Microbiology

Question 1

What is a pathogen?

Answer 1

An organism or entity capable of causing diseases

Question 2

Host definition.

Answer 2

An organism in which infected pathogens live on or in and multiply.

Question 3

What is pathogenicity?

Answer 3

The ability of a pathogen to cause disease in a host by overcoming the host’s defenses.

Question 4

Parasite definition.

Answer 4

An organism which lives in or on another living organism (host) and obtains nutrients and other resources from the host.

Question 5

What is invasiveness?

Answer 5

The ability of pathogens to invade tissues by overcoming the host’s defense mechanisms and multiply for colonizing.

Question 6

What is toxigenicity?

Answer 6

The ability of microbes to produce biochemical substances known as toxins that disrupt the normal functioning of cells.

Question 7

Mineralization definition

Answer 7

The decomposition of plant and animal residue by extracellular enzymes of bacteria and fungi.

Question 8

What are the significances of mineralization?

Answer 8

1. Removes plant and animal debris from the earth, allowing other organisms to live.
2. Recycles minerals found in limited quantities on Earth.

Question 9

What is nitrification?

Answer 9

The process of oxidizing the nitrogen in the ammonium ion to produce nitrate.

Question 10

What is Nitrogen fixation?

Answer 10

The process of conversion of nitrogen gas into ammonia.

Question 11

What are the methods of reproduction of Bacteria?

Answer 11

Binary fission, fragmentation or budding.
Conjugation.

Question 12

What are the methods of reproduction of Cyanobacteria?

Answer 12

Only asexual. Unicellular forms through normal cell division. Colonial forms through fragmentation.

Question 13

How do fungi reproduce?

Answer 13

Asexually by fission or budding. Filamentous fungi reproduce asexually or sexually by producing spores.

Question 14

What are the modes of nutrition of fungi?

Answer 14

Chemoheterotrophs. Can be saprophytic and absorptive heterotrophs. Can be mutualistics or parasites.

Question 15

How do protists reproduce?

Answer 15

Sexually by the production of gametes, asexually by fission.

Question 16

Consequences of using chemical pesticide instead of BCAs

Answer 16

residues will remain in food and environment, residual toxicity can harm non-target insects and resistance to the pesticide can be developed

Question 17

Why do we use dyes to stain slides?

Answer 17

To highlight the entire microbe and to make cellular shapes, cell arrangements and basic structures MORE VISIBLE.

Question 18

The main morphological symmetries in viruses

Answer 18

Icosahedron and helical

Question 19

Main morphological forms in viruses

Answer 19

Helical, icosahedron or polyhedral, complex and enveloped.

Question 20

Explain the helical and icosahedral forms of viruses

Answer 20

Helical - rigid or flexible rods, like Rabies virus
Icosahedral - icosahedral symmetry, like adenoviruses.

Question 21

Explain the complex virus structure

Answer 21

Have more than 1 form of symmetry with additional structures, like Bacteriophages

Question 22

What are enveloped viruses?

Answer 22

Roughly spherical viruses where the capsid is covered by an envelope. like Herpes simplex virus

Question 23

How are microbes killed in moist heat sterilisation?

Answer 23

Through denaturation of proteins due to high temperature and pressure

Question 24

Through what setup is hot air sterilisation done through?

Answer 24

Dry air ovens.