Dry, one-seeded fruit that splits to release the seed

A small, rayless, fleshy dorsal fin present in certain fishes

The process by which a plant releases chemicals that can inhibit or benefit other plant species

Leaves spaced singly along a stem, one at each node

The larval stage of primitive jawless vertebrates, such as the sea lamprey

Migrating between freshwater and saltwater to breed

An unpaired fin located on the underside of a fish, posterior to the anus

Plant structure located in the stamen (male organ) of the flower that contains the pollen

The male sex organ of algae, mosses, ferns, fungi, and other nonflowering plants

A small circular area; small space that separates the carapace in crayfish

Mode of reproduction that does not involve meiosis; offspring arise from a single parent and inherit genes only from that parent

The angle formed between two structures on a plant, such as a leaf and a stem

In an axil; growing in an axil, as buds

A living organism whose growth or activity results in the impairment or degradation of something, such as a ship’s hull or mechanical equipment

Small, specialized, leaf-like structures at the base of a flower or leaf

A small bulb, or bulb-shaped growth arising from the leaf axil or replacing the flowers; capable of producing a new plant when separated from the parent plant

Strong, silky fibers made from proteins that are used by mussels or other bivalves to attach to rocks, pilings, or other substrates

A hard, bony or chitinous case or shield covering the dorsal (upper) part of an animal, such as a turtle or crab

Directed towards the hind part of the body

The tail fin; located at the end of the caudal peduncle and used for propulsion

Specialized organelles found in plant cells and other eukaryotic organisms where photosynthesis occurs

Small crustaceans in the order Cladocera which are commonly found in most freshwater habitats

Small, inconspicuous, self-pollinating flowers, often more fruitful than showier ones on the same plant

Large family of flowering plants with individual flowers forming clusters or groups of flowers arranged on a stem, which gives it the appearance of a single flower

The eye of most insects and some crustaceans, consisting of multiple light-sensitive parts, each serving to focus light on the retina to form a portion of an image

Growing by spreading out and staying close to the ground

Falling off or shedding at a particular season or stage of growth, such as trees shedding their leaves annually

Non-living, particulate organic material; any disintegrated material or debris

The difference in appearance between males and females of the same species

Having male and female reproductive organs on separate individuals of the same species

Caudal tail shape; vertebrae extend to the tip of the tail and the tail is symmetrical and expanded

Are located on the back of a fish and serve to protect against rolling and assist in sudden turns and stops; can have up to three

Caudal fin with a slight inward curve

Plants with leaves that extend above the water surface, usually found in shallow water

Growing on the surface of a rock

Growing on another plant

The breeding form of male crayfishes

Long, slender, whip-like extensions of certain cells or unicellular organisms, used mainly for movements

The side of the body between the ribs and the hips

A form of asexual reproduction where an organism is split into fragments that develop into mature, fully grown individuals that are clones of the original organism

The seed-bearing portion of a plant

Elongated and spindle-shaped at both ends; fish with this body shape are capable of swimming very fast

Specialized appendages of various arthropods used in reproduction or egg-laying

A stiff, hair-like organelle attached near the flagella in a group of algae called haptophytes; may function in attachment, feeding, or avoidance

The dense inner part of a tree trunk

Organism that has reproductive organs associated with both male and female sexes

Caudal tail shape; vertebrae extend into the upper lobe of the tail, making it longer (as in sharks)

Caudal tail shape; fin appears superficially symmetric but in fact the vertebrae extend for a very short distance into the upper lobe of the fin

The mixing of different species or varieties of animals or plants to produce hybrids of those species

A cluster or arrangement of flowers on an axis

A lateral ridge found on the caudal peduncle of many fast-swimming fishes that provides stability and support to the caudal fin

A series of sensory pores along the head and sides of a fish and some amphibians by which water currents, vibrations, and pressure changes are detected

Flattened from side to side; fish with this body shape usually do not swim rapidly but have exceptional maneuverability

