ACTIVITY 2 THE PROKARYOTES

Archaea and Bacteria

The prokaryotes include organisms in one of two domains: _____________ and ______________.

• morphology

• chemical

• nutritional

• biochemical; energy

The prokaryotes are a highly diverse group. They are differentiated by many factors, including

• ___________ (cell shape),

• ___________ composition,

• ___________ requirements,

• _____________ activities and _________ source (sunlight or chemicals).

• Bacillus cereus; Escherichia coli

• Micrococcus luteus; Serratia marcescens

MATERIALS

1. Photos of the following bacterial cultures in agar plate and agar slope:

   • ______________; ______________

   • ______________; ______________

• Bacillus cereus; Staphylococcus aureus

MATERIALS

2. Photomicrographs of the following bacterial cultures:

   • ______________; ______________

colony

A ___________ is defined as a visible mass of microorganisms all originating from a single cell

• colony color or pigmentation

• form

• elevation

• margin

Characters used to accurately describe the morphology of a bacterial colony include

• ___________ or ______________,

• ______,

• ___________ and

• _________.

color (pigmentation)

Agar plate cultures

__________ - bacteria may produce intracellular pigment responsible for the color of the colonies on the agar surface or water-soluble pigment that diffuse into the surrounding medium.

• Most microorganisms are non-chromogenic and colonies appear cream, white or gray.

• margin

• elevation

• form

Agar plate cultures

• ________ - shape of the edge of the colony

• ________ - cross sectional shape of the colony

• ________ - shape of the colony

filiform

Agar slant cultures

__________ - uniform growth along line of inoculation

echinulate

Agar slant cultures

____________ - margins of growth have a toothed appearance

beaded

Agar slant cultures

____________ - separate or semi-confluent colonies

effuse

Agar slant cultures

___________ - growth is thin, veil-like, unusually spreading

arborescent

Agar slant cultures

_______________ - branched, tree-like growth

rhizoid

Agar slant cultures

____________ - root-like appearance