tropo-, trop-, -tropal, -trope(s), -tropic, -tropism, -tropia, -tropous, -tropy, trep-

Relating to, or exhibiting, diageotropism; or a growth movement in a plant organ so that it assumes a position at right angles to the direction of gravity.

1. The tendency of a sessile organism (leaf or flower that has no stalk but is attached directly to the stem), or structure, to grow horizontally to the ground or perpendicularly to the line of gravity; such as, a tree branch or root.
2. A response of a plant to gravity in which a part of the plant adopts a horizontal position.
3. The tendency of growing parts; such as, roots, to become oriented at right angles to the direction of gravitational force.

The use of geometric echo-ranging with low-frequency seismographic waves transmitted several miles into the earth's crust to determine the geological composition and characteristics of the area.

Characterized by the orientation movements in plants during darkness in response to gravity.

Orientation movements in plants during darkness in response to gravity.

1. A description of the response of plants toward the pull of gravity.
2. An organism that responds to the force of gravity with movement towards the center of the earth.

1. The response of a plant to gravity, as evidenced by growing patterns; such as, downward root growth and growth curvature.
2. Plant growth or movement in response to gravity.

Primary roots (tap roots) grow vertically towards gravity (positive geotropism) whereas primary shoots grow vertically away from gravity (negative geotropism), though the direction of shoot growth may also be modified by light.

1. A plant that turns or bends in response to sunlight.
2. Any of the genus Heliotropium, a herb or shrub of the borage family.
3. A heliograph that is capable of reflecting solar rays over long distances.

1. Oriented toward sunlight or other light.
2. Describing a plant that grows, or moves, toward the sun.
3. The description of a deice that follows the sun's apparent movement across the sky.

1. Plant movement or orientation in response to the location of sun light.
2. The reversible phenomenon of color change in a solid as the result of exposure to sun light.

1. The turning of a plant toward or away from water.
2. The growth or directional response of an organism toward or away from water or moisture.