Chapters 1/10/16 Review Flashcards
Prokaryotes
single-celled organisms that lack a nucleus
How do the two groups of prokaryotes differ?
Archaebacteria lack the peptidoglycan of eubacteria and also have different membrane lipids; also, the Dna sequences of key achaebacterial genes are more like those of eukaryotes than those of eubacteria
What factors are used to identify prokaryotes?
Prokaryotes are identified by characteristics such as shape, the chemical nature of their cell walls, the way they move, and the way they obtain energy
What is the importance of bacteria?
Vital to maintiaining the living world; some are producers that capture energy by photosynthesis, others are decomposers - breaking down the nutrients in dead matter and the atmosphere; other bacteria have human uses
Bacilli
Rod-shaped prokaryotes
Cocci
Spherical prokaryotes
Spirilla
Spiral prokaryotes
Chemoheterotrophs
Heterotrophic prokaryotes that take in organic molecules for energy and a supply of carbon
Photoheterotrophs
Heterotrophic prokaryotes that are photosynthetic - use sunlight for energy - but they also need to take in organic compounds as a carbon source
Photoautotrophs
Prokaryotes that use light energy to convert carbon dioxide and water to carbon compounds and oxygen in a process similar to that used by green plants; found where light is plentiful
Chemoautotrophs
Prokaryotes that can perform chemosynthesis; make organic carbon molecules from carbon dioxide; do not require light as a source of energy, instead they use energy directly from chemical reactions involving ammonia, hydrogen sulfide, nitrites, sulfur, or iron; live deep in the darkness of the ocean
Obligate Aerobes
Organisms that require a constant supply of oxygen in order to live
Obligate Anaerobes
Bacteria that do not require oxygen and may be killed by it; must live in the absence of oxygen
Facultative Anaerobes
A group of bacteria that can live with or without oxygen
Binary Fission
A type of asexual reproduction in which an organism replicates its DNA and divides in half, producing two identical daughter cells
Conjugation
A form of sexual reproduction in which paramecia and some prokaryotes exchange genetic information
Endospore
A type of spore formed when a bacterium produces a thick internal wall that encloses its DNA and a portion of its cytoplasm
Nitrogen Fixation
Process of converting nitrogen gas into a form plants can use; allows nitrogen atoms to continually cycle through the biosphere
What is the structure of a virus?
A typical virus is composed of a core of DNA or RNA surrounded by a protein coat
How do viruses cause infection?
In a lytic infection, a virus enters a cell, makes copies of itself, and causes the cell to burst; in a lysogenic infection, a virus integrates its DNA into the DNA of the hose cell, and the viral genetic information replicates along with the host cell’s DNA
Viruses
Particles of nucleic acid, protein, and sometimes lipids; reproduce only by infecting living cells; and they are not alive
Bacteriophages
Viruses that infect bacteria
Lytic Infection
Process in which a virus enters a cell, makes a copy of itself, and causes the cell to burst
Prophage
Viral DNA that is embedded in the host’s DNA
Lysogenic Infection
A host cell makes copies of the virus indefinitely
Retroviruses
Viruses that contain RNA as their genetic information
How do bacteria cause disease?
Bacteria produce disease in one of two general ways; some bacteria damage the cells and tissues of the infected organism directly by breaking down the cells for food, other bacteria release toxins (poisons) that travel throughout the body interfering with the normal activity of the host
Pathogens
Disease-causing agents
How can bacterial growth be controlled?
There are various methods used to control bacterial growth, including sterilization, disinfectants, and food processing
How do viruses cause disease?
Like bacteria, viruses produce disease by disrupting the body’s normal equilibrium
Vaccine
Preparation of weakened or killed pathogens
Antibiotics
Compounds that block the growth and reproduction of bateria
Viroids
Single-stranded RNA molecules that have no surrounding capsids
Prions
Infectious particle made up of protein rather than RNA or DNA
Archaebactera
Domain Archaea, prokaryotic, unicellular, autotroph, harsh environment
Eubacteria
Domain Bacteria, prokaryotic, unicellular, both autotroph and heterotroph, normal environments.
Protista
Eukaryotic, most unicellular, both autotroph and heterotroph, ponds/lakes
Fungi
Eukaryotic, both unicellular and multicellular, heterotroph, wet areas/dead stuff
Plantae
Eukaryotic, multicellular, autotroph, forests, deserts, water
Animalia
Eukaryotic, multicellular, heterotroph, anywhere food is accessible
