Biology exam revision

Question 1

What is health?

Answer 1

Health is a state of physical and mental well being.

Question 2

What is communicable diseases?

Answer 2

Diseases that can be transmitted from one person to other another. e.g: HIV gonorrhoea, and Covid - 19

Question 3

What are non communicable diseases?

Answer 3

Diseases that cannot be transmitted from one person to another. e.g: lung cancer diabetes parkinsons disease and hypertension.

Question 4

What are the differences between bacteria and virus?

Answer 4

Bacteria
1. Bacteria can be used to make food, treat sewage, and make medicines.
2. Pathogenic bacteria are the minority
3. Produce toxins
Virus
1. Takes over cells in the body making them reproduce and destroying other cells in our body.
2. Viruses are all pathogenic
3. No benefits in using viruses

Question 5

What are the ways we can prevent getting diseases through hygiene?

Answer 5

1. Washing hands after using the toilet
2. Using disinfectants on kitchen work surfaces
3. Keeping raw meat away from food that is eaten to prevent the spread of pathogens.
4. Cover mouth when coughing or sneezing
   5.Maintaining the hygiene of people or agricultural machinery helps to prevent the spread of plan diseases.

Question 6

Why is isolating infected individuals important to control a disease?

Answer 6

The fewer people come into contact with the infected person the less likely for the pathogen to be passed on.

Question 7

How can we prevent the spread of disease through controlling vectors?

Answer 7

Vectors can be destroyed to prevent the spread of disease or reduce it.

Question 8

How does vaccination work?

Answer 8

1. A small amount of the inactive/dead form of the pathogen is injected into the body.
2. The immune system produces antibodies to fight against the pathogen.
3. Memory cells are retained so if the same pathogen attacks it will be prepared.

Question 9

What are the ways of spread, symptoms, treatment and ways to prevent measles?

Answer 9

1. Spread: airborne - inhaling droplets from coughs and sneezes.
2. Symptoms: fever and red skin rash
3. Treatment: no treatment only able to relieve symptoms
4. Prevention: vaccinate and isolate those who are infected.

Question 10

What are the ways of spread, symptoms, treatment and ways to prevent HIV?

Answer 10

1. Spread: sexual contact and exchange of bodily fluids.
2. Symptoms: causes the immune system to be badly damaged making it unable to fight against diseases.
3. Treatment: no treatment, but the development of antiretroviral drugs help prevent the development of aids and spread of the virus.
4. Ways to prevent: encouraged use of contraception such as condoms and screen blood used for transfusion.

Question 11

What are the ways of spread, symptoms treatment and ways of prevention of the tobacco mosaic virus?

Answer 11

1. Spread: contact and vectors.
2. Symptoms: distinct mosaic pattern of discoloration on leaves . Affects the growth of the plant and reduce the yield of the plant as the affected parts of the leaf cannot photosynthesize.
3. Treatment: no treatment
4. Ways to prevent: good field hygiene and good pest control.

Question 12

What are the ways of spread, symptoms, treatment and ways to prevent spread of salmonella food poisoning?

Answer 12

1. Spread: eating undercooked food and eating food prepared in unhygienic conditions
2. Symptoms: fever, abdominal cramps, vomiting and diarrhoea.
3. Treatment: rest and hydration drinks sometimes antibiotics.
4. Ways to prevent spread: vaccinate poultry against salmonella, keep cooked food away from raw meat, and avoid washing raw chicken.

Question 13

What are the ways of spread, symptoms, treatment and ways to prevent the spread of Ghonorrhoea?

Answer 13

1. Spread: sexually transmitted disease (unprotected sexual contact with an infected person.)
2. Symptoms: a thick green or yellow discharge from the vagina or penis.
3. Treatment: antibiotics
   4.Ways to prevent: encouraged use of contraception and treating all infected individuals to prevent community spread.

Question 14

What are the ways of spread, symptoms, treatment and ways to prevent spread of agrobacterium tumefaciens?

Answer 14

1. Spread: enters plant wounds from infected soil and tools.
2. Symptoms: mass of unspecified cells often between the root and the shoot of the plant.
3. Treatment: none
4. Ways to prevent spread: destroy infected plants, clean tools and use resistant plant types.

Question 15

What are the ways of spread, symptoms, treatment and ways of spread of the rose black spot?

Answer 15

1. Spread: airborne carried by the wind and then spread over the plant after it rains.
2. Symptoms: black or purple spots on the leaves causing the area on the leaves unable to photosynthesize causing it produce fewer leaves or flowers.
3. Treatment: no cure- fungicides can be sprayed on the leaves to kill the fungus.
4. Ways to prevent the spread: remove and burn infected leaves and spray fungicides on infected leaves to help kill the fungus.

