B5- communicable diseases 🦠

Question 1

What are communicable diseases ?

Answer 1

• communicable diseases can be spread from person to person. For example- measles.
• They are spread by pathogens- [e.g- bacteria or viruses]

Question 2

What are non-communicable diseases ?

Answer 2

• non-communicable diseases cannot be spread from person to person. For example- coronary heart disease.

Question 3

What is the difference between communicable diseases 🆚 non-communicable diseases ?

Answer 3

• communicable diseases can be spread from person to person. For example- measles. They are spread by pathogens- [e.g- bacteria or viruses]
• ; non-communicable diseases cannot be spread from person to person. For example- coronary heart disease.

Question 4

What is health ?

Hint: the state

Answer 4

• health is the state of physical and mental well-being.

Question 5

What are some factors that can have a negative affect on a person’s health ?

Answer 5

• ill health can be caused by communicable and non-communicable diseases.
• But ill health, can also be caused by: poor diet, high levels of stress and other life-situations [e.g- working with chemicals]

Question 6

Explain how TB is a disease can interact with other diseases ?

Hint: defective

Answer 6

• diseases can interact with each other because, one disease can increase the risk of a person, contracting another disease.
• For example, TB [tuberculosis] is a communicable lung disease, that can be fatal and in most people, the immune system can fight off TB.
• ; some people’s immune system may be defective because they have HIV and people with a defective immune system, are much more likely to suffer from infectious diseases.

Question 7

How is HPV a disease that can interact with other diseases ?

Answer 7

• Moreover, some diseases can lead to the cause of another. HPV [the human papilloma virus] is extremely common and harmless in most people; in some people, HPV can cause cervical cancer.
• As most cases of cervical cancer, can be caused by HPV, which infects the cells of the cervix.

Question 8

• Fill in the gaps: Some diseases can be triggered by the _______ system. For example, allergies such as _____ or dermatitis.
• In cases like these, the body is infected with a pathogen, which the ______ system fights off; the person is then left with an allergy.

Answer 8

• Some diseases can be triggered by the immune system. For example, allergies such as arthritis or dermatitis.
• In cases like these, the body is infected with a pathogen, which the immune system fights off; the person is then left with an allergy.

Question 9

How can a mental illness be triggered by a physical illness ?

Answer 9

• a mental illness be triggered by a physical illness
• arthritis is a very painful mount condition, and people with arthritis can find it very difficult to move and live a ‘normal’ life.
• and in certain cases, this can actually lead to people feeling isolated or depressed.

Question 10

What are pathogens ?

Answer 10

• pathogens are, microorganisms that cause infectious diseases.

Question 11

What are the four types of pathogens ?

Answer 11

- the four types of pathogens are:

• bacteria
• viruses
• protists
• and fungi

Question 12

How does bacteria us ill ?

Hint: release

Answer 12

• once bacteria is inside the human body, they reproduce very rapidly.
• the bacteria can then release toxins, which are harmful chemicals.
• these toxins then damage tissues and make us feel ill.

Question 13

How are viruses different to bacteria?

Answer 13

• bacteria can reproduce by themselves [using binary fission]; viruses can’t reproduce by themselves.
• Viruses can only reproduce inside a host cell.

Question 14

How do viruses make us ill ? [4]

Answer 14

• viruses first invade the host cell [e.g- a human cell], and the viruses then reproduce inside the host cell.
• Viruses force cells to stop doing their normal job and make copies of the virus instead.
• The new viruses burst out of the cell, killing it, and this is then damaging to cell, since when the viruses leave the cell, it can cause the cell to burst open and die.
• The cell damage is what makes you ill

Question 15

Explain why viruses are always pathogens, but not all bacteria are.

Hint: invade

Answer 15

• As far as we know, all viruses cause disease and are pathogens- microorganisms that cause infectious diseases.
• This is because they have to invade a living cell in order to reproduce.

Question 16

List all the ways how can pathogens be spread [6]

Answer 16

• some pathogens can be spread by water droplets in the air- [e.g- influenza]
• other pathogens can be spread directly in water- [e.g- cholera spread when drinking water, that is polluted by sewage]
• some pathogens can also be spread by direct contact between individuals- [e.g- HIV can be spread, when drug users share infected needles, or sexual contact]
• food- for example, bacteria that causes food poisoning.
• insect vectors- [e.g- mosquitoes]
• and breaks in skin.

Question 17

How can we reduce the spread of pathogens ?

Answer 17

• washing your hands before eating can prevent the spread of pathogens.
• some patients may be isolated in the case of some highly infectious diseases [e.g- ebola]. Isolation prevents the pathogen from spreading to other people.
• vaccination.

Question 18

Explain how pathogens are passed from one organism to another, and use this to suggest ways of preventing the spread.

Answer 18

• other pathogens can be spread directly in water- [e.g- cholera spread when drinking water, that is polluted by sewage]- providing people with clean drinking water, can also reduce the spread of pathogens.
• For example in the UK, drinking water contains chlorine which kills microbes.

Question 19

Explain how pathogens are passed from one organism to another, and use this to suggest ways of preventing the spread.

Hint: 💉

Answer 19

• some pathogens can also be spread by direct contact between individuals- [e.g- HIV can be spread, when drug users share infected needles, or sexual contact]
• reduce direct contact between individuals- using a condom during sexual intercourse, reduces the spread of HIV.

Question 20

Explain how bacteria can grow and reproduce [4]

Answer 20

• Bacterial cells grow rapidly by dividing in two.
• First the cell copies its genetic material.
• Then the cell splits into two, each with its own copy of the genetic material.
• Since Bacterial cells divide at different rates, this means some can reach huge numbers very quickly

Question 21

What is a key feature about viruses ?

Answer 21

• viruses can’t be killed by antibiotics, because they reproduce inside the host cells