Topic 3- Infection and Response

Question 1

What are pathogens?

Answer 1

Microorganisms that can cause disease

Question 2

Are pathogens communicable or non-communicable?

Answer 2

COMMUNICABLE (easily spread)

Question 3

What can be infected by pathogens?

Answer 3

Plants and animals

Question 4

Make the 4 types of pathogens

Answer 4

Bacteria, viruses, protists and fungi

Question 5

Bacteria:

Answer 5

Very small (about 1/100th the size of you body cells) which can produce rapidly inside your body

Question 6

How does bacteria make you feel ill?

Answer 6

Releases toxins that damages your cells and tissues

Question 7

Viruses:

Answer 7

Tiny, 1/100th the size of bacterium

Question 8

What do viruses make you feel ill?

Answer 8

They produce rapidly, they live inside your cell’s and replicate themselves using the cell’s machinery to produce many copies of themselves

The cell will then burst, releasing all the new viruses

The cell damage is what makes you feel ill

Question 9

Protists:

Answer 9

Single-celled Eukaryotes

Question 10

How does protists make you ill?

Answer 10

Some protists are parasites.

parasites live on or inside other organisms and can cause them damage
often transferred to the organism by a vector which doesn’t get the disease itself (e.g an insect like mosquitoes)

Question 11

Fungi:

Answer 11

Single-celled
Others have a body which is made up of hyphae (thread like structures)

Question 12

How does fungi make you feel ill?

Answer 12

These hyphaes can grow and penetrate human skin and surface of plants, causing diseases.
The hyphae can produce spores, which can be spread to other plants and animals

Question 13

Pathogens can be sores on different ways: name the 3 ways

Answer 13

1)Water
2)Air
3)Direct contact

Question 14

How does water help spread pathogens?

Answer 14

Some pathogens can be picked up by drinking or bathing in dirty water

Question 15

Give examples of pathogens spread through water:

Answer 15

E.g cholera is a bacterial infection that’s spread by drinking water contaminated with the diarrhoea of other sufferers

Question 16

How can pathogens spread through air?

Answer 16

Pathogens can be carried in the air and breathed in

Question 17

Give an example of pathogens that are spread via the air

Answer 17

Some airborne pathogens are carried in the air and droplets produced when you cough or sneeze

the influenza virus that causes flu is spread this way

Question 18

How can pathogens be spread from direct contact?

Answer 18

Some pathogens can be picked up by touching contaminated services, including the skin

Question 19

Give an example of pathogen spread through direct contact

Answer 19

E.g athletes foot is a fungus which makes skin itch and flake off. It’s most commonly spread by touching the same things as an infected person.

-Such as shower floors and towels

Question 20

Give examples of viral diseases (3 to name)

Answer 20

1)Measles
2)HIV
3)Tobacco mosaic virus

Question 21

Give an example of a fungal disease: (just name 1)

Answer 21

Rose black spot

Question 22

Disease cause by protists: (name one)

Answer 22

Malaria

Question 23

Name bacterial diseases: (2 to name)

Answer 23

1)Salmonella
2)Gonorrhoea

Question 24

Name 4 ways you can prevent or reduce risk of communicable diseases:

Answer 24

1) Being hygienic
2) Destroying vectors
3) Isolating infected individuals
4) Vaccinations

Question 25

Human defence system-
Name the 4 human defence systems

Answer 25

1)Skin
2) Hair and mucus in your nose trap
3) the trachea and bronchi
4) the stomach (hydrochloric acid)

Question 26

How do monoclonal antibodies treat diseases?

Answer 26

Monoclonal antibodies can target tumour markers in 4 different ways

1) binds Tumor markers Inside the body showing doctors where a tumor is located

2) can be combined with an anti cancer drug so the drug then combines with the specific cancer cells and kills the cancer cells without killing the normal cells near it

3) can trigger the natural immune system so it recognises and kills the tumor cells

4) They can block the chemicals that stimulate the cancer cells to grow and divide

Question 27

How can monoclonal antibodies be used to treat diseases?

Answer 27

1) monoclonal antibodies can mark where diseases in the body is for doctors to see

2) can be combined with a anti-cancer drug so the drug

Question 28

Cons to using monoclonal antiobidies

Answer 28

Because they are done using mice, they can cause some people to have allergic reactions and there are side effects such as fever, vomiting and low blood pressure therefore it is not used as widely as scientists originally thought they might

Question 29

What are the common signs that a plant has a disease? (6)

Answer 29

1) stunted growth
2) abnormal growth e.g lumps
3) spots on leaves
4) malformed stems or leaves
5) patches of decay (rot)
6) discolouration

Question 30

What causes stunted growth in plants?

Answer 30

Lack of nitrates (because they are needed to make proteins and therefore affect growth)

Question 31

What causes plants to suffer from deficiency symptoms?

Answer 31

Lack of mineral ions from the soil

Question 32

What causes a plant to suffer from chlorosis?

Answer 32

Not enough magnesium ions which are needed for making chlorophyll which is need for photosynthesis, which will then cause the plants leaves to turn yellow

Question 33

How can plant diseases be identified?

Answer 33

1) looking at a garden manaual/ website
2) taking the infected plant to a laboratory where scientists can Identify the pathogen
3) using testing kits that identify the pathogen using monoclonal antibodies

Question 34

What are the different types of plant defences?

Answer 34

1) Physical defences
2) Chemical defences
3) Mechanical defences

Question 35

What are physical defences from a plant?

Answer 35

Waxy cuticle (to stop pathogens entering)

Cell walls made from cellulose (physical barrier If they make it past the waxy cuticle)

Lays of dead cells around the stem act as a barrier to stop pathogens entering (like the outer part of bark in trees)

Question 36

What are chemical defences from a plant?

Answer 36

Anti-bacterial chemicals which kill bacteria (e.g which hazel)

Could use poisons which can deter herbivore
(E.g deadly nightshade or foxgloves)

Question 37

What are mechanical defences from a plant?

Answer 37

Thorns or hair which stopp animals touching and eating them

Some plants leaves drop or curl when something touches them this is to prevent themselves from being eaten by knocking insects of themselves and moving away from things

Some plants can cleverly mimic other organisms, e.g. the passion flower has bright yellow spots on its leaves which look like butterfly eggs which stops other butterflies laying the eggs there

Some species of plants in the ‘ice plant family’ in southern Africa look like stones and pebbles. This tricks other organisms into not eating them.