Ch 1: The Evolution of Microbiology and Microorganism

Question 1

Define the term:

Microorganism

Study Guide

Answer 1

An organism that is too small to be seen clearly with the naked eye and is often unicellular, or if multicellular, does not exhibit a high degree of differentiation

Question 2

Define the term:

Microbiology

Study Guide

Answer 2

The study of microbes.

Question 3

Define the term:

Prokaryote

Answer 3

A single-celled organism that lacks a nucleus and other membrane-bound organelles (e.g., Bacteria and Archaea).

Question 4

Define the term:

Eukaryotes

Study Guide

Answer 4

Organisms that contain cells that have a membrane-delimited nucleus (e.g., plants, fungi, protists, animals are and members of the domain Eukarya).

Question 5

Define the term:

Bacteria

Answer 5

Single-celled prokaryotes lacking a nucleus, with diverse shapes, metabolisms, and reproductive strategies (i.e., binary fission).

Question 6

Define the term:

Archaea

Study Guide

Answer 6

Single-celled prokaryotes without a nucleus, distinct from bacteria in genetics and membrane composition. They thrive in extreme or diverse environments and play key roles in ecological processes.

Question 7

Define the term:

Eukarya

Consider the domain

Study Guide

Answer 7

Organisms with cells containing a nucleus and membrane-bound organelles. They include protists, fungi, plants, and animals, exhibiting diverse structures and functions.

Question 8

Define the term:

Protists

Study Guide

Answer 8

Unicellular (and sometimes colonial) eukaryotic organisms that lack cellular differentiation into tissues. Many chemoorganotrophic _ are referred to as protozoa; many phototrophic _ are referred to as algae.

Question 9

Define the term:

Fungi

Study Guide

Answer 9

Eukaryotic organisms with cell walls made of chitin. They obtain nutrients through decomposition or symbiosis and include yeasts, molds, and mushrooms.

Question 10

Define the term:

Viruses

Study Guide

Answer 10

An infectious agent having a simple acellular organization with a protein coat and a nucleic acid genome, lacking independent metabolism, and multiplying only within living host cells.

Question 11

Define the term:

Viriod

Consider the composition

Study Guide

Answer 11

An infectious agent that is a single-stranded RNA not associated with any protein; the RNA does not code for any proteins and is not translated.

Question 12

Define the term:

Satellite

Consider the composition

Study Guide

Answer 12

Subviral infectious agents composed of DNA or RNA encapsidated with the aid of an unrelated helper virus.

Question 13

Define the term:

Prion

Consider the composition

Study Guide

Answer 13

An infectious agent consisting only of protein; _ cause a variety of spongiform encephalopathies such as scrapie in sheep.

Question 14

Define the term:

Last Universal Common Ancestor (LUCA)

Study Guide

Answer 14

The hypothetical last universal common ancestor of all current life, believed to be a simple, single-celled organism. It likely possessed basic molecular mechanisms like DNA replication, RNA transcription, and protein synthesis.

Question 15

Describe the concept:

RNA World Hypothesis

Study Guide

Answer 15

The theory that posits that the first self-replicating molecule was RNA and this led to the evolution of the first primitive cell.

Question 16

Define this term:

Phylogeny

Study Guide

Answer 16

The evolutionary development of a species.

Question 17

Define this term:

Small Subunit Ribosomal RNA (SSU rRNA)

Study Guide

Answer 17

A component of the ribosome’s small subunit, essential for protein synthesis in all living cells. It is widely used in phylogenetics to study evolutionary relationships due to its highly conserved sequences.

Question 18

Describe this concept:

Endosymbiotic Hypothesis

Study Guide

Answer 18

The idea that mitochondria, and related organelles (e.g., hydrogenosomes), and chloroplasts arose from bacterial endosymbionts of ancestral eukaryotic cells.

Question 19

Define this term:

Strain

Study Guide

Answer 19

A population of organisms that descends from a single organism or pure culture isolate.

Question 20

Describe this concept:

Koch’s Postulates

Study Guide

Answer 20

A set of rules for proving that a microorganism causes a particular disease