Biology B5

Question 1

Communicable Diseases

Answer 1

Caused by pathogens (such as bacteria and viruses), and can be passed on from one person to another. They can be spread by skin-to-skin contact, exchange of fluids etc. Examples include: ebola, the flu,the cold etc.

Question 2

Non-Communicable Diseases

Answer 2

Non-Communicable diseases cannot be passed on from one person to another. Some examples are heart disease, arthritis etc.

Question 3

Modes of infection

Answer 3

There are many ways that these infections can be spread. These include:

• Skin-to-skin contact
• Through air
• Contact of bodily fluids
• Exchange of bodily fluids
• Sexual interactions

Question 4

Pathogens

Answer 4

Microorganisms that cause diseases are called pathogens. They can be bacteria, viruses, protists or fungi.

Question 5

Compare bacteria to viruses

Answer 5

Bacteria:

• Single-celled
• Living organism
• A minority are harmful

Viruses:

• Have a regular shape
• All are harmful
• Smaller than a cell

Question 6

White Blood Cells-Ingesting Microorganisms

Answer 6

White blood cells which ingest microorganisms are called phagocyte. After you cut yourself, and antibodies enter your blood stream, phagocytes move in. They absorb the invading microbe, and form a membrane bound sac called a vesicle around the microbe. The microbe is then digested and its antigens move to the surface of the blood cell?

Question 7

White Blood Cells-Producing Antibodies

Answer 7

Information about the antigen is transferred to B cells via a helper cells. These B cells produce antibodies that are a specific shape to that antigen. However, some B cells store the information as a memory cells. These memory cells prevent you from getting a pathogen twice, for it kills the pathogen before it can multiply.

Question 8

White Blood Cells-Producing Antioxins

Answer 8

Some white blood cells produce antitoxins. These counteract the toxins released by pathogens.

Question 9

Binary fission

Answer 9

Reproduction by simple cell division.

Question 10

Culture Medium

Answer 10

Liquid or gel used to support the growth of microorganisms or other cultures, often containing specific nutrients.

Question 11

Agar gel

Answer 11

Widely used solid (gel) culture medium used for growing microorganisms

Question 12

Vaccines

Answer 12

Dead or inactive pathogenic material used in vaccination to develop immunity to a disease in a healthy person.

Question 13

STD

Answer 13

Transmitted from an infected person to an uninfected person by unprotected sexual contact.

Question 14

Aphids

Answer 14

Insects that penetrate the plant phloem and feed on the dissolved food. They act as vectors that carry pathogenic viruses, bacteria, and fungi into healthy plant tissue.

Question 15

Chlorosis

Answer 15

The yellowing seen on the leaves of plants when they cannot make chlorophyll due to lack of magnesium ions.