Microbiology

Question 1

virus

Answer 1

Any of various simple submicroscopic parasites of plants, animals, and bacteria that often cause disease and that consist essentially of a core of RNA or DNA surrounded by a protein coat. Unable to replicate without a host cell, viruses are typically not considered living organisms. A disease caused by a virus.

Question 2

bacteriophages

Answer 2

A bacteriophage is a type of virus that attacks only bacteria. It uses the bacteria to reproduce itself. Bacteriophages work by injecting their own DNA into bacterial cells. They use the biological machinery of the bacteria to reproduce and many more viruses are created this way.

Question 3

lytic cycle

Answer 3

the process in which a virus overtakes a cell and uses the cellular machinery of it’s host to reproduce. Copies of the virus fill the cell to bursting, killing the cell and releasing viruses to infect more cells.

Question 4

lysogenic cycle

Answer 4

Lysogeny, or the lysogenic cycle, is one of two cycles of viral reproduction (the lytic cycle is the other). Lysogeny is characterized by integration of the bacteriophage nucleic acid into the host bacterium’s genome or formations of a circular replicon in the bacterium’s cytoplasm.

Question 5

prophage/provirus

Answer 5

A provirus is a virus genome that is integrated into the DNA of a host cell. In the case of bacterial viruses (bacteriophages), proviruses are often referred to as prophages.

Question 6

Retrovirus

Answer 6

any of a group of RNA viruses that insert a DNA copy of their genome into the host cell in order to replicate, e.g., HIV.

Question 7

prokaryote

Answer 7

a microscopic single-celled organism that has neither a distinct nucleus with a membrane nor other specialized organelles. Prokaryotes include the bacteria and cyanobacteria.

Question 8

eubacteria

Answer 8

a bacterium of a large group typically having simple cells with rigid cell walls and often flagella for movement. The group comprises the “true” bacteria and cyanobacteria, as distinct from archaebacteria.

Question 9

archaebacteria

Answer 9

microorganisms that are similar to bacteria in size and simplicity of structure but radically different in molecular organization. They are now believed to constitute an ancient intermediate group between the bacteria and eukaryotes.

Question 10

bacilli

Answer 10

a rod-shaped bacterium.

Question 11

coccus

Answer 11

any spherical or roughly spherical bacterium. (circular)

Question 12

spirilla

Answer 12

a bacterium with a rigid spiral structure, found in stagnant water and sometimes causing disease.

Question 13

obligate aerobes

Answer 13

a microorganism that lives and grows in the presence of free oxygen

Question 14

obligate anaerobes

Answer 14

an organism that lives and grows in the absence of molecular oxygen

Question 15

facultative anaerobes

Answer 15

facultative anaerobe a microorganism that can live and grow with or without molecular oxygen

Question 16

binary fission

Answer 16

Binary fission (“division in half”) is a kind of asexual reproduction. It is the most common form of reproduction in prokaryotes and occurs in some single-celled eukaryotes. After replicating its genetic material, the cell divides into two nearly equal sized daughter cells.

Question 17

conjugation

Answer 17

Conjugation is the direct transfer of DNA from one bacterial cell to another bacterial cell. The transferred DNA is a plasmid, a circle of DNA that is distinct from the main bacterial chromosome.

Question 18

endospore

Answer 18

An endospore is a dormant, tough, non-reproductive structure produced by a small number of bacteria from the Firmicute family. The primary function of most endospores is to ensure the survival of a bacterium through periods of environmental stress.

Question 19

nitrogen fixation

Answer 19

the conversion of atmospheric nitrogen into nitrogen compounds by certain bacteria, such as Rhizobium in the root nodules of legumes

Question 20

pathogen

Answer 20

pathogen or infectious agent is a biological agent that causes disease or illness to its host. The term is most often used for agents that disrupt the normal physiology of a multicellular animal or plant. However, pathogens can infect unicellular organisms from all of the biological kingdoms.