Definitions Flashcards
Diffusion
the net movement of molecules from a region of higher concentration to a region of lower concentration down the concentration gradient as a result of their random movement
Osmosis
the diffusion of water molecules from a region of their higher concentration to a region of their lower concentration, through a partially permeable membrane
Enzymes
proteins that function as biological catalysts
Photosynthesis
the fundamental process by which plants manufacture carbohydrates from raw materials using energy from light
Ingestion
taking substances into the body through the mouth
Digestion
the breakdown of large insoluble food molecules into small, water-soluble molecules using mechanical and chemical processes
Egestion
passing out of food that has not been digested, as faeces, through the anus
Absorption
movement of
digested food molecules through the wall
of the intestine into the blood.
Transpiration
evaporation of water
at the surfaces of the mesophyll cells
followed by loss of water vapour from plant
leaves, through the stomata
Translocation
movement of sucrose and amino acids
in phloem; from regions of production
to regions of storage or to regions of
utilisation in respiration or growth
Aerobic respiration
the release of
a relatively large amount of energy in cells
by the breakdown of food substances in
the presence of oxygen
Anaerobic respiration
the release
of a relatively small amount of energy by
the breakdown of food substances in the
absence of oxygen
Hormone
a chemical substance,
produced by a gland, carried by the blood,
which alters the activity of one or more
specific target organs and is then destroyed
by the liver
Geotropism
a
response in which a plant grows towards or
away from gravity
Phototropism
a
response in which a plant grows towards or
away from the direction from which light is
coming
Homeostasis
the maintenance of
a constant internal environment
Asexual reproduction
the process
resulting in the production of genetically
identical offspring from one parent
Sexual reproduction
the process
involving the fusion of haploid nuclei to
form a diploid zygote and the production of
genetically dissimilar offspring.
Pollination
as the transfer of pollen
grains from the male part of the plant
(anther or stamen) to the female part of the
plant (stigma)
Food chain
the flow of energy from one organism to the next beginning with a producer
Food web
a network of interconnected food chains showing the energy flow through part of an ecosystem
Producer
an organism that makes its own organic nutrients, usually using energy from sunlight and through photosynthesis
Consumer
an organism that gets its energy by feeding on other organisms
Herbivore
an animal that gets its energy by eating plants
Carnivore
an animal that gets its energy by eating other animals
Decomposer
an organism that gets its energy from dead or waste organic matter
Ecosystem
a unit containing all of the organisms and their environment interacting together in a given area
Trophic level
the position of an organism in a food chain or food web
