Biology 197 First Exam
Terms
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- Abiogenesis
- The concept of life emerging from no life. How life on Earth is presumed to have begun.
- Protobiont
- Systems that pre-dated prokaryotic organisms. Essentially early organic material in a membrane-like structure.
- Cyanobacteria
- The first dominant life form on Earth. Used photosynthesis for survival. Responsible for the oxygen-rich atmosphere we have today.
- Stromatolites
- Huge mats of cyanobacteria.
- Eukaryote
- Any organism whose cell or cells contain a nucleus with DNA within.
- Prokaryote
- An organism without a nucleus. Largely single-celled, and are almost certainly the first organisms on Earth.
- Bacteria
- Unicellular, prokaryotic organisms that dominated the early "living" Earth.
- Archaea
- Single-celled organisms with no nucleus or organelles that make up their own domain along with prokarya and eukarya.
- Endosymbiosis
- A process by which one organism lives within another, the interaction benefiting both organism. The internal organism are passed on as the external organism replicates.
- Precambrian
- The period of time stretching from the formation of the Earth until the Cambrian Period during which an abundance of life was formed.
- Ediacaran Fauna
- Organisms, specifically animals, which lived during the Precambrian Eon. Mostly soft(and flat)-bodied, no skeletons. Primarily Annelids, Cnidarians and possibly some Arthropods.
- Mass Extinction
- An event in which there is widespread death across many species. There are 5 "official" mass extinctions in history.
- Archean
- Eon that occurred after Hadean Eon. Cyanobacteria dominated life on Earth during this period.
- Proterozoic
- Occurred after Archean Eon. Endosymbiosis first "caught on" during this time, though there was still an abundance of cyanobacteria.
- Phanerozoic Eon
- Our current eon. Only one where abundant animal life has existed.
- Paleozoic Era
- First era of the Phanerozoic eon. Subdivided into Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and Permian periods.
- Mesozoic Era
- Second era of the Phanerozoic eon during which many lifeforms radiated. Divided into Triassic, Jurassic and Cretaceous periods.
- Cenozoic Era
- Current era, the beginning of which was marked by the Cretaceous-Tertiary Extinction Event.
- Cambrian Explosion
- Massive growth in diversity and radiation of life occurring in the Cambrian Period.
- Hallucigenia
- Extinct genus of animal that evolved and thrived during the Cambrian Explosion.
- Trilobite
- Well known extinct marine arthropods that thrived during the Cambrian Explosion.
- Alimentary Canal
- The "tube within a tube" that runs through an organism from mouth to anus.
- Burgess Shale
- A shale rock formation in British Columbia that contains millions of years of fossils.
- Hox Genes
- Genes that specify the anterior-posterior axis and the segments of an organism. Developed prior to the Cambrian and is the reason for the widespread growth of animal life.
- Adaptive Radiation
- The evolution of diversely-adapted species that share a common ancestor when exposed to new environments.
- Node
- A split in a "tree of life."
- Heterochrony
- The development of similar structures in different unrelated organisms over (often) very different time spans.
- Principle of Parsimony
- The preference for the least complex explanation for an observation.
- Catastrophism
- The belief that ancient, short-lived events rocked the world (typically in a negative way).
- Uniformitarianism
- Slow, gradual processes shaped the world into what it is today. The dominant theory as of today.
- Natural Selection
- Through one way or another, nature weeding out the less-fit organisms.
- Population
- A group of interbreeding organisms (of the same species) that live in a particular area.
- Genetic Variation
- The relative differences in genetic information. Evolution and natural selection favors genetic variation.
- Relative Fitness
- The extent to which an organism is fit to survive in an environment relative to another.
- Allele Frequency
- The "popularity" of an allele in a group of organisms.
- Positive Selection
- A mechanism of natural selection in which one phenotype is favored.
- Adaptive Evolution
- Evolution driven by a number of adaptations that make the organism more fit to survive and/or reproduce.
- Sexual Selection
- A process by which intraspecific competition for mates favors a particular trait or behavior.
- Balancing Selection
- A number of processes by which multiple alleles are maintained in a population ABOVE THE MUTATION RATE.
- Speciation
- The process by which species are formed.
- Biological Species Concept
- A population or group of populations that can produce fertile offspring, but cannot produce fertile offspring with other species.
- Morphospecies Concept
- Emphasizes physical appearance, assuming that a different physical appearance indicates a different species.
- Phylogenetic Species Concept
- Use modern statistical analysis to compare the genetic codes of several organisms to determine a pattern of shared ancestry.
