’?
A
An automatic response
25
Describe how algae get energy
- From light
- Absorbed by chlorophyll
26
Name two types of microorganisms that cause decay
- Bacteria
- Fungi
27
Name the product that causes the pH to decrease
Fatty acids
28
Give one way the pH can be measured
- Using a pH probe
- Universal indicator
29
Describe how fishing quotas can help to return fish stocks to a sustainable level
- Fewer fish are caught
- So more remaining fish that can reproduce
30
Describe why more land is being used for farming and how increased farming has decreased biodiversity
- Increasing population requires more food, so more crops and livestock are grown for food
- Farming crops are also grown to be used as biofuels
- To create more land for farming, deforestation levels have increased which destroys habitats for animals, decreasing biodiversity
31
What are three uses of gibberellins?
- To start germination
- To increase fruit size
- To promote flower production
32
Why does storing bananas with other fruits cause the other fruits to ripen faster?
Ethene is released from the bananas
33
Why is DNA described as a polymer?
It is made up of many joined nucleotides
34
Describe the structure of a nucleotide
- Made up of a phosphate
- Which is attached to a sugar
- The sugar is attached to one of four bases
- The bases are A, C, T, G
35
Describe how non-coding parts of DNA can affect the expression of genes
The non-coding parts can switch genes on or off
36
Describe four differences between the processes of mitosis and meiosis
- Mitosis produces two daughter cells whilst meiosis produces four daughter cells
- Cells made from mitosis have 46 chromosomes whilst cells made from meiosis have 23 chromosomes
- During mitosis there is only one cell division but during meiosis there are two cell divisions
- Mitosis produces genetically identical cells, but meiosis produced genetically different cells
37
Describe two similarities between the processes of mitosis and meiosis
- DNA doubles
- Increase in the number of sub-cellular structures
38
Name the part of the brain that is responsible for making a decision
Cerebral cortex
39
Suggest how the fMRI scanner could help to find out more about the brain damage a person has
- Can ask people to do different tasks (while taking scan)
- To see which part of brain is active / inactive
- To compare with a person without brain damage
- To see (exactly) where the damage is
- (Traditional) MRI scanner cannot be used if people can’t stay still
40
Describe two reasons why the biomass of the insects eaten by dogs does not all become biomass of the dogs
- Not all parts of the insect are digested by the dog
- Some of the biomass that the dog takes in is lost as waste, urea from excretion (faeces)
41
Explain how making dog food from insects could improve human food security in the future
- Less land is required
- So there is more room for crops for humans
- Less methane released from animals and rotting vegetables in landfills
- Therefore less harmful effects of global warming on food production
42
Give three reasons why the fossil record is not clear for older species
- Fossils buried deeper so they are harder to find
- More likely to be destroyed by geological activity e.g. earthquake
- Dating older fossils is hard
43
Give one disadvantage and one advantage of mass extinction events
Advantage: allows the evolution of new species
Disadvantage: loss of potential, future biodiversity
44
Explain how the person’s eye could adjust to form a clear image of a nearer object
- Ciliary muscles contract so they have a smaller diameter
- Suspensory ligaments loosen
- Lens is more rounded and thick
- Lens is more convergent
- Light rays are focused onto the retina
45
Describe how spectacle lenses can correct long-sightedness
- Convex lens
- Light rays refracted more
- Light rays focused onto the retina
46
What changes the size of the pupil?
The iris
47
explain how the person's eye could adjust to form a clear image of a nearer object (6 marks)
- ciliary muscles contract
- so they have a smaller diameter
- suspensory ligaments loosen
- lens more rounded
- lens is more convergent
- refracts light more
- light rays are focussed onto the retina
48
what are the advantages of sexual reproduction?
- increases genetic variation
- diseases are less likely to affect population (due to variation)
- the species can adapt to new environments due to variation, giving them a survival advantage
49
what are the disadvantages of sexual reproduction?
- takes time and energy to find mates
- difficult for isolated members of the species to reproduce
50
what are the advantages of asexual reproduction?
- more time and energy efficient
- reproduction is completed much faster than sexual reproduction
- population can be increased rapidly when conditions are right
- can exploit suitable environments quickly
51
what are the disadvantages of asexual reproduction?
- limited genetic variation in population, offspring are genetically identical to parent
- population is vulnerable to changes in environmental conditions
- disease is likely to affect the whole population as there is no genetic variation
52
what is meant by 'extinct'?
none of the species left/died out
53
give one way in which an increase in household waste affects our environment
- increased pollution
- increased landfill/dumping waste
54
give one problem caused when sulfur dioxide gas is in the air
- acid rain
- erosion of statues
- destruction of habitats
- reduction in biodiversity
- breathing problems
55
give two effects of global warming on the environment
- glaciers melting
- sea levels rising
- flooding and droughts
- habitat destruction
- changes to migration patterns
- extinction
56
give two reasons why farmers are in favour of growing GM crops
- higher yield
- less use of pesticide
57
explain why the gardener may be against producing compost using anaerobic decay
- methane is released
- which is a greenhouse gas and contributes to global warming
58
Some of the leaves from the gardener’s strawberry plant die. The dead leaves fall off the strawberry plant onto the ground. The carbon in the dead leaves is recycled through the carbon cycle. Explain how the carbon is recycled into the growth of new leaves.
- the carbon in the dead leaves is broken down by microorganisms
- the organisms respire and release the carbon from the leaves as carbon dioxide
- plants use the carbon dioxide released in photosynthesis
- the carbon dioxide is used to produce glucose
- plants use glucose to make amino acids
- which are required for the growth of new leaves
59
Give three possible reasons that may have caused strawberry A to decay.
