Download B2 revision questions

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Topic 1 – Building Blocks of Cells
What is the function of the flagella of a bacteria
cell?
What is the function of the cell wall of a
bacteria cell?
What is the function of the chromosomal DNA
in a bacteria cell?
What is the function of the plasmid DNA in a
bacteria cell?
What is the function of a plant cell wall?
Answers
For movement
For support and to keep the cell’s shape
Carry most of the genetic material for the
bacteria
To carry small amounts of extra genetic
material
For support and to keep the shape of the cell
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What is the function of chloroplasts?
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What is the function of the vacuole?
Contain chlorophyll which absorb light for
photosynthesis
Contains sap and helps keep the cell rigid
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What is the function of the cell membrane?
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What is the function of the cytoplasm?
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What is the function of the nucleus?
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What is the function of mitochondria?
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What piece of equipment lets us see cells in
more detail?
How can you calculate the magnification of a
microscope?
How can you calculate the actual length of a
specimen under a microscope?
What is a gene?
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Describe a DNA molecule
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How do the base pairs in DNA pair up?
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Who were the scientists involved in the
discovery of DNA?
What is the significance of the human
genome project?
How does genetic engineering work?
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What are some uses of genetic engineering?
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Controls the movement of substances in and out
of the cell
Where chemical reactions take place and
contains organelles
Contains the DNA and controls the cell’s
activity
They are where respiration takes place for
energy
A microscope
Objective lens magnification X eyepiece lens
magnification
Length of the magnified object/magnification
A section of DNA that codes for a specific
protein
Two stands in a double helix linked by base
pairs in hydrogen bonds
Adenine (A) with Thymine (T)
Cytosine (C) with Guanine (G)
Franklin, Wilkins, Watson and Crick
It was a collaboration between many
scientists around the world which lead to a
better understanding of human biology and
many possible medical advances
A gene from one organism is extracted and
placed into the DNA of another organism
Beta carotene in rice used to treat vitamin A
deficiency
Production of human insulin by GM bacteria
Herbicide resistant crops
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What are some disadvantages of genetic
engineering
What is a diploid cell?
Seen as dangerous by some
Unknown consequences in GM organisms get
into the wild
A cell dividing to produce two genetically
identical, diploid, daughter cells
A cell dividing to produce four, genetically
unique, haploid, daughter cells
A cell with two copies of each chromosome
What is a haploid cell?
A cell with only one copy of each chromosome
When does mitosis happen?
During growth, repair or asexual reproduction
What happens during fertilization in sexual
reproduction?
What is cloning
Two haploid cells combine to make one diploid
cell
A type of asexual reproduction that produces
genetically identical copies
1. Removal of a diploid nucleus from a
body cell
2. Enucleating (removing the nucleus)
an egg
3. Insertion of diploid nucleus into
enucleated egg
4. Stimulation of diploid nucleus to
divide by mitosis
5. Implantation into surrogate mammal
Replicating individuals with desirable
characteristics
It is very difficult to do, so uses many egg cells
What is mitosis?
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What is meiosis?
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What are the stages in cloning a mammal
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What are some advantages of cloning?
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What are some drawbacks of cloning?
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What are some risks of cloning?
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What is a stem cell?
Possible medical problems with cloned animals,
such as premature aging.
A cell that can differentiate into any type of cell
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What are the advantages of stem cell research?
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What are disadvantages of stem cell research?
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What are the risks of stem cell research?
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What decides the type and order of amino acids
in a protein made in a cell?
More reliable treatments for diseases such as
leukaemia
The ability to produce matching organs for
people in need of donor organs
It could be used to clone humans illegally
Involves destroying human embryos, which
some people see as murder.
Stem cells could develop into the wrong type of
cell or even cancer.
The order of the bases in DNA
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Describe how protein synthesis works?
Transcription:
Production of a complimentary strand
of mRNA in the nucleus
Translation:
• Attachment of mRNA to a ribosome
• Coding by triplets of bases (codons) in
the mRNA for specific amino acids
• Amino acids transported to the
ribosome by tRNA amino acids linked
to form a polypeptide chain
A polypeptide chain with a specific number and
order of amino acids and a specific shape which
have different functions such as enzymes
A change in the order of DNA bases which
causes a change in the amino acid order in a
polypeptide and therefore a change in the
structure of the final protein produced.
They can be harmful, beneficial or neither.
Biological catalysts
DNA replication
Protein synthesis
Digestion
Temperature
pH
Concentration
Enzymes are a specific shape to fit their
substrate
An enzyme that doesn’t work because the shape
of the active site has changed its shape
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Describe a protein
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What is a gene mutation?
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What is an enzyme?
Give some examples of reactions that enzymes
catalyse
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What factors affect enzyme action?
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What is the ‘lock and key’ hypothesis of how
enzymes work
Define a denatured enzyme
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Topic 2 – Organisms and Energy
What is respiration?
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In what two ways does the human circulatory
system facilitate respiration?
Define diffusion
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Describe aerobic respiration
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Give a word equation for aerobic respiration
The process by which all living organisms
release energy from organic molecules
1. Glucose and oxygen diffuse from
capillaries into respiring cells
2. Carbon dioxide diffuses from respiring
cells into capillaries
The movement of particles from an area of high
concentration to an area of low concentration
The use of oxygen to release energy from
glucose, producing water and carbon dioxide as
by-products
Oxygen+glucoseàcarbon dioxide+water
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Why do heart rate and breathing rate increase
during exercise?
Exercising muscles are doing more aerobic
respiration to produce energy, so need more
oxygen and glucose. Waste carbon dioxide can
also be removed quicker.
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How can you calculate cardiac output?
What is cardiac output?
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What is stroke volume?
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What is heart rate?
What is anaerobic respiration?