- Anagenesis
- A widespread number of mutations in an entire population to the point that the population can be considered a new species.
- Cladogenesis
- An evolutionary splitting event where several small branches form a "clade."
- Allopatric Speciation
- Physical division of a gene pool (ex. by a new river)
- Sympatric Speciation
- Division of a gene pool without physical separation.
- Vicariance Event
- When a continuous population is divided by a new physical barrier (eg. a new river).
- Dispersal Event
- An event in which a population splits, and its members migrate from each other.
- Prezygotic Barrier
- Barrier that prevents fertilization (eg. specific sperm receptors)
- Postzygotic Barrier
- Limitation that prevents the further survival/reproduction of a hybrid.
- Osmosis
- Diffusion of water across a selectively permeable membrane.
- Diffusion
- Movement of materials across a semi-permeable membrane.
- Osmotic Pressure
- Pressure on a semi-permeable membrane.
- Active Transport
- Movement of molecules across a semi-permeable membrane. Requires energy.
- Open Circulatory System
- System where fluid (called hemolymph) bathes the organs with nutrients and oxygen. No distinction between blood and interstitial fluid.
- Hemolymph
- Fluid found in open circulatory system that contains blood and interstitial fluid.
- Systolic Pressure
- Blood pressure at maximum level.
- Diastolic Pressure
- Pressure at lowest point in blood pressure.
- Transpiration
- Process similar to evaporation. Loss of water through stoma. Allows for diffusion of carbon dioxide into the plant.
- Xylem
-
Tubes that transport water (and some nutrients) into the plant from the roots.
- Phloem
- Tubes that transport nutrients throughout a plant.
- Sieve Elements
- Tube of living cells that transport nutrients.
- Cohesion
- The way that molecules bind to one another (eg. water molecules binding in xylem)
- Adhesion
- Tendency of dissimilar molecules to be attracted to one another.
- Bulk Flow
- Movement of sugar molecules in a plant from a sugar source to a sugar sink.
- Apoplast
- Free diffusional space between plant cells.
- Symplastic
- The inner side of the plasma membrane in which water (and low-molecular solutes) can freely diffuse between plant cells.
- Plasmodesmada
- Microscopic channels that traverse the cell walls of plant cells.
- Casparian Strip
- A band of [cell wall] material that block the passive flow of materials, such as water and solutes into the Stele of a plant
- Nitrifying Bacteria
- Bacteria that feed on inorganic nitrogen compounds. Feed on ammonia compounds.
- Mycorrhizae
- Fungi that live symbiotically on the roots of plants. Often sold to farmers for healthier plants.
- Epiphytes
- A plant that grows (non-parasitically) on another plant.
- Mutualism
- A relationship between two different species that results in a gain of Darwinian fitness for both organisms.
- Parasitism
- Relationship where one organism lives at the expense of its host.
- Symbiosis
- Close and long-term positive relationships between organisms from two different species.
- Dissociation Curve
- Curve that relates oxygen saturation with the partial pressure of the oxygen in the blood.
- Hemoglobin
- Molecule that is found on red blood cells that binds oxygen and carbon dioxide.
- Hemocyanin
- Copper-based molecule that is found in most mollusks and some arthropods.
- Partial Pressure
- The pressure of a given dissolved gas relative to the makeup of the air.
- Solubility
- The ability of something to be dissolved into a liquid.
- Gills
- Breathing organ in aquatic animals that absorb oxygen and release carbon dioxide.
- Counter-Current Exchange
- Method of transport between two flowing fluids through a semipermeable membrane.
- Nernst Equation
- Calculation that determines the membrane voltage for a particular ion at equilibrium.
- Potential Energy
- Stored energy that can be converted to kinetic energy, thermal energy, sound energy, etc.
- Work
- Energy transferred from a source to something else.
- Volts
- Units of electrostatic potential.
- Joules
- Units used to measure work.
- Ion-Gated Channels
- Channels that respond to electrical stimuli.
- Action Potential
- The electrochemical surge through a nerve cell.
- Hyperpolarization
- The gradient of a nerve cell becoming more and more negative as a part of an action potential.
- Depolarization
- Only sodium enters channel, gradient returns to normal.
- Dopamine
- Neurotransmitter that increases heart rate and blood pressure.
- Serotonin
- Neurotransmitter. Affects muscular system (excitatory).
- GABA
- Neurotransmitter. Affects the CNS (inhibitory).
- Muscle Fiber
- Consists of actin and myosin.
- Neuromuscular Junction
- Junction where a nerve and muscle connect.
