Organisms that cause disease

Question 1

Bacteria

Answer 1

-smaller than eukaryotic cells
-can reproduce rapidly once in the host body
-their presence causes disease by damaging cells or by releasing waste products/toxins that are toxic to the host

Question 2

Viruses

Answer 2

-invade cells and take over the genetic machinery and other organelles of the cell
-host cell eventually bursts, releasing many new viruses which will infect healthy cells

Question 3

Fungi

Answer 3

-common fungal infections where the fungus lives in the skin of an animal and where its hyphae which forms mycelium, grows under the skin’s surface
-fungus can send out specialised reproductive hyphae which grow to the surface of the skin to release its spores
-in plants, fungus often lives in vascular tissue where it can gain nutrients
-hyphae releases extracellular enzymes e.g. cellulases to digest the surrounding tissue which causes decay

Question 4

Protoctista

Answer 4

-these organisms usually cause harm by entering host cells and feeding on the contents as they grow
e.g. the malarial parasite Plasdomium, feeds on haemoglobin in red blood cells

Question 5

Examples of diseases cause by bacteria

Answer 5

tuberculosis
bacterial meningitis
ring rot

Question 6

Examples of diseases caused by fungi

Answer 6

athlete’s foot
ringworm
black sigatoka

Question 7

Examples of diseases caused by protoctista

Answer 7

malaria
Blight

Question 8

Examples of diseases caused by viruses

Answer 8

influenza
TMV
HIV/AIDS

Question 9

tuberculosis

Question 10

bacterial meningitis

Question 11

ring rot (in plants)

Question 12

HIV/AIDS

Question 13

influenza

Question 14

tobacco mosaic virus

Question 15

black sigatoka

Question 16

blight (tomatoes and potatoes)

Question 17

ringworm (cattle)

Question 18

athlete’s foot (humans)

Question 19

malaria