Biology quiz one
Terms
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- continental drift
- A change in the position of continents resulting from the incessant slow motion (floating) of the plates of Earth's crust on the underlying molten mantle. It has caused continents to fuse and break apart periodically throughout geologic history.
- gradulization
- The view that evolution proceeds by isolated populations gradually becoming genetically unique as they are adapted by natural selection to their local environments. Darwin's view of the origin of species.
- microevolution
- a change in a population's gene pool over successive generations; evolutionary changes in species over comparably brief periods of time
- analogy
- similarity of structure between two species that are not closely related; attributable to convergent evolution
- balancing selection
- Natural selection that maintains stable frequencies of two or more phenotypic forms in a population (balanced polymorphism)
- sexual selection
- Change in the gene pool due to behavior that causes preferential mating with one or more genotypes.
- Comparative embryology
- The comparison of early stages of development
- blastula
- The hollow ball of cells marking the end stage of cleavage during early embryonic development
- mutation
- A change in the nucleotide sequence of DNA; the ultimate source of genetic diversity.
- xylem
- The tube-shaped, nonliving portion of the vascular system in plants that carries water and minerals from the roots to the rest of the plant
- evolutionary fitness
- The contribution an individual makes to the gene pool of the next generation, relative to the contribution of other members of the population.
- phylogeny
- The evolutionary history of a group of organisms, generally presented as a branching tree structure and assumed to be based on modern methods of investigating taxonomic relationships.
- disruptive
- Selection that favors alleles towards the endpoints of a frequency distribution, but not alleles towards the middle.
- transpiration
- The evaporative loss of water from a plant; typically via the stomata
- angiosperms
- A flowering plant, which forms seeds inside a protective chamber called an ovary
- bacillus
- A prokaryote species where individuals are rod-shaped.
- halophiles
- Organisms that are found in conditions saline (salty) enough that most organisms cannot tolerate them.
- differential reproductive success
- offspring that survive to reproduce themselves (see fitness)
- immigration
- movement of individuals into a population
- directional
- Selection that causes a shift in allele frequency such that one more more alleles become more common over time.
- cork cambium
- A cylinder of meristematic tissue in plants that produces cork cells to replace the epidermis during secondary growth
- modern synthesis
- A comprehensive theory of evolution that incorporates genetics and includes most of Darwin's ideas, focusing on populations as the fundamental units of evolution.
- mycelium
- The entire network of hyphae making up the body of a fungus.
- thermophiles
- Organisms that are found in conditions hot enough that most organisms cannot tolerate them.
- macronutrients
- A chemical substance that an organism must obtain in relatively large amounts. See also micronutrient
- bottle neck effect
- Genetic drift resulting from a drastic reduction in population size.
- sclerenchyma
- A rigid, supportive plant cell type usually lacking protoplasts and possessing thick secondary walls strengthened by lignin at maturity
- archaea
- One of two prokaryotic domains of life (the other being Bacteria), that share a number of biochemical features with eukaryotes but are typically now found in extreme environments.
- stomata
- (Plural=stomata) A pore surrounded by guard cells in the epidermis of a leaf. When stomata are open, CO2 enters a leaf and water and O2 exit. A plant conserves water when stomata are closed.
- emigration
- movement of individuals out of a population
- vascular
- A continuous cylinder of meristematic cells surrounding the xylem and pith that produces secondary xylem and phloem
- parsimony
- In scientific studies, the assumption that the least complicated explanation is probably the correct one.
- cambrian explosion
- Event in the fossil record about 540 million years ago where all larger animal groups (Phyla) appear in a relatively short period of time.
- casparian strip
- A water-impermeable ring of wax around endodermal cells in plants that blocks the passive flow of water and solutes into the stele by way of cell walls
- heterotrophic
- Organisms that are unable to construct their own food from inorganic sources, and therefore must consume other organisms or organic molecules from the outside environment. Function as consumers or decomposers in food chains.
- gene pool
- All the genes (alleles) in a population at a given time
- population genetics
- The study of genetic changes in populations; the science of microevolutionary changes in populations.
- morphological species concept
- a classification system based on observable and measurable phenotypic traits
- mycosis
- The general term for a fungal infection.
- pressure flow mechanism
- An accepted theory that states that sugars and other solutes are transported via phloem along along a gradient of hydrostatic pressure developed osmotically
- root nudules
- Swellings consisting of plant cells that contain nitrogen-fixing bacteria
- genetic drift
- A change in the gene pool of a population due to chance.
- humus
- Decomposing organic material found in topsoil
- lignin
- A chemical (biopolymer, like proteins and DNA) that hardens the cell walls of plants and makes them more difficult to penetrate by water.