- T-Tubule
- Tubule through the sarcolema that facilitates depolarization.
- Sarcoplasmic Reticulum
- Endoplasmic reticulum found in smooth and striated muscle. Stores/pumps calcium ions.
- Sarcomere
- Multi-protein complexes that are composed of filaments.
- Thick Filament
- Myosin filament (part of sarcomere).
- Thin Filament
- Actin filaments (part of sarcomere).
- Cephalization
- Evolutionary process where nervous tissue becomes concentrated on one end of an organism.
- Seta
- Bristles that are extremely sensitive and located on the skin.
- Long-Term Potentiation
- An increase in synaptic transmission strength due to repeated use of that synapse.
- Mechanoreceptors
- A nervous receptor that picks up on pressure.
- Nociceptors
- Sensors that feel pain.
- Transduction
- The transportation of stimuli to the nervous system.
- Sensory Transduction
- The conversion of stimulus energy into a change in membrane potential of a sensory receptor.
- Tympanic Membrane
- Eardrum. Located at the end of the external auditory canal.
- Photoreceptor
- Sensory receptors that pick up light (rods for brightness, cones for color).
- Hormone
- Chemical signal that is transmitted through the bloodstream.
- Endocrine System
- The system that regulates hormone levels in the body.
- Lipid Solubility
- The ability of a lipid to dissolve and be transported across a cell membrane.
- Epinephrine
- Excitatory hormone that is released as part of the "fight or flight" response.
- Arabidopsis
- A genus of small flowering plants that are model organisms for the manipulation of signal transduction pathways.
- Ethylene
- Hormone that has been extensively researched in the study of Arabidopsis.
- Positive Feedback
- Response to a physiological change that increases the initial response.
- Negative Feedback
- Response to a physiological change decreases the initial response.
- Malpighian Tubes
- Mechanism by which insects excrete waste.
- Ultrafiltration
- A variety of membrane filtration in which hydrostatic pressure forces a liquid against a semipermeable membrane.
- Reabsorption
- Re-uptake of water from Malpighian tubes.
- Protonephridia
- Kidney-like organs found in nearly all flatworms.
- Metanephridia
- Kidney-like organs found in annelids, arthropods and mollusks.
- Nephron
- The basic structural and fuctional unit of the kidney.
- Glomerulus
- A tuft of capillaries that functions as the initial stage of excretion.
- Loop of Henle
- Long tube through which water and ions are reabsorbed into the kidneys.
- Antidiuretic Hormone
- Hormone that stimulates the reabsorption of water into the interstitial fluid.
- Immunity
- the ability to resist disease
- Innate immunity
- the kind of defense that is mediated by phagocytic cells antimicrobial proteins, the inflammatory repsonce and natural killer cells. It is present before exposure to pathogens and is effective from the time of birth
- Acquired immunity
- the kind of defense that is mediated by B cells and T cells. it exhibits specificity, memory, and self-nonself recognition
- Cell-mediated immune response
- Immune cells (lymphocytes T) kill directly infected cells
- Humoral immune response
- immune cells (lymphocytes B) release immune agents (antibody) in body fluid that will neutralize pathogens
- Antigens
- molecules recognized by the immune system
- Antibody
- a protein secreted by plasma cells that binds to a particular antigen and marks it for elimination
- Phagocytosis
- a type of endocytosis involving large, particulate substances, accomplished mainly by macrophages, neutrophils and dendritic cells
- thermoregulation
- the maintence of internal body temperature within a tolerable range
- ectotherm
- gain heat from external sources or through internal muscle contractions to warm the body.
