Science exam revision

Question 1

Define the word disease?

Answer 1

A disease is harmful to the body

Question 2

What is the difference between infectious and non-infectious diseases?

Answer 2

Infectious is spreadable and non infectious you cant spread.

Question 3

Name 3 infectious and 3 non-infectious diseases?

Answer 3

Flu, covid and measles. and non infectious cancer, diabetes, stroke.

Question 4

Describe 3 ways disease causing microbes can spread

Answer 4

Mouth, airdroplets, sexual contact.

Question 5

What is a host?

Answer 5

Organism that carries the pathogen and can spread to infect others.

Question 6

What is the name given to a disease causing microbes?

Answer 6

An organism that can spread disease but is not harmed itself. E.g. mosquitoes carrying the
pathogen that causes malaria and will spread when they bite.

Question 7

What is the name given to a disease causing microbes?

Answer 7

Pathogen

Question 8

Why are viruses not classified as living?

Answer 8

Viruses require a host cell to replicate. Without a living host cell, the virus is unable to replicate.

Question 9

What is and antibiotic? Give an example.

Answer 9

Examples include penicillin. These are chemicals that break down the bacterial cell in the body
and destroys bacteria.

Question 10

How do bacteria reproduce?

Answer 10

Through binary fission

Question 11

What conditions do Bacteria like to reproduce?

Answer 11

Warm and wet/damp

Question 12

Name 2 diseases caused by bacteria

Answer 12

Salmonella (food poisoning), chlamydia, whooping cough, tuberculosis.

Question 13

What is antibiotic resistance?

Answer 13

When antibiotics have no effect in the body as the bacteria have developed a resistance to
them.

Question 14

How do resistant bacteria (super bugs) develop?

Answer 14

It becomes resistant because it has adapted

Question 15

Describe a virus.

Answer 15

Avirusis a tiny, infectious particle that can reproduce only inside a host cell.

Question 16

Name 2 diseases caused by viruses.

Answer 16

Chicken pox, common cold, hepatitis, AIDS

Question 17

How do viruses reproduce?

Answer 17

The virus uses/hijacks the host cell to replicate. The DNA is injected into the host and the host
makes copies of the viral DNA. Also, viruses can mutate and change the shape of their antigens.

Question 18

Describe a fungus.

Answer 18

Any of a group of spore-producing organisms feeding on organic matter, including moulds, yeast,
mushrooms, and toadstools.

Question 19

Name 2 fungal diseases.

Answer 19

Thrush, athletes foot, ringworm.

Question 20

How do fungi reproduce?

Answer 20

Fungi reproduce asexually by fragmentation, budding, or by producing spores.

Question 21

What is the difference between an antiseptic and disinfectant?

Answer 21

Both Kill microorganisms. An antiseptic is applied to the body, while disinfectants are applied to
nonliving surfaces, such as countertops and handrails.

Question 22

How can bacterial infection spread?

Answer 22

Binary fission- in the correct conditions they will divide asexually every 20 minutes

Question 23

Name 4 parts of the first line of defense

Answer 23

hair, cilia, mucous, intact skin, stomach acid, tears

Question 24

Name 2 physical and 2 chemical barriers to disease (first line of defence).

Answer 24

Physical include: hair, cilia, mucous, intact skin
Chemical: stomach acid, lysosomes in tears, sweat.

Question 25

What is a phagocyte?

Answer 25

A type of white blood cell which engulfs pathogens.

Question 26

Why does swelling and redness often occur after infection?

Answer 26

Certain immune cells release HISTAMINE, a chemical that causes an INCREASE of blood flow to the area where pathogens have been detected. White blood cells then come in and consume pathogens (Phagocytosis) This leads to the site becoming Red, swollen, hot and painful. Known as inflammation.

Question 27

Why is it good for scabs to form over cuts?

Answer 27

To seal the skin barrier and prevent further infection

Question 28

What are antigens?

Answer 28

Antigens are proteins located on the surface of our cells and other pathogens. They help the body to determine what is self and non self.

Question 29

What cells produce antibodies?

Answer 29

Lymphocytes- B cells produce antibodies.

Question 30

Where are B and T lymphocytes (white blood cells) produced?

Answer 30

B cells – bone marrow T cells – thymus

Question 31

What are memory white blood cells and what are their function in immunity?

Answer 31

After B cells produce antibodies, some B cells are stored are memory cells. This is stored in the body for a quicker and larger response if the body is encountered with the same pathogen later.

Question 32

What is the difference between active and passive immunity?

Answer 32

Active – the body’s natural defence against the pathogen. Eg. Producing antibodies. Passive – the body is induced eg. Antiviral , vaccinations

Question 33

What are vaccines and how do they work?

Answer 33

Vaccines contain a weakened form of the pathogen. This introduces the body to the pathogen so then the body can build immunity. The body can make B cells and T cells specific to the introduced pathogen to then make memory cells so when the body encounters the pathogen, the body is able to respond faster.

Question 34

Why is it necessary to often have 2 injections against a specific disease?

Answer 34

Some diseases require a booster injection. This is because the memory cells may do not live for long and more need to be produced.

Question 35

What hygiene conditions would help decrease the spread of disease?

Answer 35

Wash hands regularly, cover nose and mouth when coughing, use gloves when handling food.

Question 36

What is an STI/STD?

Answer 36

Sexually Transmitted Infection/Disease

Question 37

Name 2 ways these diseases/infections can spread

Answer 37

Sexual intercourse (Vaginal or oral) Passed from mother to baby in Childbirth or pregnancy