Key Terms

Question 1

Cell

Answer 1

Fundamental unit of life. It is a dynamic entity - constantly undergoing change.

Question 2

Cytoplasmic (cell) membrane

Answer 2

Permeability barrier that separates the inside of the cell from the outside environment.

Question 3

Cytoplasm

Answer 3

Aqueous mixture of macromolecules - proteins, nuclei acids, lipids, polysaccharides - small organic molecules and inorganic ions.

Question 4

Ribosomes

Answer 4

Protein-synthesising structures.

Question 5

Cell wall

Answer 5

Confers structural strength, relatively permeable, and located outside the membrane.

Question 6

Evolution

Answer 6

The process of change over time that results in new varieties and species of organisms.

Question 7

Phylogeny

Answer 7

Evolutionary relationships between organisms - groups reflect genetic similarity and evolutionary relatedness.

Question 8

Last Universal Common Ancestor (LUCA)

Answer 8

Common ancestral cell from which all cells descended.

Question 9

Strain (of bacteria)

Answer 9

Consists of descendants of a single, pure microbial culture.

Question 10

Spontaneous generation

Answer 10

The idea that living organisms can develop from non-living or decomposing matter.

Question 11

Colony (of bacteria)

Answer 11

A mass of cells.

Question 12

Medical microbiology

Answer 12

Studies diseases of humans and animals.

Question 13

Public health microbiology

Answer 13

Studies the control and spread of communicable diseases.

Question 14

Immunology

Answer 14

Studies how the immune system protects a host from pathogens.

Question 15

Microbial ecology

Answer 15

Concerned with the relationship of organisms with their environment.

Question 16

Agricultural microbiology

Answer 16

Concerned with the impact of microorganisms on agriculture e.g. food safety microbiology.

Question 17

Industrial microbiology

Answer 17

Concerned with fermentation, antibiotic production, and the production of cheese, bread, etc.

Question 18

Microbial physiology

Answer 18

Studies metabolic pathways of microorganisms.

Question 19

Molecular biology

Answer 19

Studies the nature of genetic information and how it regulates the development and function of cells and organisms.

Question 20

Refractive index

Answer 20

A measure of how greatly a substance slows the velocity of light.

Question 21

Focal point

Answer 21

The specific point at which light rays are focused.

Question 22

Focal length

Answer 22

Distance between centre of lens and focal point.

Question 23

Magnification

Answer 23

The ability to make an object larger - not the limiting factor in the ability to see small objects as magnification can be increased without limit.

Question 24

Resolution

Answer 24

The ability to distinguish two adjacent objects as separate and distinct - governs the ability to see very small objects as resolution is a function of the physical properties of light.

Question 25

Working distance

Answer 25

Distance between the front surface of lens and surface of cover glass or specimen when it is in sharp focus.

Question 26

Total magnification

Answer 26

Product of the magnifications of the ocular lenses and the objective lenses.

Question 27

Electron microscopy

Answer 27

Use of electrons instead of visible light to image cell and cell structures.

Question 28

Nucleoid

Answer 28

Non-membrane-bound area of the cytoplasm that contains the chromosome in the form of looped coils.

Question 29

Flagellum

Answer 29

External helical filament whose rotary motor propels the cell.

Question 30

Phospholipid

Answer 30

A molecule consisting of glycerol with ester links to two fatty acids and a phosphoryl head group.

Question 31

Sacculus

Answer 31

Bacterial cell wall.

Question 32

Periplasmic space

Answer 32

Lies between plasma membrane and cell wall. It is smaller in gram-positive bacteria.

Question 33

Exoenzymes

Answer 33

Enzymes secreted by gram-positive bacteria.

Question 34

Glycocalyx

Answer 34

Outermost layer in the cell envelope.

Question 35

Monotrichous

Answer 35

One flagellum.

Question 36

Polar flagellum

Answer 36

Flagellum at end of cell.

Question 37

Amphitrichous

Answer 37

One flagellum at each end of cell.

Question 38

Lophotrichous

Answer 38

Cluster of flagella at one or both ends.

Question 39

Peritrichous

Answer 39

Flagella are spread over the entire surface of cell.

Question 40

Chemotaxis

Answer 40

Movement (of bacteria or archaea) toward a chemical attractant such as nutrients, and away from a chemical repellent.

Question 41

Cell cycle

Answer 41

The sequence of events from formation of a new cell through to the next cell division.

Question 42

Origin of replication

Answer 42

Site at which DNA replication begins.

Question 43

Terminus

Answer 43

Site at which DNA replication is terminated. It is located opposite the origin of replication.

Question 44

Replisome

Answer 44

A group of proteins needed for DNA synthesis.

Question 45

Septation

Answer 45

Formation of cross walls between daughter cells.

Question 46

Balanced growth

Answer 46

Cellular constituents are manufactured at constant rates relative to each other.

Question 47

Unbalanced growth

Answer 47

Rates of synthesis of cellular constituents vary relative to each other.

Question 48

Generation (doubling) time

Answer 48

Time required for the population to double in size.