- endospores
- Specially produced internal daughter cells of some bacteria. These are dehydrated, inactive metabolically and protected by a thick outer coat in order to survive adverse environmental conditions, but can rehydrate and begin functioning when conditions have improved.
- Comparative anatomy
- The comparison of body structures and how they vary among species
- autotrophic
- Organisms able to make their own food from inorganic sources, and are therefore capable of maintaining themselves without consuming other organisms or organic molecules.
- stochastic
- A process in which the next state of the environment is partially but not fully determined by the previous state; i.e. some random elements intrude on otherwise predictable rules.
- coccus
- A prokaryote species where individuals are round.
- parenchyma
- A relatively unspecialized plant cell type that carries most of the metabolism, synthesizes and stores organic products, and develops into a more differentiated cell type
- fruit
- A mature ovary of a flower that protects dormant seeds and aids in their dispersal
- double fertilization
- A mechanism of fertilization in angiosperms, in which two sperm cells unite with two cells in the embryo sac to form the zygote and endosperm
- mass extinction
- Events where a comparatively large portion of living species (generally ³90%) goes extinct in a short period of time, and is replaced by a different group of dominant species.
- exaptions
- A structure that has evolved in one environmental context and later becomes adapted for a different function in a different environmental context.
- turgor
- The normal distension or rigidity of plant cells, resulting from the pressure exerted from within against cell walls by the cell contents
- prezygotic
- Reproductive barriers that occur before fertilization of an egg (i.e. before the zygote).
- ingestion
- A heterotrophic mode of nutrition in which other organisms or detritus are brought whole or in pieces inside the body for digestion
- basal lamina
- a layer on which epithelium sits and which is secreted by the epithelial cells.
- mycorrhzae
- (Plural=mycorrhizae) A mutualistic association between plant roots and fungi.
- population
- A group of interacting individuals belonging to one species and living in the same geographic area that therefore can potentially interbreed.
- root pressure
- The upward push of water within the stele of vascular plants, caused by active pumping of minerals into the xylem by root cells
- biogeography
- The study of the geographic distribution of species.
- protobionts
- Collections of abiotically created molecules that direct chemical reactions and are often self-sustaining, and are encapsulated within a membrane.
- endoderm
- The innermost of the three primary germ layers in animal embryos; lines the archenteron and gives rise to the liver, pancreas, lungs, and the lining of the digestive tract
- pseudocoelom
- A body cavity that is not completely lined by tissue derived from mesoderm
- dicots
- A subdivision of flowering plants whose members possess two embryonic seed leaves, or cotyledons
- spores
- In plants and algae, a haploid cell that can develop into a multicellular individual without fusing with another cell.
- ribozymes
- RNAs that can also function as enzyme-like catalysts
- homology
- similarity of form among speciees due to common ancestry
- analogous
- similarity of structure between two species that are not closely related; attributable to convergent evolution
- bacteria
- One of two prokaryotic domains of life (the other being Archaea), that have a number of biochemical differences from eukaryotes and are now the dominant prokayotes in many environments.
- metamorphisis
- The resurgence of development in an animal larva that transforms it into a sexually mature adult
- cation exchange
- A process in which positively charged minerals are made available to a plant when hydrogen ions in the soil displace mineral ions from the clay particles
- choanoflagellates
- A colonial protist that likely gave rise to sponges
- key adaptations
- An adaptation that allows a taxon to colonize a new ecological niche and radiate new species, thus defining a larger group.
- fixation
- The assimilation of atmospheric nitrogen by certain prokaryotes into nitrogenous compounds that can be directly used by plants
- cuticle
- In plants, a waxy coating on the surface of stems and leaves that helps retain water. In animals, a tough, nonliving outer layer of skin.
- taxa
- (Plural=taxa): A proper name of a group, such as Phylum Chordata, class Mammalia, or Homo sapiens, in the hierarchy or groups used to classify organisms.
- spirillum
- A prokaryote species where individuals are spiral/corkscrew shaped.
- punctuated equilibrium
- The idea that speciation occurs in spurts followed by long periods of little change.
- homolgous
- similarity of form among speciees due to common ancestry
- apical meristem
- Embryonic plant tissue in the tips of roots and in the buds of shoots that supplies cells for the plant to grow in length
- sympatric speciation
- The formation of a new species as a result of a genetic change that produces a reproductive barrier between the changed population (mutants) and the parent population. No geographic barrier is present.
- micronutrients
- An element that an organism needs in very small amounts and that functions as a component or cofactor of enzymes. See also macronutrient
- pholem
- The portion of the vascular system in plants consisting of living cells arranged into elongated tubes that transport sugar and other organic nutrients throughout the plant
- stomata
- A microscopic pore surrounded by guard cells in the epidermis of leaves and stems that allows gas exchange
- heterokaryote
- A life stage of fungi in which cells have two separate haploid nuclei of different parental lineages that have not yet fused.
