Download B2 exam: Key words to understand

B2 exam: Key words to understand
There are lots of new key terms that you need to make sure you understand in preparation for your exam. It’s really
important that you recognise what each of the words mean and are able to use them correctly in a sentence. This
will help you to explain ideas scientifically and ensure you pick up important marks in your exam.
Some tips for learning science vocabulary.
Tip 1 -Play some games with the keywords
You could play hangman with your friends or family using the words you need to learn. Make sure you explain what
the word means when they have guessed it.
You could play Pictionary for some of the energy types or renewable energy sources. Ask someone to draw you a
picture for one of these terms and see if you can guess which one they are drawing.
Tip 2 – Use flash cards
Write out the key word and the definition on separate cards, mix them up and see if you can match the keyword
with the correct description.
Write the keyword on one side and the definition on the other. Look at the keyword side and see if you can
remember the definition or read the definition and try to remember the keyword. Turn the card over to check, or
ask someone else to read them out to you.
See if you can sort the keywords into groups of similar words. For example, you could group together all the words
that give a different type of energy. Try to explain why you have grouped them together to a friend or family
member.
Tip 3 – Spelling strategies
Use the spelling strategies that you talk about in tutor time to help with any words that you find difficult to spell.
Break it into sounds
Break it into syllables
Break it into word parts
Use a mnemonic
Refer to word in the same family
Say it as it sounds
Words within words
Make connections between words
Think about the meaning of words
Apply spelling rules
Learn by sight
(d-i-a-r-y)
(re-mem-ber, con-tin-ent)
(dis+satisfy)
(necessary—one collar, two sleeves, rhythm has your
two hips moving)
(muscle—muscular)
(Wed-nes-day)
(Parliament—I AM parliament, GUM in argument)
(bright, light, night, etc)
(bi+cycle = two+wheels)
(writing, written)
(look—cover—write—check)
B2 Topic 1: The building blocks of cells keywords lesson by lesson
Lesson
B2 Topic 1: The building
blocks of cells
B2.1 Plant and animal cells
Keyword
Meaning
Light microscope
Instrument which magnifies specimens using light and
lenses.
Surrounds plant and bacterial cells. Supports the cell
giving it strength and also help keep its shape
Thin layer which forms a semi-permeable barrier around
the cytoplasm. Controls the substances that move into
and out of the cell.
Controls the cell. Contains the DNA.
The liquid gel where most chemical reactions take place.
A space in the cytoplasm filled with cell-sap, a store of
water and nutrients. Helps support plants by keeping
them rigid.
The different structures found within cells, eg nucleus,
chloroplasts etc
Stands for deoxyribonucleic acid. Chemical that makes
up genes and chromosomes.
Where respiration occurs. Glucose is broken down using
oxygen to release energy, needed for the reactions in
the cell.
Organelle in plant that contains chlorophyll, and is where
photosynthesis.
Green pigment in chloroplasts that absorbs light energy
from the sun.
The substance that plant cell walls are made from.
The basic units of life in which many chemical reactions
needed for survival take place (eg growth)
Instrument which magnifies specimens using a beam of
electrons.
Giant loop of DNA containing most of the genetic
material.
A circle of extra DNA found only in bacterial cells.
Single celled prokaryotes with no distinct nucleus.
Long, whip-like structures (similar to a sperm’s tail) that
can be used for movement.
Thread-like structures made of DNA, found in the cell
nucleus which is divided into many genes.
A strand of DNA that codes for a specific protein that
may form one of your features (eg hair colour)
See above
The spiral structure of DNA. Two strands joined by bases.
Chemicals that link together the two strands of a DNA
molecule.
One of the bases in DNA, only pairs up with thymine.
One of the bases in DNA, only pairs up with adenine.
One of the bases in DNA, only pairs up with guanine.
One of the bases in DNA, only pairs up with cytosine.
Base pairs are joined together by weak hydrogen bonds.
The bases always pair up in the same way because of
the matching shape of the molecules.
Insoluble solid formed and separates out of the mixture.