- endotherm
- generate heat by metabolism
- climate envelope modeling
- examine shifts in species distributions based on existing distributions and projected distributions given changed climate
- microhabitat
- "The species that have evolved the greatest tolerance to high temperatures have done so at the expense of the acclimation capacity CTmax, and it is these species that will be the most susceptible to the smallest increases in microhabitat temperatures"
- stomata
- a microscopic pore surrounded by gaurd cells in the epidermis of leaves and stems that allows gas exchange between the environment and the interior of the plant
- C4 and CAM plant strategies
- keep CO2 separately to allow plant to close stomata in high temperatures, can sequester CO2 if stomata are closed
- thermal tolerance
- Ability to tolerate temperature change (temperate species were able to acclimate over a greater temperature difference whereas the tropical species had compromised its ability to adapt to temperature change when it evolved adaptions to extreme temperatures)
- Sexual reproduction
- a type of reproduction in which two parents give rise to offspring that have unique combinations of genes inherited from the gametes of the two parents
- Asexual reproduction
- a type of reproduction involving only one parent that produces genetically identical offspring by buddying or by the division of a single cell or the entire organism into two or more parts
- Two-fold cost of sex
- unless the sexual couple produces twice as many offsprings as the asexual individual, there will be a cost of sex, fewer offspring per sexual parent thatn per asexual parent
- Fission
- the separation of a parent into two or more individuals or approximately equal size
- Fragmentation
- a means of asexual reproduction whereby a single parent breaks into parts that regenerate into whole new individuals
- Pathenogenesis
- eggs develop w/out sperm/fertilization, offspring are descendants of mother but not clones (pathogenic - capable of causing disease)
- Conjugation
- in prokaryotes, the direct transfer of DNA between two cells that are temorarily joined. In cilates, a sexual process in which two cells exchange haploid micronuclei
- Transformation
- incorporation of DNA obtained driectly from the environment into the genome. Occurs naturally in some bacteria; can be induced in the lab by certain processes
- Gametes
- a haploid cell such as an egg or sperm. Gametes unite during sexual reproduction to produce a diploid zygote
- Spores
- a single cell produced by mitosis or meiosis that is capable of developing into an adult organism
- Gonads
-
the male and female sex organs the gamete-producing organs in most animals
- density
- the number of individuals per unit area or volume
- dispersion
- the pattern of spacing among individuals within the boundaries of the population
- demographics
- the study of vital statistics of population and how they change over time
- Carrying Capacity
-
the maximum population size the environment can support
- Life tables
- age specific summaries o the survival pattern of a population
- Survivorship curves
- a plot of the number of members of a cohort that are still alive at each age, one way to represent age-specific mortality
- Population regulation
- the control of population size
- Population dynamics
- the study of populations in relation to the environment, including environmental influence variations in population size
- Age structure
- the relative number of individuals of each age in a population
- community
- an assemblage of populations of various species living close enough for potential interaction
- Species diversity
- the variety of organisms that make up the community
- species richness
- the total number of different species in the community
- relative abundance
- the proportion each species represents of the total individuals in the community
- Interspecific interactions
- relationships between species in a community
- competitive exclusion
- local elimination of a competing species
- competitive exclusion principle
- two species competing for the same limiting resources cannot coexist in the same place
- predation
- interaction where one species, the predator, kills and eats the other, the prey
- commensalism
- one species benefits andthe other is apparently unaffected
- herbivory
- an interaction in which an herbivore eats parts of a plant or alga
- Trophic structure
- the feeding hierarchy between organisms in a community
- food chains
- link trophic levels from producers to top carnivores
- Keystone species
- exert strong control on acommunity by their ecological roles or niches
- Fertilization
- union of sperm and egg, sets development in motion
- Cleavage
- a period of rapid cell division without growth
- Blastula
- a ball of cells with a fluid filled cavity
- Bastomeres
- small cells produced in cleavage
- Blastocoel
- the fluid filled cavity in a blastula
- Gastrulation
- cells are rearranged into a three layered gastrula
- gastrula
- three-layered embryo, has primitive gut
- organogenesis
- the specialization of cell function and organization of cells into specific tissues and organs
- blastomeres
-
cleavage partitions the cytoplasm of one large cell into many smaller cells
- polarity
- distribution of stored nutrients in an embryo
- yolk
- the nutrient-rich cytoplasm inside an egg cell, used as food for the growing embryo
- vegetal pole
- the lower half of an amphibian egg cell, containing most of the yolk. this portion eventually becomes part of the gut
- animal pole
- the portion of an egg that is opposite of the vegetal pole and that contains the nucleus and most of the cytoplasm
- cortical rotation
- the orientation of the grey crescent so that it is opposite of the entry point of the sperm, important for spatial orientation and polarity
- grey crescent
- a region of an amphibian zygote that becomes visible shortly after fertilization, opposite that point of sperm entry
- Blastocyst
- and embryonic stage in mamals, a hollow ball of cells produced one week after fertilization in humans
- embryoblast
- inner cell mass of a developing embryo
- blastocyst cavity
- same as blastocoel, the fluid filled cavity
- trophoblast
- an outer layer of cells of the blastocyst, attaches to the wall of the uterus, forming the placenta
- embryo
- a new, developing individual
- amniotic sac
- a membrane filled with amniotic fluid that helps cushion the embryo and keeps it at a constant temperature
- yolk sac
- in an amniotic egg, the membrane-bound sac that contains the yolk
- germ layers
-
the three layers produced by gastrulation
- ectoderm
- the outer layer of an embryonic cell, forms the covering and nervous system
- endoderm
- the inner layer of cells in an embryonic cell, forms the digestive tract and organs
- mesoderm
- partly fills the space between the endoderm and ectoderm in an embryonic cell, forms the muscle, bones, bloods etc.
