Biology GCSE (B2) Questions
1
Question
Describe the structure of DNA
2
How do the bases pair up?
3
Genes contain the code for making
what?
Name a useful protein that can be
Insulin
produced by transferring the relevant
gene into bacteria.
What do we call it when humans
Genetic modification
transfer useful genes from one
species to another?
What is fermentation?
When microorganisms use an external
food source to obtain energy, thereby
changing some of the substances around
them e.g. glucose→ethanol
What is a fermenter?
A vessel used to cultivate
microorganisms
Name 6 conditions that have to be
• Aseptic conditions
maintained in a fermenter to
• Supply of food/nutrients
maximise growth of the
• Optimum temperature
microorganisms
• Optimum pH
• Oxygen/air supply
• Agitation/stirring
What are the advantages of using
• Rapid growth, easy to grow
microorganisms for food
• Production is independent of
production?
climate
• Waste products from industry can
be used as a food source for the
microbes
A protein is a long string of many
Amino acids
what?
Where does transcription take place? In the nucleus.
What does the ‘m’ stand for in
Messenger.
mRNA?
Where does translation take place?
In the cytoplasm. Ribosomes translate the
Name the organelle that translates
message, and they’re found in the
the mRNA message into protein
cytoplasm.
What is a triplet (or codon)?
A series of three DNA bases that code for
a particular amino acid.
Name the small RNA molecule that Transfer RNA (tRNA)
the ribosome matches to the mRNA
triplets.
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10
11
12
13
14
Answer
A double helix with the two strands
linked by a series of paired bases;
‘twisted ladder’
Adenine with Thymine, and Guanine with
Cytosine
Proteins
15 Give three differences between
DNA and RNA
16 What is the difference between
respiration and breathing?
17 Give the word equation for
respiration
18 How are gases exchanged in the
lungs?
19 How are gases exchanged in
respiring tissues?
20 What happens to the rates of
respiration and gas exchange during
exercise? Why?
21 What happens inside our bodies
during vigorous exercise?
22 What is the product of anaerobic
respiration? What can it cause?
23 What is mitosis?
24 What is meiosis?
•
RNA has ribose instead of
deoxyribose
• RNA is single stranded, DNA is
double stranded
• RNA has Uracil instead of
Thymine
Respiration is a chemical reaction that
happens in every cell. It releases energy
from glucose.
Breathing is ventilation, a mechanical
process in which the lungs inflate and
deflate.
Glucose + oxygen → carbon dioxide +
water.
Oxygen diffuses from the alveoli into the
capillaries, and carbon dioxide diffuses
from the capillaries into the alveoli
Oxygen diffuses from the capillaries into
the respiring cells, and carbon dioxide
diffuses from the respiring cells into the
capillaries
They increase because more energy is
required by the muscle cells
Oxygen cannot be delivered at a high
enough rate so the cells carry out
anaerobic respiration to get enough
energy
Lactic acid. Cramp.
Cell division for growth and repair
Cell division for making gametes (sex
cells)
25 Explain the differences between
• Mitosis results in 2 daughter cells,
mitosis and meiosis.
meiosis in 4
• Mitosis produces diploid
daughters, meiosis haploid
• Mitosis gives daughter cells that
are genetically identical to parent
cells, meiosis gives genetically
different daughter cells
26 What do haploid and diploid mean? Haploid: having half the normal number
of chromosomes
Diploid: having the full complement of
chromosomes
27 How many chromosomes do humans 46 (23 pairs)
have?
28 Give four ways we can measure the
growth of an organism
29 What is cell elongation?
30 What is differentiation?
31 Why are scientists interested in stem
cells?
21 What is the name given to the
maximum number of times a cell
can divide?
33 Which cells have no Hayflick limit?
34 Why is termination of pregnancy
generally illegal after 24 weeks?
35 Name three factors that can
influence height in humans
36 Name six factors that can affect the
growth and distribution of plants
37 How are seedless fruits produced?
38 What is regeneration?
39 What is selective breeding (artificial
selection)?
40 Why might we selectively breed
• Size
• Length/height
• Wet mass
• Dry mass
When the length of a plant cell increases
in response to a stimulus e.g. light
causing the plant to grow towards or
away from the stimulus
When cells specialise; stem cells divide to
give new cells with particular features
that allow them to perform a particular
function
They can divide to give any type of cell.