- shoots
- The aerial portion of a plant body, consisting of stems, leaves, and flowers
- gastrula
- The two-layered, cup-shaped embryonic stage
- hyphae
- One of many filaments making up the body of a fungus.
- stabilizing
- Selection that maintains generally unchanging allele frequencies over time.
- lateral meristems
- Cylinder-shaped corers of plant tissue that remain embryonic as long as the plant lives, allowing for indeterminate growth
- protostomes
- A member of one of two distinct evolutionary lines of coelomates, consisting of the annelids, mollusks, and arthropods, and characterized by spiral, determinate cleavage, schizocoelous formation of the coelom, and development of the mouth from the blastopore
- radiometric dating
- A method for determining the age of fossils and rocks from the ratio of a radioactive isotope to the nonradioactive isotope(s) of the same element in the sample.
- artificial selection
- The selective breeding of domesticated plants and animals to enhance particular traits.
- manocots
- A subdivision of flowering plants whose members possess one embryonic seed leaf, or cotyledon
- mycorrhizae
- A mutualistic association between plant roots and fungi.
- lichens
- A mutualistic association between a fungus and alga or cyanobacterium.
- allopatric speciation
- The formation of a new species as a result of an ancestral population's becoming isolated by a geographic barrier.
- predation
- An interaction between species in which one species, the predator, eats the other, the prey
- deuterostomes
- One of two distinct evolutionary lines of coelomates, consisting of the echinoderms and chordates and characterized by radial, indeterminate cleavage, enterocoelous formation of the coelom, and development of the anus from the blastopore
- zygote
- The diploid product of the union of haploid gametes in conception; a fertilized egg
- fossil record
- The fossil species that have been found and their ordered array within layers of sedimentary rock, which provides evidence for the time periods in which those species existed.
- paedomorphisis
- The retention of juvenile features in the adult.
- biological species concept
- a species concept defining a species as a population or group thereof whose members potentially interbreed and produce fertile offspring
- roots
- The subterranean portion of a plant body, consisting of root branches and root hairs
- epidermis
- The dermal tissue system in plants
- postzygotic
- Reproductive barriers that stop reproduction after fertilization (i.e. after the zygote forms).
- ectoderm
- The outermost of the three primary germ layers in animal embryos; gives rise to the outer covering and, in some phyla, the nervous system, inner ear, and lens of the eye
- ground tissue
- A system made up of tissues of mostly parenchyma cells that makes up the bulk of a young plant and fills the space between the dermal and vascular tissue systems
- heartwood
- Located in the center portion of a tree trunk, it consists of older layers of secondary xylem
- blastopore
- The opening of the archenteron in the gastrula that develops into the mouth in protostomes and the anus in deuterostomes
- collenchyma
- A flexible plant cell type that occurs in strands or cylinders that support young parts of the plant without restraining growth
- mesoderm
- The middle primary germ layer of an early embryo that develops into the notochord, the lining of the coelom, muscles, skeleton, gonads, kidneys, and most of the circulatory system
- meristems
- Plant tissue consisting of undifferentiating cells that divide and generate new cells and tissues.
- topsoil
- A mixture of particles derived from rock, living organisms, and humus
- vascular tissue
- A system formed by xylem and phloem of a plant, serving as a transport system for water and nutrients, respectively.
- differential reproductive success
- offspring that survive to reproduce themselves (see fitness)
- natural selection
- reproductive success is unequal, and those individuals best meeting demands of the environment have the greatest reproductive success
- gametangia
- (Plural=Gametangia) A reproductive organ that houses and protects the gametes of a plant
- sporangia
- A capsule in fungi and plants in which meiosis occurs and haploid spores develop.
- coelom
- A body cavity completely lined with mesoderm
- founder effects
- Random change in the gene pool that occurs from a small starting colony size for a population.
- gene flow
- The gain or loss of alleles from a population by the movement of individuals into our out of a population.
- food-conducting
- Have thin primary walls and no secondary walls, and they remain alive at maturity. Also known as sieve-tube members
- binomial
- A system in which each element has two parts, for example the Linnean classification system, where each species has a genus name and specific epithet (e.g. Homo sapiens).
- macroevolution
- Evolutionary change on a grand scale, encompassing the origin of new taxonomic groups, evolutionary trends, adaptive radiation and mass extinctions.
- sapwood
- The lighter colored portion of a log that consists of younger secondary xylem that actually conducts water
- parasitism
- A symbiotic relationship in which the symbiont (parasite) benefits at the expense of the host by living either within the host (as an endoparasite) or outside the host (as an ectoparasite)
- water-conducting
- Composed of tracheids and vessel elements, these both have rigid, lignin-containing secondary cell walls