Table of Contents


Binomial Nomenclature: Classification system in which each organism is given a two part scientific name

Class: a group of closely related orders

Eukaryotic Cell: a cell that contains a nucleus

Family: A group of closely related classes

Genus: A group of closely related species

Homologous Structure: Parts of different of different organisms, often quite different, that developed from the same ancestral body part

Kingdom: A group of closely related phylum

Order: A group of closely related families

Phylum: A group of closely related classes

Prokaryotic Cell: A single celled organism whose cells do not have a nucleus

Species: A group of organisms that share similar characteristics and can interbreed with one another to produce fertile offspring

Sub-Phylum: A subdivision of a phylum of organisms. A subphylum contains one or more classes.

Taxonomy: The science of naming organisms and assigning them to groups


Complementary Base Pairing: a pair of bases in which the identity of one base defines the identity of its partner base. E.g.: In a DNA molecule there are two complementary base pairs--Adenine and thymine, and guanine and cytosine.

Convergent Evolution: Phenomenon in which adaptive radiations among different organisms produce species that are similar in appearance and behaviour

Divergent Evolution: Pattern of evolution, also known as adaptive radiation, in which one species gives rise to many species that appear different externally but are similar internally

Deoxyribonucleic Acid (DNA) : Nucleic acid that stores and transmits genetic information from one generation of an organism to the next by coding for the production of a cell’s proteins

Double Helix: The shape of DNA, consist of two strands of DNA that are wrapped around each other in a spiral fashion

Evolutionary Change: Changes in an organism that occur over time and result in the organism being better suited to its environment

Genetic Drift: Random change in the frequency of a gene

Gradual Change Model: Theory that evolutionary change occurs slowly and gradually

Mutation: A change in the genetic material of a cell

Natural Selection: Process in nature that results in the most fit organisms producing offspring

Non-Random Mating: Organisms do not mate randomly, they are looking for specific traits that will increase the chances of survival for their young

Punctuated Equilibrium Model: A theory of evolution that believes that there has been a pattern of long stable periods interrupted briefly by periods of change

Speciation: The creation of new species that is the result of a previously existing species adapting to its environment


Virus: A non-cellular particle made up of genetic material and protein that can invade living cells

Antibody: A special protein that can bind to an antigen on the surface of a pathogen and help to destroy it

Antigen: A foreign substance that induces an immune response and interacts with specific antibodies

Host Cell: A cell that a virus inserts its nucleic acid into for the purposes of replication

Lymphocyte: White blood cell that responds to the presence of antigens

Lysogenic Cycle: Process in which viral DNA is inserted into the DNA of a host cell where it can remain for many generations before becoming active

Lytic Cylce: Process in which a host cell is invaded, used to replicate viral DNA, lysed and destroyed

Nucleic Acid Core: DNA or RNA that is found in the capsid of a virus

Phagocytic White Blood Cell: A white blood cell that engulfs and destroys micro-organisms

Primary Line of Defense: Physical and chemical defenses that prevent foreign invaders from entering the body

Protein Capsid: The protein coat that surrounds the nucleic acid of a virus

RNA: Nucleic acid made of a single strand of nucleotides that acts as a messenger between DNA and the ribosomes and carries out the process by which proteins are made from amino acids

Secondary Line of Defense: A nonspecific immune response that attacks foreign invaders, includes phagocytes, natural killer cells, and developing a fever

Tertiary Line of Defense: A specific immune response, antibodies are created that seek out and destroy specific invaders

Viral Specificity: Viruses will only bind with specific cells; this is determined by the compatibility of proteins on the surface of the virus and on the surface of the host cell

White Blood Cell: Blood cell made in the bone marrow that protects the body against invasion by foreign cells or substances


Chlorophyll: Main pigment involved in photosynthesis

Accessory Pigments: Compounds that absorb light and assist in photosynthesis

Bryophytes: Phylum of plants that is able to survive without being submerged but must have a constant supply of water.

Rhizoids: Root like structures that anchor plants into the ground

Antheridium: Structure in plants that produce sperm

Archaegonium: Structure in plants that produce an egg

Zygote: The product of a sperm fertilizing an egg

Protonema: Tangled mass of filaments that form when a moss spore germinates

Vascular Tissue: Tissue that specializes in the transport of water and nutrients

Xylem: Vascular Tissue that specializes in the transport of water

Phloem: Vascular tissue that specializes in the transport of nutrients

Tracheids: Cells in xylem that carry water from the roots to the leaves of vascular plants

Cuticle: A waxy covering that helps prevent water loss by evaporation

Veins: Bundles of vascular tissue that run through leaves and stems

Rhizomes: stems of ferns that creep underground

Fronds: Large leaves of ferns

Sporangia: Tiny containers that produce spores

Sori: Clusters of sporangia

Prothallium: Heart shaped gametophyte of ferns

Gametophyte: generation of plants that produce eggs and sperm

Sporophyte: Generation of plants that produce spores

Alternation of Generation: Plants alternate between generations that reproduce asexually and generations that reproduce sexually

Roots: structures in plants that grow below ground and provide water for the rest of the plant as well as stability and anchoring

Stems: Structures in plants that grow above ground and hold the leaves up to the sun

Leaves: Plant organs that capture the sun’s energy for photosynthesis

Pollen Grain: Male gametophyte found in seed producing plants

Pollination: The carrying of pollen to the female gametophyte

Embryo: Tiny plant that grows out of the zygote after fertilization

Seed Coat: Protective coating that surrounds the embryo and provides it with food