Biology 11 FINAL BOSS

Almost all of the definitions in the McGraw Hill Ryerson biology 11 textbook . Our class skipped over some stuff but this is mostly everything plus some additional ones I added.

Extinct

Describes a species that has completely disappeared from the earth

Adaptation

A structure behaviour, or physiological process that helps an organism survive and reproduce in a particular environment

Mimicry

A structural adaptation in which a harmless species resembles a harmful species in coloration or structure

Variation

Differences between individuals, which may be structural, functional, or physiological

Selective advantage

A genetic advantage that improves an organism’s chance of survival, unusually in a changing environment

Natural selection

The process by which characteristics of a population change over many generations as organisms with heritable traits survive and reproduce, passing their traits to their offspring

Selective pressure

Environmental conditions that select for certain characteristics of individuals and against other characteristics

Fitness

The relative contribution an individual makes to the next generation by producing offspring that will survive long enough to reproduce

Artificial selection

Selective pressure exerted by humans on populations in order to improve or modify particular desirable traits

Biotechnology

The use of technology and organisms to produce useful products

Monoculture

Extensive plantings of the same varieties of a species over a large plot of land

Catastrophism

The idea that catastrophes such as floods, diseases, and droughts periodically destroyed species in a region, allowing for new species to repopulate the area

Uniformitarianism

Charles Lyell’s theory that geological processes operated at the same rates in the past as they do today

Inheritance of acquired characteristics

The idea that characteristics acquired during an organisms lifetime can be passed onto their offspring

Theory of evolution by natural selection

Theory explaining how life has changed, and continues to change

Evolution

The process of genetic change in a population over time

Survival of the fittest

The idea that the fittest organisms leave the most offspring

Descent with modification

Darwin’s theory that natural selection does not demonstrate progress, but merely results from a species ability to survive at a specific time

Fossil record

The remains and traces of past life that are found in sedimentary rock; it reveals the history of life on Earth and the kinds of organisms that were alive in the past

Transitional fossil

A fossil that shows links between two groups of organisms

Vestigial structure

A structure that is a reduced version of a structure that used to be functional in an organisms lifetime can (ex: leg bones in a whale)

Biogeography

The study of the past and present geographical distributions of species populations

Homologous structures

Structures that have similar structure and origin but different function

Analogous structures

Structures of organisms that do not have a common origin but perform the same function

Embryology

The study of early, pre-birth of an organisms development

Gene flow

The net movement of alleles from one population to another due to the migration of individuals

Non random mating

Mating among individuals on the basis of mate selection for a particular phenotype due to inbreeding

Genetic drift

The change in frequencies of alleles due to chance events in a breeding population

Founder effect

A change in a gene pool that occurs when a few individuals start a new isolated population

Bottleneck effect

Changes in gene distribution that result from a rapid decrease in population size

Stabilizing selection

Natural selection that favours intermediate phenotypes and reacts against extreme variants (A normal mouse does better than a fat mouse and a frail mouse)

Directional selection

Natural selection that prefers one extreme of a phenotype (Humans with more endurance last longest)

Disruptive selection

Natural selection that favours the extremes of a range of phenotypes over intermediate phenotypes (Small salmon are good at sneaking for access to females eggs while large salmon are good at fighting for access to females eggs)

Sexual selection

Natural selection for mating based in competition between males for females

Speciation

The formation of new species from existing species

Pre-zygotic isolating mechanism

a barrier that either impedes mating between species or prevents fertilization of the eggs if individuals from different species attempt to mate; also called pre-fertilization barrier

Post zygotic isolating mechanism

a barrier that prevents hybrid zygotes from developing into viable, fertile individuals; also called post-fertilization barrier

sympatric speciation

speciation in which populations within the same geographical areas diverge and become reproductively isolated

allopatric speciation

speciation in which a population is split into two or more isolated groups by a geographical barrier; also called geographical speciation

ecological niche

the ecological role and physical distribution of a species in its environment

adaptive radiation

the diversification of a common ancestral species into a variety of differently adapted species

divergent evolution

a pattern of evolution in which species that were once similar to an ancestral species diverge, or become increasingly distinct

convergent evolution

a pattern of evolution in which similar traits arise because different species have independently adapted to similar environmental conditions

gradualism

a model of evolution that views evolutionary change as slow and steady, before and after a divergence

punctuated equilibrium

a model of evolution that views evolutionary history as long periods of stasis, or equilibrium, that are interrupted by periods of divergence

