SBI3U - Unit 1 - Definitions

Biodiversity

The variety and number of life forms on earth

Taxonomy

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

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

Species

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

Morphological Species Concept

The comparison of measurements and descriptions of organisms, accounting for variation, to determine if they belong to the same species

Morphology

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

Biological Species Concept

The ability of organisms to interbreed and produce viable, fertile offspring

Phylogenetic Species Concept

The closeness of organisms, as shown by branches in evolutionary relationships

Phylogeny

The evolutionary history of a species

Dichotomous Key

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

Ancestor

An organism from which other groups of organisms descended

Anatomical Evidence

The comparison of the form of species to determine how they are related through evolution

Anatomy

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

Physiological Evidence

The comparison of proteins among species to determine the degree of genetic similarity

Physiology

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

DNA Evidence

The comparison of nucleotides of specific genes to determine the relatedness of organisms

Phylogenetic Tree

A branching diagram used to show the evolutionary relationships among species

Clade

A taxonomic group that includes a single common ancestor and all its descendants

Primitive Traits

An inherited trait from a distant ancestor

Derived Trait

A recently appeared trait in the most recent ancestor forming a new branch

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

Autotroph

An organism that captures energy from sunlight or 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

Unicellular

An organism made of only one cell

Multicellular

An organism made of more than one cell

Prokaryotic Cell

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

Eukaryotic Cell

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

Hypertonic Solution

There is a greater concentration outside of the cell, so water moves out and the cell shrinks

Isotonic Solution

There is an equal concentration inside and outside of the cell

Hypotonic Solution

There is a greater concentration inside of the cell, so water moves in and the cell grows

Bacteria

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

Diplo-

The prefix used for bacteria that aggregate in pairs

Strepto-

The prefix used for bacteria that aggregate in chains

Staphylo-

The prefix used for bacteria that aggregate in clusters

Coccus

A micro-organism whose overall morphology is spherical

Bacillus

A micro-organism whose overall morphology is rod-shaped

Spirillum

A micro-organism whose overall morphology is spiral-shaped

Autotrophic Bacteria

Bacteria that produce their own food

Photosynthetic Bacteria

Bacteria that use chemical energy to convert CO2 and water into carbohydrates

Chemosynthetic Bacteria

Bacteria that use chemical energy from inorganic molecules, such as hydrogen sulfide, to produce organic compounds

Heterotrophic Bacteria

Bacteria that consume other organisms for energy

Saprophytic Bacteria

Decomposers that feed on dead organic matter and act as agents of decay

Parasitic Bacteria

Bacteria that obtain food from living cells and fully depend on the host cells for nutrition

Aerobic Respiration

Oxygen is required to break down organic matter and produce energy

Obligate Aerobe

Bacteria that need oxygen and cannot survive without it

Anaerobic Respiration

Energy is produced by breaking down organic matter in the absence of oxygen

Obligate Anaerobes

Bacteria that cannot grow in the presence of oxygen

Facultative Bacteria

Bacteria that live in either anaerobic or aerobic conditions

Mesophile

An organism that lives in habitats characterized by moderate conditions

Binary Fission

The asexual form of reproduction used by most prokaryotes, in which a cell divides into two genetically identical cells of organelles

Conjugation

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

Transformation

The transmission of genetic material where a DNA segment is picked up by a living bacteria, which can now perform the function of the DNA

Transduction

The transmission of genetic material when a virus infects one cell, and then another, which received the new DNA

Plasmid

A small loop of DNA that is separate from the main chromosome, and contains different genes from the chromosome

Endospore

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

Gram Stain

A stain that separates bacteria into Gram positive and Gram negative, based on the cell wall's response to the stain

Archaea

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

Methanogenesis

A biological or chemical anaerobic process that produces methane as a by-product, unique to Archaea

Extremophiles

An organism that lives in habitats characterized by extreme conditions

Thermophile

A species that can survive extreme heat conditions, such as hot springs

Acidophile

A species that can survive extremely acidic environments, such as volcano craters

Halophile

A species that can survive extremely salty environments, such as the Dead Sea

Protist

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

Endosymbiosis

One prokaryotic cell engulfs a different type of prokaryotic cell forming a symbiotic relationship and functioning like one cell

Parasite

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

Pseudopod

A temporary cytoplasmic extension that amoebas use for feeding and movement

Cilia

A short, hair-like projection that functions in cell movement and particle manipulation when coordinated with other cilia

Flagella

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

Algae

A unicellular or multicellular photosynthetic, aquatic protist

Red Tide

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

Plant

A multicellular photosynthetic eukaryote with cellulose-based cell walls

Embryo

An organism's early pre-birth stage of development

Photosynthesis

6CO2 + 6H2O + Sunlight → 6O2 + C6H12O6

Fungi

A stationary, heterotrophic eukaryotic organism whose cell walls contain chitin

Hypha

A multicellular, thread-like 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

Parasitic Fungi

Fungi that absorb nutrients from the living cells of a host organism, often living inside of it

Predatory Fungi

Soil fungi whose mycelia have special structures for trapping prey

Mutualistic Fungi

Fungi with partnerships with other organism, often plants or protists, where mycelia covers the roots of a plant

Saprobial Fungi

An organism that feeds on dead organisms or organic wastes, which decomposes dead or decaying matter, where it can absorb nutrients and recycle them into the ecosystem

Zygospore

A diploid structure that develops after two haploid hyphae of opposite types combine and fuse their nuclei

Asci

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

Animal

A eukaryotic, heterotrophic, multicellular organism

Diploid

An organism with two sets of chromosomes

Cellular Respiration

6O2 + C6H12O6+ Usable Energy → 6CO2 + 6H2O

Invertebrate

An animal that does not have a backbone

Vertebra

An animal with an internal skeleton and a backbone

Ectoderm

The outer layer of cells

Mesoderm

The middle layer of cells

Endoderm

The inner layer of cells

Asymmetrical

A body plan with an irregular shape

Radial Symmetry

A body plan that can be divided along any plane, through a central axis, into roughly equal halves

Bilateral Symmetry

A body plan that can be divided along one plane, through the central axis, into equal halves

Coelom

A fluid-filled body cavity that provides space for the development of organs

Segmentation

The division of multicellular bodies into a series of repetitive parts

Polyp

The tube-shaped sessile body form of cnidarians