microbiology chapter 1 study

Viruses are not microorganisms because they are not

Composed of cells

Which defines spontaneous generation?

Life arose from non-living matter

Developing a testable hypothesis and defining the specific methods to be used to test the hypothesis is the next step after _______.

Collecting data for a research idea

The highest level in biological classification

Domain

There are three domains:

Bacteria, Archaea, and Eukarya

organisms composed of one or more eukaryotic cells

Eukaryote

Cell type characterized by a membrane bound nucleus

Eukaryotic Cell

Organisms to small to be seen with the naked eye

Microorganisms

A process of formulating a testable explanation for a question, doing controlled experiments to test that explanation, and then publishing the methods, results, and conclusions

Scientific method

A testable explanation of an observation

Hypothesis

Component of a scientific experiment that helps rule out alternative explanations of the results

Control

In science, an explanation supported by an extensive amount of experimental evidence

Theory

The community of microorganisms, as well as their genetic information, in a given environment

Microbiome

Disease causing microbe

Pathogen

Single celled organism that does not contain a membrane bound nucleus

Prokaryote

Cell type characterized by the lack of membrane bound nucleus

Prokaryotic cell

Heterotrophic eukaryotic organisms containing chitin in the cell wall

Fungi

Eukaryotic photosynthetic organisms with relatively simple reproductive structures and no organized vascular system.

Algae

Heterotrophic unicellular eukaryotic organisms that are not fungi.

Protozoa

A cell infected with or capable of being infected with a microorganism or virus; in immunology, one of the body’s own cells (also referred to as self cells).

Host cell

An infectious agent of plants that consists only of RNA

Viroid

An infectious protein that causes a neurodegenerative disease.

Prion

Organisms not composed of cells

Acellular

The scientific name of an organism includes its

Genus and species

Viruses and bacteria are both unicellular

False

an organism that consists of a single cell

Unicellular

All living organisms

May be classified in 3 domains

Archaea are very similar to bacteria and have rigid cell walls made of peptidoglycan

False

Bacteria and eukarya both contain membrane-bound organelles

False

Which if the following is true regarding viruses?

They are obligate intracellular parasites

The cell types that lack a membrane-bound nucleus and have rigid cell walls of peptidoglycan are

Bacteria

The prokaryotic domain includes:

Bacteria and archaea

The eukaryotic domain

Eukarya

The scientist usually credited with seeing the first microorganisms, which he called "animalcules", was

Van Leeuwenhoek

They are only composed of protein

Prions

Bioremediation refers to

using bacteria to clean up environmental pollutants.

The components of fats are fatty acids and

glycerol

The basic subunits of DNA

Nucleotides

Phospholipids are polar molecules

True

Which of the following best describes the structure of DNA

consisting of antiparallel two sugar-phosphate backbones with nucleobases oriented towards the interior

Which of the following are found in RNA but not in DNA?

Ribose AND uracil

Alpha helices and beta-pleated sheets form a protein's

secondary structure

The subunits (building blocks) of proteins are

Amino acids

The Gram stain and the endospore stain both use

safranin

The macromolecule found in the cell walls of all bacteria is

peptidoglycan

The two magnifying lenses found in a light microscope are the

ocular and objective.

Penicillin would be most effective against

actively growing bacteria AND Gram-positive bacteria

The resolving power of a microscope is described as the ability of the microscope to

separate clearly two objects that are very close together.

Extrachromasomal DNA is found in

mitochondria AND plasmids

Which of the following stains are considered differential

Acid-fast stain AND Gram stain.

The cell wall of Gram-positive bacteria

contains a thick layer of peptidoglycan

Select the CORRECT statement regarding basic dyes.

They have a positive charge.

Which of the following is most abundant in bacterial cells

Water

In viewing a microscopic specimen, oil is used to

decrease the refraction AND increase the resolution.

Select the false statement regarding capsules

Capsules take up stains well.

LPS is found in the outer membrane of Gram-negative bacteria

True

Which statements are true for the acid-fast stain

It is useful for distinguishing a small group of organisms, including MycobacteriumAND it uses carbolfuchsin and methylene blue.

Electron microscopes differ from light microscopes in that

magnification is higher

The endospore stain

is applicable to only a few groups of bacteria.

The major criterion used in placing bacteria into different groups is based on differences in

cell wall structure

You discover a new pathogen which you visualize using a light microscope. A negative stain reveals a clear halo around the cells. This suggests to you that the organism

has a capsule

Movement in bacteria

is by means of flagella AND may be referred to as run and tumble

Which is/are TRUE regarding the cell wall of bacteria?

• It determines the shape of the bacteria.

• It prevents the bacteria from bursting.

• It contains peptidoglycan.

• It may be targeted by antimicrobials.

Endospores are

a dormant cell type.

The structures used for motility in both eukaryotes and prokaryotes are

flagella

Which terms refer to bacterial morphology?

Coccus AND Bacillus

The cell wall of Gram-negative organisms

has a thin peptidoglycan layer AND is characterized by an outer membrane containing LPS.

During which phase of the bacterial growth curve does the total number of viable cells decline

Death

The optimum pH for growth of most species of bacteria is

pH 7

The lag phase of the bacterial growth curve is characterized by

metabolically active cells

In the growth curve of a bacteria population, the bacteria are rapidly increasing in number in the

exponential (log) phase.

The solidifying agent used most successfully in bacterial nutrient media is

agar

Organisms that require gaseous oxygen for metabolism are referred to as

obligate aerobes.

In nature, bacteria

may adhere to surfaces by means of pili and slime layers.

Organisms that use organic molecules as their source of carbon are called

heterotrophs