Microbes Defence Against Disease

Question 1

Fungi structure

Answer 1

Network of threads

Question 2

Fungi examples

Answer 2

Mushroom, toad stools and moulds

Question 3

Virus structure

Answer 3

Head capsule, that contains DNA, with a long tail with an end plate attached

Question 4

Examples of virus

Answer 4

Measles, mumps, chicken pox and colds

Question 5

Bacteria structure

Answer 5

Cocci are spherical, bacilli are rod shaped, spirochètes are spirals

Question 6

Examples of bacteria

Answer 6

Salmonella, staphylococcus and lactobacillus

Question 7

What is Aseptic technique

Answer 7

When studying bacteria and other microbes effectively, scientists must stick to a set of rules referred to as aseptic technique. It ensures the bacteria they are looking at is from one spurce

Question 8

Example of where bacteria would be studied

Answer 8

Environmental health lab

Question 9

Method of aseptic technique

Answer 9

Set up Bunsen on heat proof mat

Place pétri dish close to Bunsen

draw across the base of the dish to divide it into 4 equal sized areas

Carefully unscrew lid from bottle of agar

Flame mouth of bottle in Bunsen flame

Lift lid of pétri dish just enough to pour agar in

Close lid as quickly as possible

Gently move dish to make sure the bottom of the dish is completely covered in agar

Leave to set for 10 mins

Decide on 4 sites from where you want to obtain your microbes

Use cotton bud to obtain microbes on your chosen surface

Return to work area, lift lid of pétri dish and carefully stroke the cotton bud over the surface of the agar. Make sure not to damage the surface of the agar

Replace the lid of pétri dish

Seal dish with sellotape and label your initials, the date and the source of your microbes

Place in the incubator upside down

Question 10

Precautions when doing aseptic technique

Answer 10

Use sterile equipment

Work close to a Bunsen

Wash hands

Flame mouth of the bottle of agar

Wear gloves and a mask

Place in incubator upside down (so all condensation falls down and doesn’t affect results)

Question 11

What is a pathogen

Answer 11

A microbes which causes sickness and disease

Question 12

4 ways pathogens spread

Answer 12

Airborne (eg: Covid, tuberculosis and cold)

Water (drink infected water eg: typhoid and cholera)

Direct contact (touch eg: chicken pox)

Indirect contact ( eat infected food eg: salmonella)

Question 13

Defences against pathogens

Answer 13

Skin forms a protective barrier to prevent microbe entry.

Microbes in food will enter the stomach and hydrochloric acid will kill bacteria

Cilia in kings produce mucus in lungs and trap bacteria. They want this back to the stomach to be killed by hydrochloric acid

Tears have antiseptic fluid that kills microbes

Platelets in blood clot and form a scab if skin is broken

White blood cells destroy microbes

Question 14

What are phagocytes

Answer 14

Type of white blood cell responsible for “mopping up” infected cells and pathogens that have entered the body. They go around ingesting and digesting microbes.

Question 15

What are phagocytes like

Answer 15

PAC man

Question 16

4 stages of phagocytosis
D
M
E
D

Answer 16

The phagocyte detects a pathogen

It then migrates and attaches itself to it

Cytoplasm surrounds and engulfs the pathogen

Pathogen is then digested, indigestible residue is removed

Question 17

What is a outbreak

Answer 17

A sudden rise in the number of cases of a disease. It may occur in a community or geographical area, it may last a few days, weeks or even several years.

Question 18

Example of outbreak

Answer 18

Ecoli or flu

Question 19

What is a epidemic

Answer 19

When a infectious disease spreads rapidly to many people

Question 20

Example of epidemic

Answer 20

SARS and EBDA

Question 21

Pandemic definition

Answer 21

Global outbreak, affects wider geographical area, often worldwide. Infects a greater number of people than a epidemic. Often caused by a new virus or a strain of virus that has not circulated for a long time

Question 22

Example of pandemic

Answer 22

Covid 19

Question 23

What are lymphocytes

Answer 23

Type of white blood cell

Produce antibodies

When lymphocytes encounter a microbe it will produce antibody Molecules, these join to a specific part of the microbe called the antigen. This causes the microbe to rupture or group them together. Rupture causes them to die, there numbers therefore decrease overtime and infection is reduced. Grouping pathogens in 1 place allows phagocyte cells to digest a larger number in a efficient way it also prevents spread to other parts of the body

Question 24

For every different ……. You encounter there is a new ………. Produced. ………. Are specific. The ………. Of an ……… will take time- during this period you will feel I’ll or have ……. Of the infection

Answer 24

Microbe

Antibody

Antibodies

Production

Antibody

Symptoms

Question 25

What happens when you have already experienced the type of pathogen

Answer 25

The immune system has already produced a specialised cell called a memory cell. These remain in your body for the rest of your life meaning that if you are infected a 2nd time your immune system can respond much more quickly- so fast you won’t have symptoms

Question 26

Who developed the first vaccination

Answer 26

Edward jenner

Question 27

What are vaccinations

Answer 27

They work by artificially activating lymphocytes to produce antibodies against a disease. You will get vaccinated by a harmless toxin from the Microbe causing the disease.

Question 28

What are antibiotics

Answer 28

A group of chemicals that stop bacteria growth. They are commonly to treat infections and are prescribed by doctors as tablets, creams and medicines. First antibiotic discovered by Alexander Fleming

Question 29

What are superbugs

Answer 29

Are bacteria that are resistant to certain antibiotics. Eg: MRSA and C.difficile