Three Domains of Life and Microbial Diversity

These flashcards cover key concepts related to the three domains of life, microbial characteristics, and important microbiological processes.

Archaea was discovered in __.

the 1970s

Prokaryotes are not well suited for inferring __ relationships.

deep phylogenetic

The rRNA gene is present in the __ ancestor of all life.

common

Bacteria have __ linked bonds in their membrane lipids.

ester

Peptidoglycan is present in bacteria and absent in __.

archaea and eukarya

Bacteria reproduce asexually through __.

binary fission

Bacteria can exchange genetic information through __, transformation, and __.

conjugation; transduction

Gram positive bacteria retain __ dye and appear blue or purple.

violet

The first known archaea were discovered in __ environments.

extreme

The methanogens are a type of archaea that produce __ gas.

methane

Koch's postulates are used to establish if a microorganism causes a __ disease.

particular

Exotoxins are released by the __ organism and are highly toxic.

living

Bacterial cells that exhibit __ resistance are a significant concern in medicine.

antibiotic

Bacteria can develop resistance to antibiotics through __.

mutation and gene transfer

The __ layer of gram positive bacteria is thick compared to the thinner layer in gram negative bacteria.

peptidoglycan

The common ancestor between the three domains of life existed about __ years ago.

3 billion

Lateral gene transfer among microbes contributes to __ diversity.

genetic

Cyanobacteria are photosynthetic and are the origin of __.

chloroplasts

In some environments, archaea are present in __ abundance.

low

Microbes can communicate through chemical signaling known as __.

quorum sensing

Endotoxins are released when the __ cell wall lyses.

bacterial

The main physical barrier against disease is the __.

skin

The method of amplification of DNA used in laboratories is derived from __ species.

thermophilic