Download intervention session 3 biology 1 - science

EXAM REVIEW
Keywords: Suggest, Use information, Explain, Conclude,
Calculate, Describe, Evaluate
GCSE Core Biology
EXAM REVIEW
Learning Objectives:
• Understand what different questions are asking.
• Know what answers are expected by AQA.
I will be successful in this lesson if I can:
• State what information is required to answer AQA set
questions (Grade C)
• Explain what ‘understanding’ questions are asking for
(Grade C).
• Identify the language sought for when answering
examination questions (Grade B).
• Structure long answers appropriately (Lvl B).
• Identify strengths and weaknesses in example answers
and explain why and where marks would be appropriate
(Grade A).
GCSE Core Biology
EXAM REVIEW
5 mins:
On your own write down as many bits of
information that you think belongs in that
question.
10 mins:
Swap your paper with your partner and add to
their paper.
GCSE Core Biology
EXAM REVIEW
Speak to others in the room to find the answers to
the questions that you have no bits of
information on.
Please no
more than
5mins
GCSE Core Biology
EXAM REVIEW
Let’s review the key points for Infectious Diseases 1
•Pathogens are micro-organisms that cause infectious diseases. Bacteria
reproduce inside the body producing toxins that get to such a level that
they make us feel ill. Viruses live inside the body cell.
•Semmelweiss discovered that infection could be transferred between
patients, but that washi9ng hands between treating patients helped to
stop infection transfer. It was many years before his views were accepted
•Its best to stop pathogens getting into your body, if they do then the
white blood cells either 1) ingest them (digest & destroy), 2) produce
antibodies to help destroy them or 3) produce antitoxins to counteract the
toxins the pathogens produce.
•Antibiotics kill bacteria eg penicillin. Viruses are more difficult to kill
because they live inside cells and killing them means you also kill the
healthy cells. Painkillers make you feel better but do not kill the pathogen
•If a pathogen changes by mutation or natural selection, then it is more difficult to
control as the drugs that were used to destroy it may no longer work now that it
has changed. Very few people are immune to these new pathogens & so disease
spreads quickly within a country (epidemic) or across countriesGCSE
(pandemic).
Core Biology
EXAM REVIEW
ASSESSOR TIPS
• Pathogens need to reproduce before they make enough toxins to make
you ill.
• Semmelweiss had trouble persuading his peers to wash their hands as
his peers did not want to be the reason why so many young mothers
were dying.
• Must remember all 3 things that the white blood cell does but never
refer to ingestion as ‘EAT’ this is wrong.
• Viruses are harder to get rid of because they reproduce inside the body
cells so if you destroy the virus you also destroy the healthy body cell.
• Bacteria do not have a brain so they don’t decide or want to mutate –
they just do.
• Make sure you know how bacteria become resistant to antibiotics by
natural selection.
GCSE Core Biology
Let’s review the
keyREVIEW
points for Infectious Diseases 2
EXAM
•MRSA is a superbug that has evolved in hospitals through natural
selection and is resistant to commonly used antibiotics.
•It costs a lot of money & time to develop new medicines. They must be
tested to see that they are not toxic, they are effective against the disease
& that they can be stored for a long time. These tests are carried out in
laboratories on animals and then on humans.
•If these tests are not thorough then a new medicine may have a
dangerous side effect eg thalidomide was use din 1950s as a sleeping pill
& also helped to prevent morning sickness in pregnant women. It was not
tested thoroughly enough and women started to give birth to babies with
sever limb abnormalities. It is now used as an effective treatment for
leprosy.
•You can be immunised (a vaccine is made of dead or an inactive form of
the disease) to stop you from getting a disease.
•The white blood cells are stimulated to make antibodies (to destroy the
pathogens antigens). Now your body can respond to this pathogen by
rapidly to produce the correct antibody which would destroy the
pathogen if infected.
GCSE Core Biology
EXAM REVIEW
ASSESSOR TIPS
•
Mutation takes place in an instant whereas natural selection is a gradual
process over years & requires the genes to be passed onto the next
generation.
• It is important to test new medicines on animals first to see if they are
toxic. Some people are against the use of animals for this. You must be
able to argue both sides of this argument.
• A vaccine is made of a dead or inactive form of the pathogen
GCSE Core Biology
Let’s review theEXAM
key points
REVIEWfor Adaptation for survival
•If animals were not adapted to survive in the areas they live, they would
die.
•The artic is cold & bleak but animals have a large volume to when
compared to their surface area (small ears). They also have white fur
(camouflaged), thick coat, thick fat layer under the skin (blubber) to
conserve heat.
•Bigger animals (eg elephants) have larger surface area compared to their
volume which means they can conserve heat more easily but its also
more difficult for them to lose heat. In the case of the elephant the wrinkly
skin increases the surface area so the elephant can lose heat.
