Exam 1 Flashcards
Evolution
Changes in allelic frequencies in a population over time
Miller-Urey experiment
- Experiment designed to prove the origin of life from inorganic compounds
- Miller took methane, ammonia, hydrogen, and water, molecules believed to represent the major components of Earth’s early atmosphere and placed them in a closed system
- He ran continuous electric currents through the system, designed to imitate lightening storms
- At the end of the week, Miller observed 10-15% of the carbon converted into organic compounds, 2% amino acids
Character Displacement
Evolutionary divergence when two similar species inhabit the same environment, but one adapts (behavioral, physical) to reduce their competitive pressures for resources, increasing their chance for survival.
Abiotic Selective Pressures
Nonliving pressures (ex. temperature) in the environment that affect the survival of organisms in a population
Phylogenetic Species Concept
species with a parental pattern of ancestry and descent
Photo & Chemo-autotroph
- an organism that gets energy from the oxidation of inorganic compounds.
- an organism that gets energy from photosynthesis
Decomposer
an organism, like a fungus, that decomposes organic material, usually decaying matter
Intron
a segment of DNA or RNA that does not code for proteins and interrupts the sequence of genes
Transduction
transfer of genetic material from one cell to another using bacteria viruses and does not require direct contact.
Lytic Virus
a virus with a reproductive cycle in which copies of a virus are made within the host cell, which then bursts open, releasing new viruses
Vaccine
biological preparation that improves immunity to a particular disease, often made from weakened or killed forms of the microbe
Conjugation pilus
protein structure that extends from the bacterial cell used used to attach to other cells and facilitate DNA transfer
Coccus
circular shaped bacteria
Pathogen
a bacterium, virus, or other microorganism that can cause disease
Hyphae
the main body of a fungus (singular)
Spore
reproductive structure in fungi, either sexual or asexual
Fruiting body
the main part of the fungus above ground, produces spores
Endosymbiont Theory
theory on how mitochondria and chloroplasts could have been ingested by bacteria and become dependent on one another for survival, resulting in a permanent relationship
Adaptive Radiation
a process in which organisms diversify rapidly into a multitude of new forms, particularly when a change in the environment makes new resources available
Natural Selection
one of the basic mechanisms of evolution based on changes in allelic frequencies, where adaptive and dominant species survive
Species
genus and the specific epithet
Eukaryote
has nucleus and other membrane-bound organelles
Prokaryote
does not possess a nucleus or any other membrane-bound organelles
Photo- and Chemo-hetetroph
- photoheterotrophs use light for energy but cannot use CO2 as its sole carbon source so it must use organic compounds from the environment.
- chemoheterotroph obtain energy by the oxidation of electron donors in their environments
Nitrogen Cycle
circulation of nitrogen in nature, consisting of a cycle of chemical reactions in which nitrogen from the atmosphere is fixed in compounds in soil or water
Exon
a segment of a DNA or RNA molecule that codes for a protein or peptide sequence
Transformation
process where genetic material in the form of “naked” DNA is transferred between microbial cells
Lysogenic Virus
kind of virus where it incorporates its genetic material into the host genome; unlike lytic, doesn’t kill the cell
Bacteriophage
virus that infects and replicates within a bacteria
Alternation of Generations
life cycle in fungi that includes both diploid and haploid multicellular stages, producing both spores and gametes
Gram Stain
technique in lab used to identify certain characteristics in bacteria cell walls, like how thick the cell wall is
Bacillus
rod shaped bacterium
Mycelium
main body of a fungi (plural)
Endospore
an extremely resistant dormant cell structure produced by some bacterial species that will survive even when the cell is destroyed
Ascomycota
fungi phylum ex: yeast
RNA World
RNA molecules are hypothesised to have been the precursors to all current life on Earth due to its self-replicating characteristic
Niche Diversification
principle of ecology that says no two species can occupy exactly the same niche within the environment (and survive)
Biotic Selective Pressures
living pressures (ex. predators) in the environment that affect the survival of organisms in a population
Biological Species Concept
a species, members of populations, that actually or potentially interbreed in nature, not according to appearance
Saprobe
an organism, usually a fungus, that feeds on dead or decaying organic matter
Prion
nonliving disease causing agent made entirely of proteins, no DNA or RNA
Conjugation
in unicellular organisms, a form of sexual reproduction where two cells join in temporary union to transfer genetic material
Prokaryotic Fission
aka binary fission, form of asexual reproduction and cell division used by all prokaryotes to produce 2 cells
Retro Virus
composed of RNA; have an enzyme called reverse transcriptase, gives them the unique ability to transcribe their RNA into DNA after entering a cell; retroviral DNA can then integrate into the chromosomal DNA of the host cell, to be expressed ex: HIV
Plasmid
extrachromosomal organelle in some bacteria that help bacteria spread resistance to antibiotics
Peptidoglycan
found in the cell walls of bacteria, stacked on top of each other and cross-linked for extra support for the cell
Spirillum
spiral shaped bacteria
Dikaryotic
cells with a pair of compatible nuclei, working together
Chitin
found in the cell walls of fungi for structural support
Conidia
sexual, non-motile spores of a fungus
Zygomycota
fungi phylum, ex: bread molds