Cell wall
Cell membrane
Nucleus
Cytoplasm
Vacuole
Organelles
DNA
Mitochondria
Chloroplasts
Chlorophyll
Cellulose
Cells
B2.2 Inside bacteria
Electron microscope
Chromosomal DNA
Plasmid DNA
Bacteria
Flagellum
B2.3 DNA
Chromosomes
Genes
DNA
Double helix
Bases
B2.4 Extracting DNA PCA
Adenine
Thymine
Cytosine
Guanine
Hydrogen bonds
Complimentary base
pairs
Precipitate
B2.5 DNA discovery
Human Genome Project
(HGP)
Genome
B2.6 Genetic engineering
Genetic engineering
Genetically modified
organisms (GMOs)
Insulin
Cutting enzyme
Sticking enzyme
Beta-carotene
Herbicide
Biodiversity
Herbicide resistant
Golden rice
B2.7 Mitosis and meiosis
Mitosis
Meiosis
Haploid
Diploid
Growth
DNA replication
Daughter cells
Parent cell
Sexual reproduction
Asexual reproduction
Gametes
Fertilisation
Zygote
Embryo
Alleles
B2.8 Clones
Clone
Enucleated
Implanted
Uterus
A project to order all of the base pairs of the human
genome involving many scientists from different
countries working together.
All of the genetic information (DNA) of an organism, as a
list in order of every base.
The process of removing a gene from one organism and
inserting it into the DNA in a cell from another organism.
An organism that has had a gene from another species
inserted into its own DNA.
The hormone which decreases blood glucose
concentration. Used in the treatment of type I diabetes.
Cutting or restriction enzymes are enzymes that cut a
DNA molecule at a particular place.
Enzymes used to insert a gene that has been taken from
another organism and is to be incorporated into the DNA
of another organism.
Substance in the human diet from which the body makes
vitamin A.
Chemical that kills plants , usually used on weeds.
The variety of species present within a given area.
A plant that has evolved so that it is not affected by the
chemicals (herbicides) usually used to kill it.
Genetically engineered rice which produces betacarotene in the rice grains turning them yellow.
Where a parent cell divides to produce two genetically
identical diploid cells.
Where a parent cell divides to produce 4 genetically
different haploid cells.
Containing a single set of chromosomes, as in gametes.
A cell that has two sets of chromosomes. In humans
almost all cells are diploid except for egg and sperm.
Increase in size, length and mass, as well as increase in
cell number.
When the chromosomes are copied before cell division
occurs.
Cells produced from the division of a parent cell.
the cell that divides to produce daughter cells.
The formation of a new individual
The formation of a new individual only involving one
parent without fertilisation. Uses mitosis to produce
offspring genetically identical to the parent.
A sex cell (egg, sperm, pollen)
The joining / fusing of the nuclei of the gametes. Eg a
sperm and egg
A fertilised egg cell.
The ball of cells produced by cell division of the zygote. A
very early stage in the development of a new individual.
Different / alternative forms of a gene. Eg the gene could
be for hair colour, the different forms are blonde,
brown, black etc.
A cell or organism that is genetically identical to the
parent cell or organism.
Remove the nucleus from the cell.
In reproduction placing an embryo into the uterus lining
of a female animal to develop.
The organ (muscular sac) where the foetus develops
Surrogate mother
Offspring
B2.9 Stem cells
Embryonic stem cells
Stem cells
Differentiate
Adult stem cells
B2.10 Protein manufacture
Genetic code
Amino acids
Protein synthesis
Transcription
Translation
Messenger RNA (mRNA)
Uracil
Ribosome
Coding strand
Base triplets (codons)
Transfer RNA (tRNA)
Polypeptide
B2.11 Mutations
Mutation
Keratin
Enzyme
Haemoglobin
B2.12 Enzymes
Enzyme
Catalyst
Digestion
B2.13 Enzymes and
temperature PCA
B2.14 Enzyme action
Denature
Substrate
Specific
(also called womb).
A female organism that has had the embryo of a
different female placed in her uterus.
A person’ child or children, or an animals’ young. The
individuals that are produced through reproduction.
Cells that make up embryos and can be taken from
embryos to produce any kind of differentiated cell.
An unspecialised cell that can divide to produce more
stem cells or different kinds of specialised cell.
To become specialised, develop into different kinds of
cell that do specific jobs (red blood cell, nerve cell).
