prokaryote diversity

Question 1

why are bacteria and archaea both classified as prokaryotes?

Answer 1

they are both single celled organisms that lack a nucleus

Question 2

differences between prokaryotes and eukaryotes

Answer 2

prokaryotes - smaller, unicellular

eukaryotes - multicellular, contains nucleus

Question 3

differences between bacteria and archaea

Answer 3

archaea - three RNA polymerase, lacks peptidoglycan

Bacteria - one RNA polymerase, peptidoglycan, reacts to antibiotics differently

Question 4

gram positive and gram negative

Answer 4

positive - thick peptidoglycan wall, no outer lipid membrane, purple
negative - outer and inner membrane, thin peptidoglycan wall, pink

Question 5

what is taxis

Answer 5

movement of an organism in repose to a stimulus such as light or the presence of food

anti-clockwise - swimming motion
clockwise- tumble motion

Question 6

describe DNA found in bacteria

Answer 6

contains a singular membrane called the bacterial chromosome. the chromosome, several proteins and RNA molecules form the nuclei which sits in the cytoplasm of the bacterial cell.

Question 7

how do bacteria gain genetic variation?

Answer 7

the three mechanisms of horizontal gene transfer - transformation, transduction, conjugation

Question 8

transformation

Answer 8

process of horizontal gene transfer by which some bacteria take up foreign genetic material from the environment

Question 9

transduction

Answer 9

process by which a virus transfers genetic material from one bacterium to another

Question 10

conjugation

Answer 10

process by which bacterium transfers genetic material to another through direct contact

Question 11

morphologically

Answer 11

how they are formed and their relationship

Question 12

metabolic diversity

Answer 12

different metabolic strategies that organism have evolved to obtain energy

Question 13

obligate aerobes

Answer 13

require O2 for cellular respiration

Question 14

facultative anaerobes

Answer 14

will use O2 if present but can also grow by fermentation in an anaerobic environment

Question 15

obligate anaerobes

Answer 15

poisoned by O2 and use either fermentation or anaerobic respiration

Question 16

extremophiles

Answer 16

bacteria living in extreme conditions such as hot springs, salt lakes or highly acidic environments

Question 17

some ways that prokaryotes are important for the biosphere

Answer 17

recycle nutrients by decomposing dead organisms and allowing their nutrients to be reused, they continuously move carbon through the atmosphere, live in digestive systems of animals

Question 18

endotoxin

Answer 18

toxic substance bound to the Bactria cell wall and released when the bacterium ruptures or disintegrates

Question 19

exotoxin

Answer 19

a soluble poisonous substance produced during the growth of a micro-organism and released into the surrounding medium

Question 20

difference between food poisoning and food infection

Answer 20

food infection - caused by the ingestion of food containing live bacteria which grow and establish themselves
food poisoning - illness caused by food contaminated with bacteria, viruses or parasites