LESSON 3

science of classification of living organisms

consists of classification, nomenclature, and identification

arrangement of organisms into taxonomic groups (known as taxa)

taxonomic rank used in the classification of living organisms. It is a group of species that share a set of characteristics and are closely related evolutionarily.

second part of a scientific name used to identify a particular species within a genus.

written in lowercase letters.

The Five-Kingdom System of Classification:

Kingdom Prokaryotae

The Five-Kingdom System of Classification:

Kingdom Protista

The Five-Kingdom System of Classification:

Kingdom Fungi

The Five-Kingdom System of Classification:

Kingdom Plantae

The Five-Kingdom System of Classification:

Kingdom Animalia

_ are not included in the The Five-Kingdom System of Classification because they are acellular.

The Three-Domain System of Classification:

(prokaryotic)

The Three-Domain System of Classification:

(all eukaryotic organisms)

based on differences in the structure of certain ribosomal RNA (rRNA) molecules among organisms

includes viruses, viroids, prions

also called "infectious particles”

Complete virus particles

viruses that cause specific types of cancer

examples: Epstein–Barr virus, human papillomaviruses, and human T-lymphotrophic virus type 1 (HTLV-1).

possess either DNA or RNA

unable to replicate on their own

lack genes & enzymes

depend on the ribosomes, enzymes, and metabolites of the host cell for protein and nucleic acid production

Viruses that infect bacteria

categories of bacteriophages:

always cause what is known as the lytic cycle, which ends with the destruction of the bacterial cell.

also known as lysogenic phages

type of bacteriophage that can either replicate lytically (i.e., immediately killing the host bacterial cell and releasing new virions) or integrate their genome into the host cell's chromosome and become dormant, known as lysogeny.

drugs that are used to treat viral infections.

they interfere with virus-specific enzymes and virus production by disrupting critical phases in viral multiplication or inhibiting synthesis of viral DNA, RNA, or proteins.

_ are not effective against viral infections

virus causes acquired immunodeficiency syndrome (AIDS).

small infectious proteins that cause fatal neurologic diseases in animals and humans

most resistant to disinfectants.

short, naked fragments of single-stranded RNA, which can interfere with the metabolism of plant cells.

round bacteria

may be seen singly or in pairs, chains, clusters, packets of 4, or packets of 8

often referred to as rods; they may be short or long, thick or thin, and pointed or with curved or blunt ends.

occur singly, in pairs, in chains, in long filaments, or branched

Extremely short bacilli

two most common techniques of fixation:

not a standardized technique; excess heat will distort bacterial morphology

two most common techniques of fixation:

a standardized technique; the preferred method

The cell walls of _ have a thick layer of peptidoglycan, making it difficult to remove the crystal violet–iodine complex.

_ have a thin layer of peptidoglycan, making it easier to remove the crystal violet; the cells are subsequently stained with safranin

Organisms with especially demanding nutritional requirements

_ is tested by injecting the organism into mice or cell cultures

_ are able to cause disease because they possess:

1. capsules, pili, or endotoxins

   1. secrete exotoxins & exoenzymes

Methods used to identify bacteria in the lab are going toward looking at the organism's DNA or RNA.

3 bacteria that do not posses all the attributes of typical bacterial cells

they must live within a host cell; they cannot grow on artificial culture media

ex. rickettsias and chlamydias

Rickettsias have _

Chlamydias are _ meaning they prefer to use ATP molecules produced by their host cell

Smallest of the cellular microbes

Lack cell wall (assume many shapes)

can cause atypical pneumonia and genitourinary infections in humans

resistant to drugs that attack cell walls

produce tiny “fried egg”

_ include purple bacteria, green bacteria, and cyanobacteria

all use light energy as an energy source

_ and _ do not produce oxygen

_ bacteria that produces oxygen

photosynthesis that produces oxygen

photosynthesis that does not produce oxygen

“ancient”

live in extreme environments

cell walls do not contain peptidoglycan

photosynthetic, eukaryotic organisms

produce by photosynthesis

arranged in colonies or strands

cell walls contain cellulose

rare genus of algae that cause human infections

produced by dinoflagellates that cause “red tides” and can lead to

non-photosynthetic, eukaryotic organisms

unicellular, free-living, found in soil & water

thickened cell membrane found in protozoa

2 stages of protozoan life cycle:

motile, feeding, dividing stage

2 stages of protozoan life cycle:

nonmotile, dormant, survival stage

“false feet”

used by amebae for movement

used by ciliates for movement

flagellates move by means of_

_ have no visible means of locomotion

study of fungi

polysaccharide found in fungal cell walls

_ are the main mode of vegetative growth in fungi, and are collectively called a mycelium.

_ _ _ are types of reproduction for fungal cells

the hyphae are divided into cells by cross walls or septa

the hyphae do not contain septa

_ are eukaryotic, unicellular organisms that lack

mycelia

Individual yeast cells, also referred _

can be observed only using a microscope

A string of elongated buds (yeasts)

Some yeasts produce thick-walled, spore-like structures called _

_ can be used to differentiate yeast colonies from bacterial colonies.

larger than bacteria and are usually oval-shaped

observed in the process of budding.

infectious diseases of humans and animals that are caused by moulds are called _

_ are fungal infections of the outermost areas of the human bodyhair, nails, and epidermis.

_ are fungal infections of the living layer of the skin, the dermis.

_ are fungal infections of the dermis and underlying tissues

_ are fungal infections of the internal organs of the body

ability to live as either yeasts or molds, depending on growth conditions:

• When grown in vitro at body temperature (37C), dimorphic fungi grow as yeasts and produce yeast colonies

• When grown in vitro at room temperature (25C), dimorphic fungi exist as moulds, producing mould colonies.

Attachment, penetration, biosynthesis, assembly, and release

viral infections in which virus is able to hide from a host’s immune system by entering the cells and remaining dormant