A stem cell found in differentiated tissue that can
produce a few kinds of differentiated cell.
The code produced by the sequence of bases in genetic
material eg DNA
Small molecule that is the building blocks of proteins.
The building up of a protein molecule by joining together
amino acids.
When a strand of mRNA is produced by complimentary
pairing of bases with one strand of DNA in the nucleus.
Transferring the code in mRNA sequence into a
sequence of amino acids on a ribosome.
The molecule formed during DNA transcription that
carries the code from the chromosome to the ribosome.
A base only found in RNA, which replaces the base
thymine found in DNA.
Small structures in the cytoplasm of a cell where mRNA
is translated into an amino acid chain.
During DNA transcription, the coding strand is the DNA
strand which has the same base sequence as the RNA
transcript produced.
A group of three bases that codes for a particular amino
acid.
RNA molecule that transfers the correct amino acid to
the ribosome during translation so that the protein it
codes for can be assembled.
A chain of amino acids linked by peptide bonds that will
form a protein.
A change in the base sequence of DNA.
A tough type of protein found in the skin, hair, and nails.
Proteins produced by living organisms that acts as
biological catalysts to speed up the rate of reactions.
The red iron-containing pigment found in red blood cells
that oxygen binds to.
See above
A substance that speeds up the rate of a reaction
without being used up in the reaction.
The breakdown of large insoluble food molecules into
small insoluble food molecules so they can be absorbed
into the blood.
To break down / change shape, as proteins denature as
temperatures increase.
The substance that an enzyme binds to and changes in a
chemical reaction.
An enzyme will only catalyse the reaction of one kind of
substrate.
Active site
Lock and key hypothesis
Denature
B2 Topic 2: Organisms and
energy
B2.15 Aerobic respiration
Respiration
Aerobic respiration
Glucose
Capillaries
Diffusion
Concentration gradient
Gas exchange
B2.16 Investigating the effects
of exercise PCA
Heart rate
Breathing rate
B2.17 Anaerobic respiration
Stroke volume
Cardiac output
Anaerobic respiration
Lactic acid
Excess post-exercise
oxygen consumption
B2.18 Photosynthesis
Starch
Photosynthesis
Stoma
The site on an enzyme molecule that has a specific shape
that holds the substrate molecule during the reaction.
Refers to the way an active site of an enzyme and
substrate fit together – like a lock and key.
To break down / change shape, as proteins denature as
temperatures increase.
Regarding enzymes, the active site of the enzyme
changes shape at high temperatures and so no longer
fits on to the substrate – making it unable t catalyse the
reaction.
Reactions that happens in all living cells in which glucose
is broken down to release energy.
Respiration that takes place with available oxygen.
A simple sugar that is broken down in cells to release
energy during respiration. It is also produced during
photosynthesis.
Tiny blood vessels with thin walls to allow diffusion of
substances into and out of the blood.
The random movement and spreading of particles.
When a solute (such as oxygen) is in high concentration
in one area than in another area.
A process in the lungs in which oxygen diffuses from the
lungs into the blood and carbon dioxide diffuses from
the blood into the lungs.
Heart rate, or heart pulse, is the speed of the heartbeat
measured by the number of heartbeats per unit of time usually beats per minute (bpm).
Breathing rate is the speed of breathing measured by the
number of breaths per unit of time -usually breaths per
minute.
The volume of blood the heart can pump out with each
beat.
The volume of blood the heart can pump out in one
minute, calculated by using the equation:
cardiac output = stroke volume x heart rate.
Respiration that takes place without oxygen present.
A chemical that gives the sour taste to yoghurt. A
product of anaerobic respiration. It can build up in
muscle cells causing cramp when there is little oxygen
available to respire aerobically.
Period of time after exercise in which a greater than
usual volume of oxygen is needed (when you stop
exercising you are still breathing heavily) to break down
and remove the lactic acid. Formally known as oxygen
debt.
A complex carbohydrate made up of thousands of
glucose molecules bonded together.
Chemical reaction that occurs in chloroplasts of leaf cells
to make the plants own food, where carbon dioxide and
water are combined to form glucose and oxygen. Light is
needed for this process.
