Francais dissert

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Phytohormones (plant hormones) are organic molecules that coordinate growth and development.

Tropism is a response to stimuli where a non-motile organism, such as a plant, grows and bends towards or away from that stimulus. This response is similar to taxis, except it describes movement based on growth as opposed to motility.

Gravitropism is directional plant growth in response to gravity.

Allelopathy : To reduce competition they may produce chemicals that inhibit both the germination and growth of neighboring plants.

Allelopathy - The Effect of Natural Poisons on Plant Growth and Development.

Gravitropism - The Effect of Gravity on Plant Growth and Development.

Phytohormones - The Effect of Chemical Messengers on Plant Growth and Development.

Gibberelllins (GAs) are a large family of naturally occurring phytohormones.

PALISADE MESOPHYLL: Elongated photosynthetic cells just beneath the epidermis.

SPONGY MESOPHYLL: Loosely packed photosynthetic cells allowing the movement of O2 and CO2 between the palisade cells and the stomata.

VASCULAR BUNDLE (VEIN): Unit of vascular tissue that conducts the water and nutrients throughout the plant. Contains xylem and phloem.

Stamen (male) : anther + filament

Carpel (female) : Stigma + style + ovary (ovule inside)

Sepal, petal,

Oculars (Eyepieces) : Further magnifies the image (10X) from the objective and puts it in a form and position suitable for viewing.

Revolving Nose Piece : Allows the user to change objective lenses without damaging them.

Objective Lenses : Supplies the initial magnified image of the specimen.

Mechanical Stage : Clips a slide into place and allows user to move slide in the x plane (left to right) using the stage control knob.

Sample Stage : Provides a platform for the specimen and allows user to move the specimen in the y plane (front to back) using the stage control knob.

Coarse and Fine Focus Adjustment Knobs : Adjusts the height of the sample stage relative to the objective to focus the specimen.

Condenser : Collects and concentrates light onto the specimen and projects image onto front lens of the objective in place.

Condenser Adjustment Lever : Controls the distance of the condenser to the sample stage.

Iris Diaphragm Lever : Controls the amount of light entering and leaving the condenser.