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photosynthesis
photosynth f

Photosynthesis. The process by which green plants make carbohydrates from carbon dioxide and water. The energy needed for the reaction comes from sunlight, which is absorbed by the chlorophyll within the chloroplasts. Oxygen is released as a side product. Overall interaction:

Carbon dioxide 6CO2 + water 6H2O >
Light energy chloroplast > carbohydrates C6H12O6
+ Oxygen 602

In fact, photosynthesis takes place in a reaction of
Two stages including:

(a) Light reaction: Light energy is used to split water into hydrogen (passes to the next stage) and oxygen (released).

(b) Dark reaction: where the hydrogen of the light reaction joins with carbon dioxide
To form carbohydrates. Photosynthesis is the source of all food and the basis of food chains, while the release of oxygen compensates for the oxygen content in the atmosphere.


phototropism
phototropism m

Phototropism. tropism related to light. Plant branches and twigs are positively phototropic, meaning they grow toward the light.


phylum
phylum m

Section. A unit used in classifying living organisms and consisting of one or more classes. The term division is often replaced in plant classification.


pinna
pavillon m de l'oreille

Auricle. A fold of skin and cartilage at the outer end of the external ear in mammals. See ear.


pituitary gland
hypophyse f

Pituitary gland. An endocrine gland located at the base of the brain of a vertebrate animal. This gland produces many hormones, including ADH and FSH, and many of these hormones regulate the activity of other endocrine glands. The brain regulates the secretion of the pituitary gland itself in many cases. See hormones.

placenta
placenta m

placenta. An organ that grows during pregnancy in the uterus of the animal, the breast, and forms an intimate connection between the blood circulation of the mother and the fetus. The placenta allows food and oxygen to pass to the foetus and removes carbon dioxide and urea from it.


plankton
plancton m

Microscopic zooplankton and phytoplankton plants float in the surface waters of lakes and seas. Plankton are important as the basis for aquatic food chains.


plasma
plasma m

Plasma is the clear liquid of the blood of a vertebrate animal
To which the blood cells attach, it is an aqueous solution in which many compounds are dissolved as it moves throughout the body. Examples:

waste
Carbon Dioxide
Glucose
Urea

Digested food
Amino acids
hormones
Plasma proteins
Sodium chloride


plasma proteins
Plasma proteins

Plasma proteins proteins analyzed in
Plasma: blood in vertebrate animals. Such as: antibodies, fibrinogen, and some hormones.


plasmolysis
plasmolyse f

Cytoplasmosis. Loss of water from the cell
Plant when the cell is surrounded by a solution whose water concentration is less than the concentration of the cell's vacuole (such as a strong salt or sugar solution). Osmosis causes water to pass out of the cell and the vacuole shrinks, attracting the cytoplasm away from the cell wall.

Cytoplasmic cell
Water leaves by osmosis
Swollen plant cell
Salt or sugar solution
cell
gap
Nucleus wall
Cytoplasm

Cytokinesis can be performed and reversed experimentally, but continued cytokinesis leads to cell death. This osmotic death rarely occurs naturally, but it can result from adding an excess of fertilizer to plants because this leads to the dissolution of the cytoplasm or what is called plant burning.