Yr9 AQA B1 Revision 2015

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Biology Revision Starter: What do each of these things do? • White blood cells • Antibodies • Pathogen • Antigen molecules • Antibiotics

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Revision powerpoint for B1.1 unit of AQA Core Science

Transcript of Yr9 AQA B1 Revision 2015

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Biology RevisionStarter: What do each of these things do?

White blood cellsAntibodiesPathogenAntigen moleculesAntibioticsWhite blood cellsare found on the surface of pathogens. They allow white blood cells to detect if they are foreign to the body.Antibodiesproduce antibodiesPathogenkill pathogensAntigen moleculesare medicines (drugs) which kill bacteria but not viruses.Antibioticsare infectious micororganisms. They can be bacteria or viruses.

White blood cells produce antibodies.

Antibodies kill pathogens.

Pathogens are infectious micororganisms. They can be bacteria or viruses.

Antigen molecules are found on the surface of pathogens. They allow white blood cells to detect if they are foreign to the body.

Antibiotics are medicines (drugs) which kill bacteria but not viruses.Year 9 test next week!Write this in your planners:Revise Biology, Chemistry and Physics ready for year 9 test next Monday (29/06/15).Topics to reviseBiology- We will revise this in Mondays lesson

Diet and exercisePathogens and AntigensWhite blood cells and AntibodiesVaccination

Physics- We will revise this in Thursdays lesson

Conduction, convection and radiationParticles

Chemistry- We will revise this in Fridays lesson

AtomsIonsBacteria and virusesWhat is the difference between a bacteria and a virus?

How do they each make you feel ill?Bacteria

This is a pin with bacteria growing on it.Structure of bacteria

Bacteria produce toxins. These are the poisons that make you feel ill

Viruses these are much smaller

Virus invade body cells and then hijack the cells DNA to reproduce. This can cause massive cell damage.

Virus proteins are synthesised inside the cell.B1.1 Diet and exercisea) A healthy diet contains the right balance of the different foods you need and the right amount of energy. Carbohydrates, fats and proteins are used by the body to release energy and to build cells. Mineral ions and vitamins are needed in small amounts for healthy functioning of the body. A person is malnourished if their diet is not balanced. This may lead to a person being overweight or underweight. An unbalanced diet may also lead to deficiency diseases or conditions such as Type 2 diabetes.b) A person loses mass when the energy content of the food taken in is less than the amount of energy expended by the body. Exercise increases the amount of energy expended by the body.c) The rate at which all the chemical reactions in the cells of the body are carried out (the metabolic rate) varies with the amount of activity you do and the proportion of muscle to fat in your body. Metabolic rate may be affected by inherited factors.d) Inherited factors also affect our health; for example cholesterol level.e) People who exercise regularly are usually healthier than people who take little exercise.

ImmunisationStarter Answer these questions in your books:Which infectious diseases have you had?When you had a disease why did you recover?If you have a disease are you likely to have it again?If you had the measles and came in contact with someone who had chicken pox, would you be protected?12Discuss these questions with your partnerWhich infectious disease have you had?- Measles, chicken-pox, rubella/German measles, mumps etc.

When you had a disease why did you recover? White cells produced sufficient antibodies to kill pathogen

If you had the measles and came in contact with someone who had chicken pox would you be protected? No each has different antigens which need different antibodies. 13Natural acquired immunityThese actions by white blood cells is described as natural acquired immunity.

It takes a few days before the response is large enough to fight off an infection. During this time, damage to the body tissues will happen and you will feel the symptoms of the infection. With most infections you will produce enough antibodies to kill the pathogens causing the infection and the symptoms disappear. Once this happens your immune system switches off its response to this infection.14Immunity and vaccinationIf you have a disease are you likely to have it again?

Explain.15If you have a disease are you likely to have it again?

Explain.

No. The white blood cells remember the pathogen. If you get infected a second time your immune system is already prepared for the pathogen and can quickly make enough antibodies to kill the infection before any symptoms are felt, giving immunity to this pathogen.

16VaccinationWhat is vaccination ?

Name some diseases which we can be vaccinated against.

Activity : Can you sort out the statements to give the sequence of how a vaccine can give immunity to a disease.17VaccinationWhat is vaccination ?

A vaccine is given which contains dead or inactivated pathogens. This is given by injection or by mouth. This stimulates antibody production.

Name some diseases which we can be vaccinated against?

polio, measles, Rubella/German measles, Mumps, Tetanus, whooping cough, Tuberculosis, Diptheria.

18Write in order to give correct sequence of how a vaccine can give immunity to a disease.White blood cells will engulf and digest antigens

Injection of vaccine into blood

White blood cells (Lymphocytes) produces antibodies to bind with invading antigen

Dead or inactive pathogen(vaccine prepared)

The lymphocytes will remain and remember in the blood giving immunity to this pathogen (memory cells)19Sequence of how a vaccine can give immunity to a disease.Dead or inactive pathogen (Vaccine prepared)

Injection of vaccine into the blood

White blood cells (Lymphocytes) produces antibodies to bind to invading antigen

White blood cells will engulf and digest antigens

The lymphocytes will remain and remember in the blood giving immunity to this pathogen (memory cells)20What are the advantages of this form of active immunity over naturally acquired immunity?

This avoids having the illness in order to gain immunity.

More antibodies will be produced in a shorter length of time . The antibodies quickly reach the level that will kill off the infection before any symptoms are seen21What is an advantage of vaccinating a wide number of people in a population?What is an advantage of vaccinating a wide number of people in a population?

It reduces the ability of the disease to spread and prevents a pandemic.If a large proportion of the population is immune to a pathogen, the spread of the pathogen is very much reduced. Explain.If a large proportion of the population is immune to a pathogen, the spread of the pathogen is very much reduced. Explain.

Once a successful vaccine for a disease becomes available and used in enough of the population, that disease will no longer occur or become very rare. This is because the disease cannot be passed on because it cannot find a new host.Why cant a vaccine be developed for the common cold?

Why cant a vaccine be developed for the common cold?The common cold is caused by a virus. It constantly mutates and changes giving different antigens on its surface. The mutations occur too quickly for a virus to be produced or used.

For which infectious disease is there currently no vaccine available?

For which infectious disease is there currently no vaccine available?HIV/Aids

The MMR is a triple vaccine against which diseases?

The MMR is a triple vaccine against which diseases?Measles, mumps and Rubella (German measles)Plenary Quiz. (Answers at the end)1. What is a pathogen? DiseaseA disease-causing microorganismA type of disease.

2. Which of these is one of the main problems with bacteria? They are killed by antibiotics.They produce toxins.They cause measles and mumps in young children.

3. What is one of the functions of white blood cells?To carry oxygen in the bloodstreamTo produce antigens that destroys pathogensTo ingest and destroy pathogens

4. What is going into the body in a vaccination? Antibiotics against a disease.Dead or weakened pathogenLive pathogen to stimulate the immune system.

Answers:1. A disease-causing microorganism2. They produce toxins.3. To ingest and destroy pathogens4. Dead or weakened pathogen