Lecture 2

Question 1

types of microorganisms

Answer 1

bacteria, fungi, algae, parasites, viruses

Question 2

non cellular microbes

Answer 2

viruses

Question 3

procaryotes

Answer 3

bacteria

Question 4

another procaryote, not pathogenic

Answer 4

archaea

Question 5

earliest life forms ___ years ago

Answer 5

3.8 billion

Question 6

groupings can be assembled into bacterial _____

Answer 6

taxonomic tree

Question 7

scientific name for bacteria uses

Answer 7

binomial nomenclature

Question 8

bacteria species further divide into ___

Answer 8

strains

Question 9

what is the value of bacterial taxonomy?

Answer 9

consistency, relatedness, medical practice

Question 10

this is sufficient for most routine observation

Answer 10

light microscopy

Question 11

light microscope obtains up to _____x magnification

Answer 11

1000

Question 12

magnification up to 200 000x with this

Answer 12

electron microscopy

Question 13

why stain?

Answer 13

increase contrast/highlight, preserve

Question 14

prob of stain?

Answer 14

kills microbe

Question 15

what to do to have living bacteria observed:

Answer 15

hanging drop (wet mount)

Question 16

prob of wet mount?

Answer 16

poor contrast

Question 17

point of fixing?

Answer 17

kill, stick, bind dye

Question 18

thin layer of bacteria on glass slide called:

Answer 18

smear

Question 19

types of stains

Answer 19

simple (single dye), differential (multi dyes)

Question 20

example of differential stain?

Answer 20

gram stain

Question 21

gram negative is __ colour, positive is ___ colour

Answer 21

pink/red, purple

Question 22

how does gram stain work?

Answer 22

primary purple stain, iodine lets bind better, alcohol remove stain from gram negative only, counterstain with safranin

Question 23

if bacteria identified, lab also test for :

Answer 23

susceptibility

Question 24

another ex. of diff. stain?

Answer 24

acid fast stain

Question 25

what is acid fast stain?

Answer 25

2-dye, harsh decolourize step, if acid fast retain original colour

Question 26

example of acid fast species?

Answer 26

mycobacterium tuberculosis

Question 27

what are special stains?

Answer 27

spore stain, flagella stain

Question 28

why use special stains?

Answer 28

see structures not normally vis. under light micro

Question 29

spre stain needs:

Answer 29

heat (thick cell wall prevent stain from penetrate)

Question 30

why want pure culture?

Answer 30

determine identity, resistance, do studies reliably

Question 31

how get pure?

Answer 31

streak plate

Question 32

principle of streak plate:

Answer 32

solid growth media, one cell multiply form colony

Question 33

how to differentiate species on agar?

Answer 33

colony morphology