12.1 Animal And Plant Pathogens

Question 1

Communicable diseases

Answer 1

Diseases that can be passed from one organism to another, of the same or different species

Question 2

What are communicable diseases caused by?

Answer 2

Pathogens

Question 3

Types of pathogens

Answer 3

Bacteria
Viruses
Fungi
Protocista

Question 4

What are vectors? Eg…

Answer 4

Carry pathogens from one organism to another

Eg - water and insects

Question 5

Bacteria

Answer 5

Prokaryotes

Do not have membrane bound organelles or nucleus

Question 6

How can bacteria be classified?

Answer 6

By their basic shapes

Their cell walls

Question 7

Different shapes of bacteria

Answer 7

Bacilli - rod shaped
Cocci - spherical 
Vibrios - comma shaped 
Spirilla - spiralled 
Spirochaetes - corkscrew

Question 8

Two types of bacterial cell walls

Answer 8

Gram positive

Gram negative

Question 9

Gram positive bacteria

Answer 9

Look purple blue under microscope

High amount of peptidoglycan

Question 10

Gram negative bacteria

Answer 10

Appear red under microscope

Lower amount of peptidoglycan

Question 11

Virus

Answer 11

Non living infectious agents

0.02-0.3μm - very small

Question 12

Basic structure of viruses

Answer 12

Genetic material (DNA or RNA) surrounded by protein

Question 13

How do viruses work?

Answer 13

Invade living cells - where genetic material of viruses integrates into host cell DNA to replicate the virus
Virus reproduce rapidly and evolve by developing adaptations to the host

Question 14

What are bacteriophages?

Answer 14

Viruses that attack bacteria

They take over bacterial cells and use them to replicate - destroying the bacteria at the same time

Question 15

Protocista

Answer 15

Eukaryotic organisms with a variety of feeding methods

Protists that cause disease are parasitic and use animals/people as host organism

Question 16

How do Protocista enter the body?

Answer 16

Need a vector to transfer them to the host

Or enter the body through polluted water

Question 17

Fungi

Answer 17

Eukaryotic organisms (can be uni or multicellular)

Question 18

How do fungi gain energy?

Answer 18

Cannot photosynthesise and digest food extra cellularly before absorbing nutrients
Most fungi are saprophytes - feed on dead or decaying matter
Some are parasitic - feed on living plants and animals

Question 19

Why are fungal diseases bad for plants?

Answer 19

They often affect the leaves of plants, stop photosynthesis and can quickly kill the plant

Question 20

How do fungi reproduce?

Answer 20

They produce many spores that can travel long distances so they can spread rapidly and widely through crops

Question 21

How do viruses attack host tissues?

Answer 21

Viruses take over cell metabolism
Viral genetic material gets into the host cell and is inserted into the host DNA
Virus uses the host cell to make new viruses, which burst out of the cell and spread to infect other cells

Question 22

How do Protocista attack host tissues?

Answer 22

Take over cells and break them open
They do not take over the genetic material
They digest and use the cell contents as they reproduce

Question 23

How do fungi attack host tissues?

Answer 23

Digest living cells and destroy them

The response of the body to the fungus and this causes the symptoms of disease

Question 24

Toxins and effect on host tissues

Answer 24

Break down cell membranes
Damage/inactivate enzymes
Interfere with host cell genetic material