Therefore:
• They could be used to treat
illnesses like Parkinson’s and
cancer
• They could be used to produce
organs for transplant, or new
limbs or tissues to repair skin,
heart etc
• They can be used to study cell
division and differentiation
The Hayflick limit
Stem cells and cancer cells
Because after 24 weeks a significan
proportion of foetuses are viable. Thjis
means that their organs are developed
enough for them to survive outside the
womb.
Genes, hormones and nutrition
- nutrients
- light
- temperature
- carbon dioxide
- oxygen
- plant ‘hormones’
A plant hormone is sprayed onto the
unpollinated flowers. This makes them
develop into fruits even though
fertilisation hasn’t taken place.
The process by which some animals can
re-grow body parts (e.g. newts, spiders,
worms, starfish)
Where animals or plants with desirable
characteristics are chosen to breed from
- improve the quality of milk from cattle
some organisms?
41 What are the two main stages in
cloning a mammal?
42 What are the similarities and
differences between plant and
animal cells?
43 Name the green pigment found in
chloroplasts
44 What is the word equation for
photosynthesis?
45 Name some ways that humans
utilise plants.
46 Name the factors that can limit the
rate of photosynthesis
47 Name the 4 main mineral salts that
are required for healthy plant growth
48 How do plants take up minerals
from the soil?
49 Name two important elements that
are continually recycled from one
chemical compound to another by
the activity of plants, animals and
microbes.
50 What is a biosphere?
51 What is the name of the process that
occurs when sewage or fertilisers
pollute waterways, resulting in the
loss of oxygen from the water?
52 What is the largest single reason for
the current observable massive
environmental changes such as
deforestation, climate change and
pollution?
53 How can we maximise energy
- increase the number of offspring in sheep
- increase the yield from dwarf wheat and
other cereal crops
-the replacement of the nucleus in an egg cell
with a diploid nucleus from a mature cell
(nuclear transfer)
- stimulation of the diploid nucleus to divide
Similarities: both have nuclei, cytoplasm
and membranes.
Differences: only plants have vacuoles,
cell walls and chloroplasts
Chlorophyll
Carbon dioxide + water → glucose +
oxygen
• Food
• Fuel
• Shelter
• Medicine
• Clothing
• Paper
• Aesthetics
• Availability of Water
• Availability of nutrients/minerals
• Availability of carbon dioxide
• Light intensity
• Temperature
magnesium, nitrogen,
phosphorus and potassium
Active transport. This requires energy
from respiration
Carbon and Nitrogen
A self-contained structure that holds all
the plants and animals needed for a
sustainable environment
Eutrophication
Human populations are growing
unsustainably
Optimum feeding/growing conditions.
transfer in food production?
54 What is interdependence?
55 What is adaptation?
56 What do we call the battle between
different types of organism for a
resource?
57 What do we call it when one animal
hunts, kills and eats another animal?
58 Name three greenhouse gases
59 Name three air pollutants not
mentioned in the previous question.
60 What is a living indicator? Give an
example.
61 What is a non-living indicator? Give
an example.
62 Give three examples of extreme
environments
Disease and predator control
The mutual dependence of organisms
within an ecosystem
Changing to suit environmental
conditions
Competition
Predation
Carbon dioxide, methane, water vapour
Sulphur dioxide, nitrogen oxides, CFCs
Evidence of the effects of pollution
shown on an organism e.g. growth of
lichens (inhibited by acidic gases), rates
of skin cancer (CFCs), populations of
aquatic invertebrates (water pollution)
Evidence of the effects of pollution
shown on a non-living aspect of the
environment e.g. average global
temperature (greenhouse gases), ozone
depletion (CFCs).
• Hydrothermal (deep sea) vents
• Antarctic
• High altitudes
63 Why is it good to recycle?
It reduces the demand for resources, and
reduces the problem of waste disposal. In
some cases it can save energy.
64 Name three conservation
management techniques.
65 Why does conservation lead to
greater biodiversity?
Reforestation, coppicing and replacement
planting
It maintains a variety of habitats, and
reduces flooding and desertification. This
leads to a greater number of species
having a suitable habitat and a reduction
in the rate of extinction.