(Stomata plural). A tiny hole / pore on the underside of
leaves which, when open, allow the diffusion of gases
into and out of the leaf.
Surface area to volume
ratio
Chloroplasts
Chlorophyll
B2.19 Factors affecting the
rate of photosynthesis
Light intensity
B2.20 Limiting factors
Elodea
Limiting factor
B2.21 Water transport
Root hair cells
Osmosis
Partially permeable
membrane
Active transport
Xylem
Phloem
Transpiration
Potometer
B2.22 Investigating osmosis
PCA
Sucrose
B2.23 Organisms and their
environment
Environment
Biodiversity
Ecosystem
Habitat
Distribution
Population size
Sampling
Random sampling
Representative sample
Pooter
The total amount of surface area of an object divided by
its volume. The surface area to volume ratio of a small
organism is larger than that of a large object of a given
shape.
Organelle in plant cells that contains chlorophyll, and is
where photosynthesis takes place.
Green pigment in chloroplasts that absorbs light energy
from the sun.
The brightness that is associated with light energy.
Canadian pondweed.
A single factor that when in short supply can limit the
rate of a process such as photosynthesis.
Cells found on plant roots that have thin extensions
(hairs). Water enters root hair cells by osmosis. The thin
extensions give a large surface area for the absorption of
water.
The diffusion of water molecules only from an area of
high concentration of water molecules to an area of low
concentration f water molecules through a partiallypermeable membrane.
A thin sheet of material that will allow certain small
molecules to diffuse through it (eg water) but not other
larger molecules.
Movement of molecules into the cell using energy from
respiration. This occurs against a concentration gradient
(from low to high concentration) and allows the cell to
build up a high concentration of certain molecules. Eg
the way plant root hair cells take in minerals.
Tissue made of dead hollow cells that transports water
and dissolved minerals from the roots to other parts of
the plant.
Living tissue that transports sugars around the plant.
The evaporation of water vapour from the surface
(usually leaves) of a plant.
A device used for measuring the rate of water uptake by
a plant.
Sucrose is made from glucose and fructose units:
Sucrose or table sugar is obtained from sugar cane or
sugar beets.
An organisms surroundings; made up of many different
factors such as air, water, soil and other living organisms.
The variety of species present within a given area.
An area in which all the living organisms and all the non
living features form a stable relationship that needs no
input from outside the area to remain stable.
The place where an organism usually lives.
The places in which a certain organism can be found in
an area.
The numbers of individuals of a species in a given area.
Looking at a small portion of an area or population.
A method of sampling where the locations are selected
randomly.
A sample that has approximately the same
characteristics as those of the whole study area.
A simple device used to collect small invertebrates.
Sweep net
Pond net
Pitfall trap
Quadrat
Systematic sampling
B2.24 Investigating the
Sampling techniques
distribution of organisms in an
ecosystem
B2 Topic 3: Common systems
B2.25 Fossils and evolution
Fossils
Fossil record
Evolution
B2.26 Growth
Pentadactyl
Growth
Percentile
Elongation
Differentiate
Stem cells
B2.27 Blood
Blood
Plasma
Red blood cell
White blood cell
Platelets
Haemoglobin
Tissue
Antibodies
A net used to collect insects from long grass or the
canopy of a tree by sweeping through the grass or
leaves.
A net used to collect aquatic organisms from ponds,
rivers and streams.
A trap used to catch small animals that move on the
ground. The animals are unable to escape.
A square frame of known area (such as 1m x 1m) which
is placed on the ground to get a sample of the organisms
living in a small area. Usually used to count plant species.
A method of sampling where the samples are selected
from the population at regular intervals (eg a sample
every metre).
The techniques / methods used by scientists studying
ecology to get samples of the living organisms in an area.
The preserved traces or remains of an organism which
lived a very long time ago.
The collection of fossils identified from different periods
of time that can be interpreted to form a hypothesis
about the evolution of life on Earth.
The development of new species over time through a
process of natural selection.
Five-fingered.
Increase in size, length and mass, as well as increase in
cell number.
The value of a variable below which a certain percentage
of observations fall. Eg, the 20th percentile of a set of
data indicates that 20% of the data points are the same
or lower than this value.
Process of getting longer.