- Morphogenesis
-
a process of embryologic development during which cells become organized into recognizable tissues, organs, and other structures
- cytoskeleton
- a networkof microtubules microfilaments, and intermediate filaments that branch throughout the cytoplasm and serve a variety of mechanical and transport functions
- induction
- the ability of one group of embryonic cells to influence the development of another
- Monogamous
-
one male mates with one female, they form a pair bond, share task of brood-rearing, similar morphologies
- polygamous
- an individual of one sex mates with several individuals of the other sex
- ploygyny
- one male mates with variable number of females
- polyandry
- a female mates with more than one male
- promiscuity
- both sexes mated with multiple partners
- intersexual selection
-
members of one sex choose mates on the basis of certain traits
- intrasexual selection
- involves competition between members of the same sex for mates
- female choice
- when females choose the males, this provides certain sexual pressures
- Transfer effect
- (Bower birds) The bowers that the birds build are “displaced plumage†instead of Being pretty, they build a pretty house (this term only applies to the bower birds)
- fixed action pattern
- a sequence of unlearned, innate behaviors that is unchangeable
- kinesis
- a simple change in activity or turning rate in response to a stimulus
- taxis
- a more or less automatic oriented movement towards or away from a stimulus
- migration
- a regular long-distance change in location
- Innate behavior
-
developmentally fixed and under strong genetic influences
- learning
- the modification of behavior based on specific experiences
- imprinting
-
a type of rapid irreversible learning in which young animals learn the distinctive appearance of the individual caring for them
- sensitive period
- a limited developmental phase that is the only time when certain behaviors can be learned
- spatial learning
-
a more complex modification of behavior based on experience with the spatial structure of the environment
- landmarks
- a point of reference for orientation during navigation
- ecosystem
- consists of all the organisms living in a community, as will as the abiotice factors with which they interact
- energy flow
- the flow of energy through a food chain (key part is that it comes and goes)
- chemical cycling
- the cycling of chemicals through an ecosystem (key part is that it stays in an area)
- nutrient cycles
- define the connectivity at all levels of biological organization, quantifies the effects of perturbations on multiple levels, assess the paracmeter that limit and promote success of the systems.
- Carbon cycle
-
-carbon is stored in fossil fuels, soils/sediments, solutes in oceans, plant and animalbiomass
taken up by photosynthesis
-released by respiration,
-volcanoes, burning of fossil fuels ***
Greenhouse effect – CO2, water vapor and other greenhouse gases reflect infared radiation back toward the earth (instead of away) and increasing atmospheric CO2 magnify greenhouse effect which causes global warming and climate change - Nitrogen cycle
-
-nitrogen is stored in amino acids, proteins, nucleic acids
taken up when converted into NH4+ or NO3- by nitrogen fixing bacteria so plants can use it
-released when organic nitrogen is decomposed to NH4+ by ammonification and NH4+ is decomposed to NO3- by nitrification,
-denitrification converts NO3- to N2 (rhizosphere, phytoplankton blooms) - Water cycle
-
-water is stored in the ocean (97%), 2% in glaciers and polar ice, 1% is freshwater
evaporation → transpiration → condensation → precipitation → movement through surface and groundwater
acid rain is caused by burning wood and fossil fuels, release sulfur and nitrogen oxides that form sulfuric acid and nitric acid when in contact w/ water (rain) - Phosphorous cycle
-
-stored in nucleic acids, phospholipids and ATP, phosphate is the most important inorganic form of phosphorous, largest reservoirs are sedimentary rocks or marine origin, the oceans, and organisms
-taken up when phosphate binds w/ soil particles, is incorporated into producers and then eaten by consumers
-phosphorous is returned to the soil via excretion and decomposition - biophilia
- the human emotional or psychological connection to nature
- conservation biology
- integrated study at all levels of biology to sustain biodiversity at all levels
- restoration ecology
- use of ecological approaches to recover degraded ecosystems
- biodiversity
- the variety and relative abundance of species present in a certain area. genetic, species, ecosystem
- ecosystem services
- the processes through which natural ecosystems sustain human life
- bioremediation
- use of organisms to detozify environments
- bioaugmentation
- use of organisms to add key materials to an ecosystem
- sustainable development
- meet todays needs without compromising the future generations ability to meet their needs