Chapter 2 - Vocabulary Flashcards
Alternation of Generations
a life cycle in which diploid individuals produce spores that create haploid individuals; the haploid individuals reproduce sexually, producing sporophyte individuals and completing the cycle.
Antibiotic
a substance that can kill or weaken microorganisms; natural antibiotics are produced by bacteria or fungi, whereas synthetic antibiotics are manufactured.
Bacillus (plural: bacilli)
a rod-shaped bacterial cell.
Bacteriophage
a virus that infects bacteria.
Binary Fission
the division of one parent cell into two genetically identical daughter cells; a form of asexual reproduction.
Capsid
a protein coat that surrounds the DNA or RNA of a virus.
Capsule
an outer layer on some bacteria; provides some protection for the cell.
Coccus (plural: cocci)
a round bacterial cell.
Conjugation
a form of sexual reproduction in which two cells join to exchange genetic information.
Diploid
a cell containing two copies of each chromosome (2n).
Epidemic
a large-scale outbreak of disease; usually confined to a limited geographic region.
Endospore
a dormant structure that forms inside certain bacteria in response to stress; protects the cell’s chromosome from damage.
Endosymbiosis
a relationship in which a single-celled organism lives within the cell(s) of another organism; recent findings suggest this may be very common.
Facultative aerobe
an organism that can live with or without oxygen.
Fermentation
an anaerobic process that releases chemical energy from food.
Gametophyte
a haploid organism that produces haploid sex cells in an alternation of generations life cycle.
Gene Therapy
a method of treating disease in which genes are introduced into cells to replace, supplement, or repair a defective gene.
Haploid
a cell containing half the usual complement of chromosomes (n).
Horizontal Gene Transfer
the transfer of genetic information from one species into a different species.
Inorganic Chemical
a chemical that has an abiotic origin; some simple substances that are produced by organisms are also classified as inorganic.
Lysis
the rupturing of a cell; can occur when newly made viruses are released from a host cell.
Lysogeny
a state of dormancy in which viral DNA may remain within a host cell’s chromosome for many cell cycle generations.
Mutualism
a relationship between two species that live in very close association with each other, whereby each benefits from the association
Obligate Anaerobe
an organism that cannot survive in the presence of oxygen.
Obligate Aerobe
an organism that cannot survive without oxygen.
Organic chemical
in biology, any chemical that contains carbon and is produced by living things; carbon dioxide is an exception - it is produced during respiration but is classified as inorganic.
Pandemic
an epidemic that occurs over a widespread geographic area, often globally.
Pathogen
a disease-causing agent, often a virus or microorganism.
Plasmid
a small loop of DNA often found in prokaryotic cells; usually contains a small number of genes.
Prion
an abnormally shaped infectious protein responsible for some brain diseases of mammals, including humans.
RNA (ribonucleic acid)
a nucleic acid found in all cells and some viruses; usually carries genetic information that provides instructions for synthesizing protein.
Spirillum (plural: spirilli)
a spiral or corkscrew-shaped bacterial cell.
Spore
a haploid reproductive structure; usually a single cell; capable of growing into a new individual.
Sporophyte
a diploid organism that produces haploid spores in an alternation of generations life cycle.
Transduction
a type of gene transfer in which a virus transfers DNA from one bacterium to another.
Transformation
a process in which a bacterial cell takes in and uses pieces of DNA from its environment.
Viroid
a very small infectious piece of RNA responsible for some serious diseases in plants.
Virus
a small infectious particle containing genetic material in the form of DNA or RNA within a protein capsule.
Zygote
a cell produced by the fusion of two gametes.