To become specialised, develop into different kinds of
cell that do specific jobs (red blood cell, nerve cell).
An unspecialised cell that can divide to produce more
stem cells or different kinds of specialised cell.
Blood is a bodily fluid in animals that delivers necessary
substances such as nutrients and oxygen to the cells and
transports metabolic waste products away.
The liquid component of blood that carries all the
suspended cells and dissolved substances.
Biconcave disc shaped cells containing haemoglobin that
give the blood its red colour and carry oxygen around
the body to the tissues.
Several different types of cells that are all part of the
body’s defence system against disease.
Cell fragments that are important in the clotting
mechanism of the blood.
The red iron-containing pigment found in red blood cells
that oxygen binds to.
A group of specialised cells that wrk together to carry
out the same function eg muscle tissue
An antibody is a protein produced by the body's immune
system when it detects harmful substances, called
antigens, on microbes. The antibodies then neutralise or
destroy the microbe.
Specialised
Oxyhaemoglobin
Biconcave disc
Blood clot
B2.28 The heart
Organ
Heart
Deoxygenated
Oxygenated
Septum
Inferior vena cava
Superior vena cava
Aorta
Right atrium
Left atrium
Right ventricle
Left ventricle
Pulmonary vein
Pulmonary artery
Lungs
Valves
Tendons
B2.29 The circulatory system
Blood vessel
Arteries
Capillaries
Veins
Connective tissue
Organ systems
Circulatory systems
Has undergone differentiation to become a particular
cell type with a particular structure to fulfil a specific
function or job.
Compound formed when haemoglobin and oxygen
combine in the red blood cells and is then carried around
the body.
The shape of red blood cells to increase surface area to
volume ratio.
A mass of coagulated blood (changing to a harder gel or
solid), as within a blood vessel or at the site of an open
wound.
A group of different tissues working together to carry
out a particular function.
The organ that pumps blood around the body
Without oxygen.
With oxygen.
A membrane that separates the two sides of the heart.
A major vein leading into the heart. Brings deoxygenated
blood back from the lower part of the body to the heart.
A major vein leading into the heart. Brings deoxygenated
blood back from the upper part of the body to the heart.
A major artery leading away from the heart.
One of the four chambers of the heart. Receives blood
from the vena cava.
One of the four chambers of the heart. Receives blood
from the pulmonary vein.
One of the four chambers of the heart. Receives blood
from the right atrium and then contracts to pump blood
into the pulmonary artery to be taken to the lungs.
One of the four chambers of the heart. Receives blood
from the left atrium and then contracts to pump blood
into the aorta to be taken around the body.
Veins that carry oxygenated blood from the lungs to the
left atrium.
Arteries that carry deoxygenated blood from the right
ventricle to the lungs to collect oxygen.
The organ that is responsible for breathing and getting
oxygen into our bodies and ridding the body of carbon
dioxide.
Flaps of tissue in the heart that stop the blood flowing
backwards.
Tough string-like tissue that prevents the valves from
turning inside out.
Tubes that carry the blood around your body.
Blood vessels that carry blood away from the heart.
Tiny blood vessels with thin walls that allow diffusion of
substances into cells in tissues from the blood, and allow
waste substance to diffuse out of the cells into the blood
along a concentration gradient.
Blood vessels that carry blood back to the heart.
Connective tissue is a kind of animal tissue that supports,
connects, or separates different types of tissues and
organs of the body.
A group of organs working together to carry out a
particular function in the body.
Organ system involving the heart and blood vessels
B2.30 The digestive system
Digestion
Digestive system
Alimentary canal
Enzymes
Bolus
Saliva
Mouth
Teeth
Oesophagus
Stomach
Stomach acid
Peristalsis
Small intestine
Villus
Pancreas
Liver
Gall bladder
Large intestine
Rectum
Anus
Bile
Faeces
B2.31 Breaking down food
Carbohydrates
Proteins
Fats
Sugars
which oxygenates blood and moves it around the body.
The breakdown of large insoluble food molecules into
small soluble food molecules that can be absorbed into
the blood stream.
The system of organs involved in the digestion of food.
Muscular tube that runs from the mouth to the anus and
includes oesophagus, stomach etc
Biological catalysts that speed up the rate of reactions in
the body, including the breakdown of food.