Why do cells have to respire anaerobically
sometimes during vigorous exercise
What is the word equation for anaerobic
respiration?
What produces more energy, aerobic or
anaerobic respiration?
How is lactic acid broken down and removed
from the body?
What is EPOC
What do heart rate and breathing rate remain
high after exercise has finished?
How is a leaf adapted for photosynthesis?
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What is the word equation for photosynthesis?
What provides the energy for photosynthesis?
What is a limiting factor?
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Give three examples of limiting factors
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What is transpiration and what drives it
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How is water taken into the roots of a plant?
How are minerals taken into the roots of a
plant?
What do xylem vessels transport?
What do phloem vessels transport
Define osmosis
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How is a root hair cell adapted for absorbing
water
What equipment can be used to sample the
distribution of organisms in an ecosystem?
What factors can affect the distribution of
organisms in an ecosystem?
Stroke volume X heart rate
The volume of blood leaving the heart every
minute
The volume of blood leaving the heart every
beat
The number of times the heart beats per minute
Respiration without oxygen
The cells cannot get enough oxygen to meet the
energy demand through aerobic respiration
Glucose à Lactic acid
Aerobic respiration
It reacts with oxygen to form carbon dioxide
and water, which are removed in the blood
Excessive post exercise oxygen consumption
Your cells still need oxygen to break down the
lactic acid built up during exercise
Large surface area
Lots of chlorophyll
Stomata for gas exchange
Carbon dioxide+wateràoxygen+glucose
Light
Something that can limit the maximum rate of
photosynthesis due to its lack of availability
Light intensity
Carbon dioxide concentration
Temperature
The movement of water through a plant, driven
by the evaporation of water from the leaves
Osmosis
Active transport (requiring energy)
Water and minerals
Glucose
The movement of water from an area of high
concentration to an area of low concentration
through a semi-permeable membrane
Large surface area
No Chloroplasts
• Pooters
• Sweep nets/pond nets
• Pitfall traps
• Quadrats
• Light intensity
• Temperature
• pH
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Topic 3 – Common Systems
How do fossils give evidence for evolution?
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Why are there some gaps in the fossil record?
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How do pentadactyl limbs provide evidence
for evolution?
What is ‘growth’
What causes plants to grow?
What causes growth in animals?
What is the structure and function of a red blood
cell?
What is the structure and function of white
blood cells?
What is the structure and function of platelets?
What is the structure and function of blood
plasma
What is a tissue?
What is an organ?
What is an organ system?
What are the four major blood vessels of the
heart?
Where does the aorta go from and to?
Where does the vena cava go from and to?
Where does the pulmonary artery go from and
to?
Where does the pulmonary vein go from and to?
Which side of the heart pumps oxygenated
blood?
Which side of the heart pumps deoxygenated
blood
What is the job of the heart valves
Which ventricle has a thicker wall and why?
What direction to arteries carry blood
What direction do veins carry blood?
Where do capillaries carry blood and why?
What is the function of the mouth in digestion?
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They show the gradual change in living things
over time
Conditions do not always allow fossils to form
Soft tissue does not easily form a fossil (it
decays)
Many fossils are yet to be found
The similar structure suggests that the all
evolved from one common ancestor
An increase in mass, length or size
Cell division, elongation and differentiation
Cell division and differentiation
A small cell in a ‘squashed disc’ shape with no
nucleus to give it more space to carry oxygen on
the haemoglobin it contains
Large cells that fight infection by either
engulfing pathogens or producing
antibodies/antitoxins
Fragments of cells that form clots when the skin
is cut
The liquid part of blood, carries other dissolved
chemicals such as glucose and carbon dioxide
A group of cells working together
A group of tissues working together
A group of organs working together
Aorta, vena cava, pulmonary artery, pulmonary
vein
From the left ventricle to the body
From the body to the right atrium
From the right ventricle to the lungs
From the lungs to the left atrium
Left
Right
To prevent blood flowing in the wrong direction
(backflow)
The left, because it has to pump blood at higher
pressure
Away from the heart
Towards the heart
Through tissues, to exchange materials such as
oxygen and carbon dioxide
Mechanically break up food into a bolus,
produce saliva to start digestion with enzymes
and lubricate food
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What is the function of the oesophagus in
digestion?
What is the function of the stomach in
digestion?
What is the function of the small intestine in
digestion?
What is the function of the large intestine in
digestion?
What is the function of the pancreas in
digestion?
What is the function of the liver in digestion?
What is the function of the gall bladder in
digestion?
What is the alimentary canal?
What is peristalsis
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What enzymes break down carbohydrates and
give an example
What enzymes break down proteins and give
two examples
What enzymes break down fats?
What do carbohydrates get broken down into?
What do proteins get broken down into?
What do fats get broken down into?
What are the roles of bile?
How do villi aid digestion?
Which functional foods claim to improve
health?
How do Probiotics claim to improve health?
How do Prebiotics claim to improve health?
How do plant stanol esters claim to improve
health?
To transport the bolus to the stomach
Acid kills bacteria on food and allows enzymes
to work better, food is churned up
Use enzymes to break down food molecules and
absorb them into the blood
Absorbing water
Production of enzymes
Production of bile
Storage of bile
The tube through the body from mouth to anus
where digestion happens
When the muscular wall of the alimentary canal
squeezes and pushes food through it to help
digestion
Carbohydrases – amylase
Proteases – pepsin and trypsin
Lipases
Simple sugars
Amino acids
Fatty acids and glycerol
To emulsify fats and neutralize stomach acid
They increase surface area in the gut and
make absorption of nutrients more efficient
Probiotics – Lactobacillus and bifidobacteria
Prebiotics – oligosaccharides
Plant stanol esters
By adding to the bacteria in the gut
By providing food for the bacteria in the gut
By lowering cholesterol