APS 122/ HORT 1001 Week 2 Taxonomy and Seed Germination Terms

Binomial nomenclature

It is the system of naming in which two terms are used to denote a species of living organism, the first one indicating the Genus and the second the Specific Epithet.

Class

It is the taxonomic rank below Division and above Order.

Cotyledonary node

It is a food storage structure used in germination.

Dicotyledon

It is a seed plant that produces an embryo with paired cotyledons, floral organs arranged in cycles of four or five, and leaves with net-like veins.

Division

It is the highest taxonomic category, consisting of one or more related classes, and corresponding approximately to a Phylum in zoological classification.

Emergence

It is germination, when the embryo becomes active and the radicle grows through the seed coat.

Epicotyl

It is the portion of the stem of a seedling or embryo located between the cotyledons and the first true leaves.

Epigeal

It is the type of seedling emergence where cell division in the hypocotyl is initially more active and rapid than cell division in the epicotyl. Cotyledons are brought above the soil surface as the hypocotyl expands.

Family

The taxonomic rank below Order and above Genus.

Genotype

It is the genetic composition of an organism.

Genus

A group of species possessing fundamental traits in common but differing in other lesser characteristics. The taxonomic rank below Family and above Specific Epithet.

Hierarchy

It is a system of grouping where each classification is a subset of a superior grouping, and may contain subordinate categories.

Hypocotyl

It is the embryonic shoot below the cotyledons.

Hypogeal

It is the type of seedling emergence where the cotyledons remain below the surface of the ground.

Nomenclature

It is a formal system of names attached to the taxonomic groupings.

Order

It is the taxonomic rank below Class and above Family.

Phenotype

It is the physical appearance of an organism.

Phylum

It is the taxonomic rank below Kingdom and above Class, used in zoological classification.

Radicle

It is the embryonic root that breaks through the seed coat during germination and develops into the seedling's root system.

Seed

It is a ripened ovule containing a seed covering, food storage, and an embryo.

Seed coat

It is the outer layer of the seed.

Seed germination

It is the activation of metabolic pathways of the embryo leading to the emergence of a new seedling.

Specific epithet

It is the uncapitalized Latin adjective or noun that follows a capitalized Genus name in binomial nomenclature and serves to distinguish a species from others in the same genus, as saccharum in Acer saccharum (sugar maple).

Taxonomy

It is the science of classifying organisms.