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Academia - Collins Scientific Pocket Dictionaries - Biology
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pest
peste f

pest. Any living organism is harmful to humans. The following table shows some examples:

Example of pest - effect on humans

Weeds, locusts
Reduces the growth of plants and crops

Foot and mouth virus
It causes diseases in domestic animals

Woodworm wet rot fungus
Damages buildings

Mosquitoes, lice
Transmits human diseases

Pest control methods include the following:
(a) Spraying with chemicals (pesticides).
(b) Using natural predators for pests.
(c) Introduction of parasites and population pathogens into the pest pathogen population.
(d) Introducing sterile individuals into the pest population, which reduces the ability to reproduce.


pesticide
pesticide m

Pesticide. A chemical compound, often used by spray, that kills pests or prevents their growth. And from
Examples:

(a) Herbicides: weed killers, such as paraquat.
(b) Fungicides: angiosperms such as organic mercury compounds, organomer cury.
(c) Insecticides: flying insect sprayers used in homes, and sprayers launched from aircraft against locusts. The pesticide DDT (its use is now banned in many countries) was used against mosquitoes and lice.

Pesticides have disadvantages:
(a) It may kill organisms other than the target pest.
(b) The concentration of the pesticide increases as it passes through the food chain.
(c) Some pesticides decompose slowly and may accumulate in harmful doses within organisms.
(d) When susceptible organisms are killed, they allow resistant organisms to grow and reproduce in conditions where there is less competition.


phagocytosis
phagocytose f

phagocytosis The process by which cells (phagocytes) surround food particles, encapsulate them, and then digest them. Phagocytosis is a method of nutrition used by some unicellular animals (protozoans), such as Amoeba. It is also one of the ways in which white blood cells destroy invading blood cells.


pharynx
pharynx m

pharynx. A section of the alimentary canal of a vertebrate animal located between the mouth and the esophagus. In humans, it forms the back of the nose and throat. When stimulated by food, swallowing begins.


phenomenon
phenotype m

Phenotype The physical characteristics of an organism, resulting from the influence of genotype and environment.
. see monohybrid inheritance


phloem
Phloème m

Bark tissue within plants is transported through...
Carbohydrates from leaves
Cross plant. The bark consists of tubes formed from leaves and columns of living cells in which the horizontal transverse walls have become perforated. This allows carbohydrates to move from one phloem cell to the next, and thus throughout the plant. Because of their structure, the bast tubes are also called sieve tubes.
Look
stem, secondary growth, root and leaf.