Individual blades found in a compound leaf

A larger, outer bract which, along with the palea, serves to contain the floret(s) held within and provides a protective covering for the developing floret as well as for the seed after ripening

Thin, membranous extension of the leaf sheath on the upper surface of the leaf; may be hairy or bristly, hard or soft

Caudal fin shaped like a crescent moon

The edge of a leaf

The central vein of a leaf that runs from the tip to the base of the leaf

Having male and female reproductive structures on the same plant

Having only one type or representative; such as a genus containing only one species

One of several variant forms of an animal or plant

The hard, pearly, iridescent substance forming the inner layer of a mollusk shell

A knob, or joint of a stem from which leaves, roots, shoots, or flowers may arise

Usually small, raised structures on regions of the head, body or fin rays where two individuals come in contact to breed; may function to maintain body contact between the sexes during spawning

Dry fruit having a hard shell which usually contains only one seed; nutlets are very small nuts

Invisible or indistinct

A sheath around a stem or node formed by two or more stipules

The female sex organ of certain algae and fungi; typically a rounded cell or sac containing oospheres

A structure that acts as a lid or covering to close the aperture of a mollusk’s shell when the animal is retracted

Two leaves emerging from one node directly across from one another; leaves occurring in pairs

Having several lobes (typically 5-7) whose mid-ribs all radiate from one common point

A many-branched inflorescence

Relating to the open sea

Each pair of fins on the underside of a fish’s body, attached to pelvic girdle and helping to control direction

The membrane that lines the abdominal cavity and covers most of the abdominal organs

A leaf stalk

Relating to the pharynx, which is the membrane-lined cavity behind the nose and mouth that connects them to the esophagus

Having pistils (female flowers) but no stamens (male flowers)

The female fertilizing organs of a flower

The ventral surface of a turtle shell

Caudal tail shape; vertebrae extend to the tip of the tail and the tail is symmetrical but not expanded

A filamentous outgrowth on the underside of some plants, especially mosses, serving to anchor the plant and conduct water

A creeping underground stem

Leaves arranged in a radiating pattern at the base or top of the plant

A slender, creeping stem that puts forth roots from nodes, spaced at intervals along its length; new plants eventually grow from the nodes and can become detached from the parent plant

A thickened horny or bony plate or large scale; such as on the shell of a turtle, underside of a snake, back of a crocodile, etc.

Part of the outer floral leaves; usually green

A sharply toothed leaf margin

Sitting directly on a main stem or branch without the support of a leaf stalk

The extension of the leaf that surrounds the stem

A flower or fruit-bearing stalk

A stem or similar structure that supports a plant part such as a flower, flower cluster, or leaf

The male fertilizing organ of a flower

Having stamens (male flowers) but no pistils (female flowers)

A small, paired, leaf-like appendage at the base of a leaf stalk in certain plants, such as roses and beans

A horizontally creeping stem on the surface of the soil

Plants growing with their root, stems, and leaves completely under the surface of the water

A line or junction of adjacent animal or plant parts such as the juncture between whorls of a mollusk shell, or the junction between the valves of a bivalve shell

The last segment in the abdomen, or terminal appendage in crustaceans, chelicerates, and embryonic insects

Situated at the end or extremity

Spores that live in tubifex worms and can infect other fish with whirling disease

Appearing to end abruptly, shortened, cut off at the end

The short, thickened, fleshy, food-storing portion of an underground stem with many surface buds; shaped like a tiny potato

A small rounded projection, especially on the bone or on the surface of a plant or animal

Muddiness created by stirring up sediment or having foreign particles suspended

A young scaly shoot budded off from underground stems; detachable winter bud used for survival when conditions are unfavorable

A form of asexual reproduction of a plant where new plants grow from parts of the parent plant

The free-swimming, planktonic larva of certain aquatic mollusks such as zebra mussels

Relating to the underside of an animal or plant

A pattern of spirals or concentric circles; In plants: an arrangement of three or more leaves, flowers, or bracts radiating from a common node, spread at intervals along the stem.