2. Viruses And Bacteria

Question 1

How do viruses spread within the body?

Answer 1

Once inside a cell, viruses make thousands of copies of themselves and rupture a cell, thus spreading to other areas of the body.

Question 2

What is the body’s natural response to viruses?

Answer 2

White blood cells in humans attempt to surround and destroy viruses

Question 3

How are viruses spread?

Answer 3

• Close contact between people
• Vectors (other organisms that carry the virus from host to host)
• Contaminated food and drink

Question 4

What are the three main ways in which bacteria cause diseases?

Answer 4

They produce toxins which are poisonous to the surrounding host cells.
Stop the host organism from performing it’s normal activities.
The response of the body to the bacteria is so drastic it causes disease.

Question 5

How do bacteria reproduce?

Answer 5

All bacteria consist of one cell, but bacterial cells have a range of shapes and they can join together. A bacterium reproducing into two cells is called binary fission.

Question 6

What do bacteria require to reproduce?

Answer 6

Nutrients
Water
Suitable temperature and pH
May or may not require oxygen based on how they respire.

Question 7

What are the three shapes of bacteria?

Answer 7

Coccus, cocci - spherical
Bacillus, bacilli - rod shaped
Spirullum, spirila - spiral