- higher temperature
- more oxygen
- more water
- contained more microorganisms that cause decay
60
explain how the amount of sunlight could affect the distribution of the buttercup plants
- light is needed for photosynthesis
- for making food for growth
- more buttercups in sunny areas
61
when fertiliser goes into the river, the concentration of oxygen dissolved in the water decreases, explain why the concentration of oxygen decreases
- fertiliser causes growth of algae
- algae blocks light
- low light causes plants to die
- microorganisms cause decay of dead plants
- aerobic respiration uses oxygen
62
give two reasons why the mass of household waste is increasing each year
- rapid growth in population
- increase in standard of living
63
what effect does the destruction of peat bogs have on the gases in the atmosphere?
increases carbon dioxide in the atmosphere
64
describe one effect of deforestation on ecosystems
- reduced biodiversity
- destruction of habitats
- disruption of food chains
65
give two reasons why forests in tropical areas are being cut down at a high rate
- agriculture
- buildings
- timber
66
explain how this deforestation is affecting the composition of gases in the atmosphere
- deforestation increases carbon dioxide levels in the atmosphere
- less trees means reduced photosynthesis
- less carbon dioxide absorbed by the trees
- when the trees are burnt the locked-up carbon in the wood is released as carbon dioxide
- when decomposers break down these dead pieces of plant
- they respire and release carbon dioxide
67
explain why rain forests are being burnt to provide land for crops in many parts of the world
- increased human population
- increased standard of living
68
explain why such cleared land will often produce crops for only a few years
nutrients absorbed by plants are not replaced
69
explain the effects that large-scale burning of forests may have on the Earth's atmosphere in the short and in the long term
- increased release of carbon dioxide into atmosphere
- when trees are burned reduced rate of carbon dioxide removal from atmosphere
- increased carbon dioxide absorbs more of energy radiated by Earth
- global rise in temperature
70
suggest one way a grower could increase the yield of tomatoes from plants growing in his greenhouse
- increase temperature
- increase light
- increase carbon dioxide concentration
- add fertiliser/nutrients
71
suggest two reasons why a supermarket might decide to import tomatoes rather than buy them from British growers
- cheaper
- better quality
- available all year
72
importing tomatoes may be more damaging to the environment than selling tomatoes grown in this country, explain why
- greater distance to transport food
- transport needs more energy
- carbon dioxide release contributes to global warming
73
explain the effects of adding large amounts of methane to the atmosphere
- absorbs heat radiated by the earth
- some heat reradiated
- leading to global warming
74
the farmer sprayed pesticide on his potato plants, the next day it rained heavily, explain why the biodiversity in the river decreased (2 marks)
- the pesticide washed into the river
- pesticide kills some organisms in the river
75
why does sexual reproduction produce variation?
- sexual reproduction involves meiosis
- there is mixing of genetic information
- which leads to variety in the offspring
76
why does asexual reproduction produce genetically identical offspring?
- asexual reproduction only involves mitosis and one parent
- so there is no fusion of gametes and no mixing of genetic information
- this leads to genetically identical offspring
77
describe the process of meiosis
- copies of the genetic information are made
- the cell divides twice to form four gametes, each with a single set of chromosomes
- all gametes are genetically different from each other
78
give one artificial use of a steroid hormone in the body
- stimulate muscle growth
- used in oral contraceptives
79
suggest how statins work (1 mark)
reduces production of cholesterol
80
describe the process of protein synthesis
- genes in the DNA are copied onto a template
- template leaves nucleus
- proteins are synthesised on ribosomes
- carrier molecules in cytoplasm bring specific amino acids to ribosome
- and bind them to form amino acid chain
- template determines the order of the amino acids in the chain
- when the amino acid chain is complete, it folds up in a unique shape to form specific protein
81
name the three different types of neurones
- sensory
- relay
- motor
82
explain the changes that occur in the normal human eye to focus on near and distant objects
near objects:
- ciliary muscles contract
- suspensory ligaments loosen
- lens is more rounded
- light is refracted strongly
distant objects:
- ciliary muscles relax
- suspensory ligaments tighten
- lens is thinner
- light is only refracted slightly
83
explain how long-sighted people are unable to focus on near objects and how this can be corrected using glasses
- eyeball is too short
- light is refracted behind the retina
- can be corrected using glasses with a convex lens
- so that light is focussed onto the retina
84
explain how laser eye surgery can correct a person's eyesight and suggest a reason why it is not as popular as other methods of vision correction
- laser eye surgery can be used to precisely remove cells of the cornea
- changes the shape of the cornea
- which affects how strongly it refracts light
- requires surgical procedure so there is a risk of complications
- and it is very expensive compared to other methods
85
explain how laser eye surgery can correct myopia
- lasers are used to treat myopia by reducing the thickness of the cornea
- so it refracts light less strongly
- lens now focuses distant light on the retina instead of in front of the retina
86
explain how laser eye surgery can correct hyperopia
- lasers are used to change the curve of the cornea
- refracts light more strongly
- so it refracts light from close objects more effectively
- lens now focuses near light on the retina instead of behind of the retina
87
what are some problems with IVF?
- it is very emotionally and physically stressful
- the success rates are not high
- it can lead to multiple births which are a risk to both the babies and the mother
88
what is variation?
the differences in the characteristics of individuals in a population
89
describe the process of adult cell cloning
- the nucleus is removed from an unfertilised egg
- the nucleus is taken from an adult body cell
- the nucleus from the adult cell is inserted into the empty egg cell
- an electric shock stimulates the egg cell to start dividing to form embryo cells
- these cells contain the same genetic information as the original adult
- when the embryo is developed into a ball of cells, it is inserted into the uterus of an adult female to continue its development
