Chapter 5 - Invaders

Question 1

Antibiotic

Answer 1

Naturally produced or synthetic drug. Used to treat infections, that kills bacteria

Question 2

Antibody

Answer 2

A protein produced by the immune system that detects, identifies and neutralises ‘non-self’ agents, such as bacteria and viruses; each antibody recognizes a specific antigen that is unique to its target; also called immunoglobulin’s

Question 3

Antigen

Answer 3

An antigen is any substance that causes your immune system to produce antibodies against it. An antigen may be a foreign substance from the environment, such as chemicals, bacteria, viruses, or pollen. An antigen may also be formed inside the body, as with bacterial toxins or tissue cells.

Question 4

Autoimmune disease

Answer 4

An autoimmune disease is a disease in which the body identifies some self cells as non-self cells and attacks them. (VCAA examiners report 2008). As a result the B and T lymphocytes attack and destroy self- cells as if they were invading pathogens. This kind of attack leads to a number of diseases such as Diabetes mellitus, Rheumatoid arthritis and Multiple sclerosis.

Question 5

Bacteria

Answer 5

A member of a large group of unicellular microorganisms lacking organelles and an organized nucleus, including some that can cause disease.

Question 6

Bacteriophage

Answer 6

A virus that invades a bacterium

Question 7

Binary Fission

Answer 7

Division of a cell into two without mitosis, only in prokaryotes

Question 8

Disease

Answer 8

Any condition that interferes without how an organism functions

Question 9

Non - Infectious Disease

Answer 9

Non communicable diseases

Question 10

Pathenogicity

Answer 10

The disease causing capacity of a pathogen. Not all pathogens cause disease all the time.

Question 11

Virulence

Answer 11

Intensity of effect of disease

Question 12

Incubation period

Answer 12

Period of which a host is infected but not displaying symptoms.

Question 13

Disease Vectors

Answer 13

Disease transferring organisms

Eg.) Ticks, Flea, Mosquito, ect…

Question 14

Viruses

Answer 14

Non- cellular
disease causing
Need host cell to survive and reproduce
antibiotics ineffective

Question 15

DNA Vs RNA Vs Retrovirus

Answer 15

DNA: Double stranded DNA is injected by virus, DNA must be translated and transcripted.
RNA: RNA stand injected, and used to code for viral proteins.
Retrovirus: Inject RNA trand but have reverse transcriptase enzyme which transcribes RNA to DNA.

Question 16

Virus replication

Answer 16

• Virus particle binds to plasma membrane of cell
• Viral DNA/RNA is injected and replicated
• Viruss are assembled within cell
• Cel lyse and virus’s are released

Question 17

Viroids

Answer 17

Non - cellular

short peices of RNA

Question 18

Prions

Answer 18

Non cellular infectious proteins
Do not contain genetic information
Prions exist naturally
When disease causing prions encounter normal prions it converts the normal prion into a disease causing prion.
effects neural tissue, brain function and co-ordination

Question 19

How does bacteria cause disease

Answer 19

• Most bacteria is good
• But some bacteria can damage tissue as they grow and replicate as they produce powerful toxins as metabolic waste.
• large number of bacteria compete for healthy cells for nutrients and oxygen.

Question 20

How bacteria spread

Answer 20

• Spread through direct contact, in food or water, or droplets of air.

Question 21

Fungi and disease

Answer 21

Digestive enzymes of fungi break down organic material and absorb its nutrients.

Question 22

Infectious vs contagious diseases

Answer 22

Strictly, a contagious disease is one transmitted by physical contact, whereas an infectious one is transmitted via microorganisms in the air or water. In practice, there is little or no difference in meaning between contagious and infectious when applied to disease or its spread.

Question 23

Plant Physical barriers

Answer 23

• Waxy Cutile (smooth, water resistant)
• Hair on leaf (especially at stomata)
• Sunken Stoma
• Bark or thick layers of epidermis

Question 24

Plant Chemical barriers

Answer 24

• Shed infected branches or leaves
• Secrete enzymes that destroy or deter pathogens
• Increase cellulose in cell wall to prevent penetration of physical invasion.
• Hypersensitive cell death

Question 25

What is a pathogen

Answer 25

Infectious agent causing disease