species

a group of organisms that can interbreed in nature and produce fertile offspring

morphology

the branch of biology that deals with the structure or form of organisms

phylogeny

the evolutionary history of a species

taxonomy

the branch of biology that identifies, names, and classifies species based on natural features

binomial nomenclature

he system of giving a two-word Latin name to each species—the first part is the genus and the second part is the species

genus

taxonomic group of a closely related species

classification

the grouping of organisms based on a set of criteria that helps to organize and indicate evolutionary relationships

hierarchical classification

the method of classifying organisms in which species are arranged in categories from most general to most specific

rank

a level in a classification scheme, such as phylum or order

taxon

a named group of organisms such as phylum Chordata or order Rodentia

ancestor

an organism (or organisms) from which other groups of organisms are descended

anatomy

the branch of biology that deals with structure and form, including internal systems

physiology

the branch of biology dealing with the physical and chemical functions of organisms, including internal processes

phylogenetic tree

a branching diagram used to show the evolutionary relationships among species

structural diversity

a type of biological diversity that is exhibited in the variety of structural forms in living things, from internal cell structure to body morphology

prokaryotic

a smaller, simple type of cell that does not have a membrane-bound nucleus

eukaryotic

a larger, complex type of cell that does have a membrane bound nucleus

dichotomous key

an identification tool consisting of a series of two-part choices that lead the user to a correct identification

autotroph

an organism that captures energy from sunlight (or sometimes non-living substances) to produce its own energy-yielding food

heterotroph

an organism that cannot make its own food and gets its nutrients and energy from consuming other organisms

species diversity

the variety and abundance of species in a given area

genetic diversity

the variety of heritable characteristics (genes) in a population of interbreeding individuals

ecosystem diversity

the variety of ecosystems in the biosphere

gene pool

all the genes of all the individuals in a population

population

a group of individuals of the same species in a specific area at a specific time

resilience

the ability of an ecosystem to remain functional and stable in the presence of disturbances to its parts

virus

a structure that contains strands of DNA or RNA surrounded by a protective protein coat; it cannot live independently outside of cells

capsid

the outer protein layer that surrounds the genetic material of a virus

replication

the fundamental process of all cells, in which the genetic material is copied before the cell reproduces

lytic cycle

the replication process in viruses in which the virus’s genetic material uses the copying machinery of the host cell to make new viruses

lysogenic cycle

the replication process in viruses, in which the viral DNA enters the host cell’s chromosome; it may remain dormant and later activate and instruct the host cell to produce more viruses

prion

an infectious particle that causes damage to nerve cells in the brain, and that appears to consist mostly or entirely of a single protein

bacterium

an individual prokaryotic cell or a single species that is in the domain Bacteria

archaeon

an individual prokaryotic cell or a single species that is in the domain Archaea

coccus

a micro-organism whose overall morphology is spherical or nearly so

bacillus

a micro-organism whose overall morphology is rod-shaped

methanogenesis

a biological (or chemical) process that produces methane as an by-product

extremophile

an organism that lives in habitats characterized by extreme conditions

mesophile

an organism that lives in habitats characterized by moderate conditions

binary fission

the asexual form of reproduction used by most prokaryotes (and some eukaryotic organelles), in which a cell divides into two genetically identical cells (or organelles)

conjugation

a process in which there is a transfer of genetic material involving two cells

endospore

a dormant bacterial cell able to survive for long periods during extreme conditions

Gram stain

a stain that separates bacteria into two major divisions (Gram positive and Gram negative) based on the cell wall’s response to the stain

protist

a eukaryotic organism, usually unicellular, that is not a fungus, plant, or animal

parasite

an organism that benefits by living in or on another organism at the expense of that organism

cilia

a short, hair-like projection that functions in cell movement and particle manipulation

flagellum

a long, hair-like projection extending from the cell membrane that propels the cell using a whip-like motion

red tide

a coastal phenomenon in which dinoflagellates that contain red pigments are so concentrated that the seawater has a distinct red colour

fungus

a stationary, heterotrophic eukaryotic organism whose cell walls contain chitin

hypha

a multicellular, threadlike filament that makes up the basic structural unit of a fungus

mycelium

a complex, net-like mass made of branching hyphae

fruiting body

the spore-producing reproductive structure in fungi

zygospore

a diploid structure that develops after two haploid hyphae of opposite types combine and fuse their nuclei; this structure is characteristic of zygospore fungi that reproduce sexually during unfavourable conditions

ascus

a small finger-like structure in which sac fungi develop spores

basidium

a club-shaped hypha found in members of the Basidiomycotes; they bear spores called basidiospores