A ball shaped mass of chewed food that you swallow.
Liquid substance that lubricates food making it easier to
swallow and contains amylase which begins the
breakdown of carbohydrates.
Hole where food is first placed to be chewed and
swallowed.
Hard structures in the mouth that break up and grind
food into smaller pieces to increase surface area for
digestive enzymes to work on.
Muscular tube which pushes food from the mouth to the
stomach by using peristalsis.
Organ that makes stomach acid and protease. Muscular
sac that churns up food using peristalsis.
Acidic substance that can kill micro-organisms in food
and drink.
Waves of muscular contraction that move food along the
alimentary canal.
Organ where digestion is completed and nutrients are
absorbed.
Plural is villi. Finger-like projections / folds covering the
inside lining of the small intestine which greatly
increases surface area for the absorption /diffusion of
food molecules into the blood stream.
Organ that makes digestive enzymes and secretes them
into the small intestine.
Makes bile. Liver breaks down digested food molecules
even further, r can build them back up into larger
molecules.
A small organ that stores the bile made by the liver and
releases into the small intestine via the bile duct
Organ that absorbs water from undigested material.
Where faeces is stored until it is ready to be egested
from the body.
Where faeces (undigested food) is passed out of the
body (egested).
An alkaline substance made by the liver and helps
emulsify fats.
Undigested food and waste material which was not
absorbed into the bloodstream. (Pooh!)
Compounds made from carbon, hydrogen and oxygen
used for energy by organisms.
A polymer made up of amino acids, containing hydrogen,
carbon, oxygen and nitrogen. Genes carry the
instructions for making proteins.
Large food molecules that can be broken down into fatty
acids and glycerol.
A group of compounds made from carbon, hydrogen and
Starch
Amylase
Carbohydrase
Protease
Lipase
Pepsin
Amino acids
Fatty acids
Glycerol
Emulsion
B2.32 Villi
Emulsify
Villi
Large surface area
Absorbed
Insoluble
Soluble
Concentration gradient
Coeliac disease
B2.33 Enzyme concentration
PCA
B2.33
Capillary network
Amylase
Probiotics
Prebiotics
Functional foods
Lactobacillus
Bifidobacteria
Plant stanol esters
Cholesterol
Oligosaccharides
oxygen used for energy by organisms.
A complex carbohydrate made up of thousands of
glucose molecules bonded together.
A carbohydrase enzyme found in saliva which breaks
down starch into simple sugars.
An enzyme that catalyses the breakdown of
carbohydrates such as starch into simpler sugars.
An enzyme that catalyses the breakdown of proteins into
amino acids.
An enzyme that catalyses the breakdown of fats or oils
into fatty acids and glycerol.
An example of a protease enzyme found in the stomach.
The building blocks of proteins
A molecule that makes up fats or oils, along with
glycerol.
A molecule that makes up fats or oils, along with fatty
acids.
A mixture in which particles of one liquid are suspended
in another liquid.
To turn into an emulsion.
Finger-like projections / folds covering the inside lining
of the small intestine which greatly increases surface
area for the absorption /diffusion of food molecules into
the blood stream.
Large amount of exposed area.
The movement of a substance, such as a liquid or solute,
across a cell membrane by means of diffusion or
osmosis.
Not able to dissolve
Able to dissolve
When a solute (such as oxygen) is in high concentration
in one area than in another area.
A condition where the immune system attacks the
substances in gluten, causing damage to the villi lining
the small intestine.
A network of capillaries – lots of them in close proximity.
A carbohydrase enzyme found in saliva which breaks
down starch into simple sugars.
Foods containing live bacteria that produce lactic acid in
the gut and may improve the health of your digestive
system.
Substances which cannot be digested by human
digestive enzymes but which act on food for probiotic
bacteria in the intestine.
Foods that are not eaten for nutritional value but which
claim to make you healthier.
Example of probiotic bacteria.
Example of probiotic bacteria.
Oily substances found in plants that appear to lower
blood cholesterol levels in people.
A fat made in the liver and carried around the body in
blood. High levels increases the risk of heart disease.
A type of carbohydrate which is a common prebiotic.