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GCSE Biology B1 > Health and pathogens > Flashcards

Flashcards in Health and pathogens Deck (21):
1

Describe a "healthy diet"

One which contains the right balance of different foods and the right amount of energy

2

What are carbohydrates, fats and proteins used for by the body?
Mineral ions and vitamins (in general terms)?

Releasing energy and building cells
Small amounts of healthy functioning of the body

3

What happens if a person's diet is not balanced?

They are malnourished, which may lead to being over- or underweight, and could also lead to deficiency diseases or conditions such as Type 2 diabetes

4

What happens when the energy content of food taken in is less than the amount of energy expended by the body?
How is this level of energy expended increased?

The person loses mass
Exercise

5

Define metabolic rate
How does it vary?

The rate at which all chemical reactions in the cells of the body are carried out
The amount of activity one does, one's proportion of muscle to fat, and inherited factors

6

Give two examples of when inherited factors affect our health

Metabolic rate
Cholesterol level

7

What is the general trend between the activity/amount of exercise and overall health?

Someone who does lots of exercise is healthier than someone who does little

8

Define a pathogen

A microorganism that causes infectious disease

9

How do bacteria and viruses make us feel ill?

They reproduce rapidly inside the body and may produce toxins/poisons that make us feel ill
Viruses damage the cells in which they reproduce

10

Give three ways in which white blood cells help to defend against pathogens

Ingesting pathogens
Producing antibodies, which destroy specific bacteria or viruses
Producing antitoxins, which counteract the toxins released by the pathogens

11

How does immunity to a pathogen come about in the body?

The immune system produces specific antibodies to kill a specific pathogen, then stores them, so that it can react quickly and destroy that pathogen in the future. Sometimes, dead or inactive pathogens can trigger white blood cells to produce antibodies (such as in vaccination).

12

Summarise Semmelweis' findings

He insisted that doctors washed their hands before contacting and examining patients, which greatly reduced the number of deaths from infectious diseases in his hospital. He thus discovered that washing hands prevents the spread of these diseases

13

What are antibiotics used for, and name the first one to be discovered (Alexander Fleming)?

Penicillin
Medicines that help cure bacterial disease by killing certain bacteria within the body. They can NOT kill viral pathogens (viruses), which live and reproduce inside cells.

14

How do we avoid antibiotic resistant strains of bacteria arising?

Specific bacteria should be treated with specific antibiotics to avoid bacteria becoming resistant to antibiotics
Use minimal quantities, only with a serious bacterial infection (not for things like a mild throat infection)
Develop new antibiotics continually

15

How do pathogens (say, MRSA) produce strains that are resistant to an antibiotic (say, methicillin)?
Why is this dangerous?

Mutations produce new strains, some of which happen to be resistant to the antibiotic
Antibiotics kill the original, non-resistant pathogens - resistant ones survive and reproduce, passing on genetic immunity
The resistant pathogens spread rapidly and often are dangerous because there is no effective treatment

16

Why do painkillers and other medicines help with an infectious disease?
Why are they no good by themselves?

They relieve symptoms, making the person feel well
They do not kill the pathogens that are causing the problems

17

What is the MMR vaccine?

A vaccine used to protect children against measles, mumps and rubella

18

When an uncontaminated culture of microorganisms is required for investigating the action of disinfectants and antibiotics, what steps must be taken to prevent contamination?

Petri dishes and culture media sterilised before use
Inoculating loops used to transfer microorganisms to the media sterilised by passing through a flame
The lid of the Petri dish secured with adhesive tape to prevent airborne contamination

19

In school and college laboratories, what maximum temperature are cultures incubated at? Why?
Why are higher temperatures used in industrial conditions?

25ºC, to reduce the likelihood of growth of pathogens that might be harmful for humans (these would be adapted to thrive at about 37ºC)
To produce more rapid growth

20

What are the advantages of vaccination?

Prevents illness in individuals and populations
Vaccination is often cheaper than treating the illness at a developed stage
Chances of getting seriously ill/dying from side effects much lower than the same from getting the illness

21

What are the disadvantages of vaccination?

May cause reactionary side effects
MMR said to cause autism in children, but this has been discounted officially as untrue