•In dry conditions, animals are adapted to conserve water & stop getting
too hot. So they may hunt or feed at night to remain cool during the day.
•The white blood cells are stimulated to make antibodies (to destroy the
pathogens antigens). Now your body can respond to this pathogen by
rapidly to produce the correct antibody which would destroy the
pathogen if infected.
GCSE Core Biology
Let’s review theEXAM
key points
REVIEWfor Adaptation for survival
•Plants compete for light, water & nutrients. In hot, dry areas they have
long roots or widespread roots or thick stems or leaves or no leaves. Eg
in woodlands, some plants will flower before the trees so they can get the
sunlight first.
•Some plants have developed thorns, poisonous chemicals & warning
colours to put animals off. Some plants spread their seeds over a wide
area so they do not compete with their offspring.
•Animals compete for water, food, space, mates & breeding sites. An
animals territory is large enough for it to find food, water & have enough
space for breeding.
•Predators compete with their prey because they want to eat them. Prey
animals compete with each other as they want to escape predators & find
food. Both predators & prey use camouflage.
•Some animals use warning colours so that they are not eaten.
GCSE Core Biology
EXAM REVIEW
ASSESSOR TIPS
• You must understand surface area:volume ration. The larger the
animal, the smaller its surface area compared to its volume.
• Adaptations are not just to do with what the animal looks like it also
has to do with their behaviour.
• A vaccine is made of a dead or inactive form of the pathogen.
• There are many ways that plants conserve water in dry areas including
waxy leaves, extensive roots, small leaves, water storage in stems.
• There are many ways animals adapt including colour (for camouflage &
to attract mates) speed to catch food & escape.
• Plants compete by both their structures & flowering habits. Root
systems can provide much water for the plant & early or late flowering
can also allow the plant to compete for sunlight (because other plants
are still dormant)
GCSE Core Biology
Let’s review theEXAM
key points
REVIEWfor Variation
•Animals are more difficult to clone. Embryo transplants are used to clone
animals. In this process, embryos are split into smaller groups of cells
and then each group is allowed to develop in a host animal. Each a clone
of one another but not the original parent
•Sexual reproduction involves the fusion of the sex cells (gametes) which
causes the genetic information to mix forming a new individual that is
similar but different to both parents. Some human characteristics are
controlled by a single pair of genes eg attached/unattached ear lobes,
dimples, straight/curved thumbs.
•Asexual reproduction does not involve the fusion of the sex cells
because all the genetic information comes from the one parent & so the
offspring are identical to the parent. These are called clones.
•Cloning can produce new individuals with the characteristics that you
want. In plants this process is cheap and effective. They can be cloned by
cuttings that you grow, or taking groups of cells & growing them under
special conditions (tissue culture).
GCSE Core Biology
Let’s review theEXAM
key points
REVIEWfor Variation
•Genetic information from parents are past onto their offspring these are
contained within the male & female sex cells (gametes). This occurs by
DNA (a large molecules made up of smaller molecules). DNA makes
genes, genes make chromosomes. These genes control the development
of the characteristics in the offspring.
•Fusion & adult cell cloning are also used to clone animals. In this
process, the nucleus of the animal you want is placed into a empty egg
cell which is then developed in a different animal.
•Genetic engineering involves changing the genetic make-up of an
organism. The genes are cut out of the chromosome of an organism
using an enzyme, the genes are then placed in the chromosome of
another organism (of the same species or an organism with desired
characteristics or a different species)
•The gene to produce insulin in humans can be placed in bacteria
(actually the DNA ring called a plasmid) so that the bacteria produce the
insulin which we can then collect for use.
•Many people arguie whether or not genetic engineering is right.
GCSE Core Biology
EXAM REVIEW
ASSESSOR TIPS
• It is the individual genes that control the characteristics of the
offspring. Chromosomes are simply made up of genes.
• Sexual reproduction leads to variation because the male & female
gametes mix to produce a new individual. Asexual reproduction does
not produce variation because the offspring are genetically identical to
the parents.
• Know why clones are identical to their parents & how the different
types of cloning work.
• You must be able to write a balanced argument for cloning.
• It is the gene that controls how an organism develops. If you place a
gene in a new organism it will develop that characteristic (the
characteristic of the gene).
GCSE Core Biology
EXAM REVIEW
Learning Objectives:
• Understand what different questions are asking.
• Know what answers are expected by AQA.
I will be successful in this lesson if I can:
• State what information is required to answer AQA set
questions (Grade C)
• Explain what ‘understanding’ questions are asking for
(Grade C).
• Identify the language sought for when answering
examination questions (Grade B).
• Structure long answers appropriately (Lvl B).
• Identify strengths and weaknesses in example answers
and explain why and where marks would be appropriate
(Grade A).
GCSE Core Biology