Question 16

What are the ways of spread, symptoms, treatment and ways to prevent spread of malaria?

Answer 16

1. Spread: Infected mosquito bites human causing the protist to enter the blood stream.
2. Symptoms: recurrent episodes of fever and shaking.
3. Treatment: drugs
4. Ways to prevent the spread: using insecticides to kill mosquito, preventing the mosquito from breeding by removing standing water.

Question 17

How does the skin protect us from pathogens?

Answer 17

Skin covers the body and acts as a barrier, preventing bacteria from entering into our body.

Question 18

How does the nose protect pathogens from entering our body?

Answer 18

Hairs in the nose produce a sticky liquid called mucus that traps particles in the air which may contain pathogens.

Question 19

How does the trachea and bronchi prevents pathogens from entering our body?

Answer 19

The cilia beat the mucus up to the back of the throat where it is swallowed.

Question 20

How does the stomach defends against pathogens?

Answer 20

Stomach acid kills the microorganisms in our food.

Question 21

What are the physical defenses of plants?

Answer 21

The cell wall helps resist invasion against microorganisms, waxy cuticle, bark, leaf fall.

Question 22

What are the chemical defenses of plants?

Answer 22

Produce antibacterial chemicals that protect them against invading pathogens.

Question 23

What are the defenses of plants against herbivores?

Answer 23

Produce poisons to deter herbivores, thorns, drooping or curling when touched and mimic unhealthy plants tricking animals to avoid them.

Question 24

What is herd immunity?

Answer 24

Herd immunity is if enough people get vaccinated, the spread of the pathogen is greatly reduced or may even disappear.

Question 25

What are examples of pain killers?

Answer 25

Paracetamol and aspirin

Question 26

How do antibiotics work?

Answer 26

Antibiotics like penicillin act by damaging the bacterial cells without damaging our own cells.

Question 27

What are the disadvantages about antibiotics?

Answer 27

1. Antibiotics cannot kill viral pathogens so they have no effect on diseases that are caused by viruses.
2. Strains of bacteria are evolving to be more resistant to antibiotics.

Question 28

What are some drugs developed from plants?

Answer 28

Digitalis(strengthens the heartbeat) and aspirin(painkiller)

Question 29

What are the functions of white blood cells?

Answer 29

To fight pathogens.

Question 30

What are the 2 types of white blood cells?

Answer 30

Lymphocytes and phagocytes

Question 31

What do the lymphocytes do?

Answer 31

Lymphocytes produce antitoxins to neutralizes toxins, and produce antibodies that target and bind to antigens on the pathogens surface.

Question 32

How the phagocytes destroy pathogens?

Answer 32

1. phagocytes are attracted to an infected area.
2. Phagocytes engulf the pathogen.

Question 33

What does a white blood cells do?

Answer 33

They fight against harmful pathogens.

Question 34

What are the 2 types of pathogens?

Answer 34

Lymphocyte and phagocyte.

Question 35

What does lymphocyte do?

Answer 35

They produce antitoxins to neutralize toxins or produce antibodies that bind to specific antigens on the surface of pathogens.

Question 36

How does phagocyte destroys pathogens?

Answer 36

1. White blood cells are attracted to the area of infection.
2. Phagocytes cells engulf pathogens.
3. Phagocytes uses enzymes to digest the pathogen.

Question 37

What is herd immunity?

Answer 37

If a large portion of a population is vaccinated against a disease, the disease is less likely to spread even if there are some unvaccinated individuals.

Question 38

How are monoclonal antibodies produces?

Answer 38

1. Mice are injected to stimulate the production of lymphocytes that make specific antibodies.
2. Myeloma cells are cultured. These cells can divide and grow endlessly.
3. Lymphocytes and myeloma cells are fused together to create a hybridoma which can keep reproducing even after making antibodies.
4. A large amount of monoclonal antibodies can be collected and purified for use.

Question 39

What are the uses of monoclonal antibodies?

Answer 39

1. Diagnostic testing- can be used to measure the levels of a particular in the blood or to detect pathogens.
2. Pregnancy tests - monoclonal antibodies can be used to detect pregnancy in urine.
3. Research- Specific cells and tissues can be detected by using monoclonal antibodies to bind them to a fluorescent dye.
4. Treatment- can deliver toxic chemicals and drugs specifically to cancer cells, limiting their harm to other cells.