Biology-Key Definitions

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Nutrition
taking in of nutrients which are organic substances and mineral ions, containing raw materials or energy for growth and tissue repair, absorbing and assimilating them
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Excretion
removal from organisms of toxic materials, the waste products of metabolism and substances in excess of requirements (carbon dioxide, urea, salts)
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Respiration
the chemical reactions that break down nutrient molecules in living cells to release energy
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Sensitivity
the ability to detect or sense changed in the environment-stimuli-and to make responses
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Reproduction
the processes that make more of the same kind of organism
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Growth
a permanent increase in size and dry mass by an increase in cell number or cell size or both
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Movement
an action by an organism or part of an organism causing a change of position or place
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Tissue
a group of cells with similar structures, working together to perform a shared function
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Organ
a structure made up of a group of tissues, working together to perform specific functions
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Organ System
a group of organs with related functions, working together to perform body functions
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Diffusion
the net movement of molecules from a region of their higher concentration to a region of their lower concentration down a concentration gradient as a result of their random movement
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Active Transport
movement of ions in or out of a cell though the cell membrane, from a region of their lower concentration to a region of their higher concentration against a concentration gradient, using energy released during respiration
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Osmosis
the diffusion of water molecules from a region of their higher concentration-dilulte-to a region of their lower concentration-concentrated-, through a partially permeable membrane
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Catalyst
a substance that speeds up a chemical reaction and is not changed by the reaction
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Enzyme
proteins that function as biological catalysts
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Photosynthesis
the fundamental process by which plants manufacture carbohydrates from raw materials using energy from light
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Limiting Factor (of photosynthesis)
something present in the environment in such short supply that it restricts life processes
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Ingestion
taking substances into the body through the mouth
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Egestion
passing out of food that has not been digested, as faeces, through the anus
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Digestion
the breakdown of large, insoluble food molecules into small, water-soluble molecules using mechanical and chemical processes
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Absorption
movement of digested food molecules through the wall of the intestine into the blood or lymph
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Assimilation
movement of digested food molecules into the cells of the body where they are used, becoming part of the cells
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Deamination
removal of the nitrogen containing part of the amino acids to form urea, followed by the release of energy from the remainder of the amino acids
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Transpiration
evaporation of water at the surfaces of the mesophyll cells followed by loss of water vapour from plant leaves, through the stomata
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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
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Respiration
the chemical reactions that breakdown nutrient molecules in living cells to release energy
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Aerobic Respiration
the release of a relatively large amount of energy in cells by the breakdown of food substances in the presence of oxygen
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Anaerobic Respiration
the release of a relatively small amount of energy by the breakdown of food substances in the absence of oxygen
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Sense Organs
a group of receptor cells responding to specific stimuli: light, sound, touch, temperature and chemicals
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Hormone
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
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Geotropism
response in which a plant grows towards or away from gravity
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Phototropism
response in which a plant grows towards or away from the direction from which light is coming
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Homeostasis
maintenance of a constant internal environment
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Drug
any substance taken into the body that modifies or affects chemical reactions in the body
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Asexual Reproduction
the process resulting in the production of genetically identical offspring from one parent
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Sexual Reproduction
the process involving the fusion of a haploid nuclei to form a diploid zygote and the production of genetically dissimilar offspring
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Pollination
the transfer of pollen grains from the male part of the plant -anther of stamen- to the female part of the plant -stigma-
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Development
increase in complexity
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Inheritance
the transmission of genetic information from generation to generation
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Chromosome
a thread of DNA, made up of a string of genes
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Gene
a length of DNA that is the unit of heredity and codes for a specific protein, a gene may be copied and passed on to the next generation
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Allele
any of two or more alternative forms of a gene
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Haploid Nucleus
a nucleus containing a single set of unpaired chromosomes (sperm and egg)
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Diploid Nucleus
a nucleus containing two sets of chromosomes (body cells)
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Mitosis
nuclear division giving rise to genetically identical cells in which the chorosome number is maintained by the exact duplication of chromosomes
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Meiosis
reduction division in which the chromosome number is halved from diploid to haploid
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Genotype
genetic make up of an organism in terms of the alleles present (TT or Tt or tt)
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Phenotype
physical or other features of an organism due to both its genotype and its enivornment
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Homozygous
two identical alleles of a particular gene (tt or TT), two identical homozygous individuals that breed together will be pure-breeding
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Heterozygous
two different alleles of a particular gene (Tg), not pure breeding
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Dominant
an allele that is expressed if it is present (T)
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Recessive
an allele that is only expressed when there is no dominant allele of the gene present (t)
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Mutation
a change in gene or chromosome
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Natural Selection
the greater chance of passing on of genes by the best adapted organisms
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Genetic Engineering
taking a gene from one species and putting it into another species
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Food Chain
a chart showing the flow of energy from one organism to the next beginning with a producer
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Food Web
a network of interconnected food chains showing the energy flow through part of an ecosystem
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Producer
an organism that makes its own organic nutrients, usually using energy from sunlight, through photosynthesis
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Consumer
an organism that gets its energy by feeding on other organisms
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Herbivore
an animal that gets in energy by eating plants
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Carnivore
an animal that gets its energy by eating other animals
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Decomposer
an organism that gets its energy from dead or waste organic matter
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Ecosystem
a unit containing all of the organisms and their environment, interacting together in a given area
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Trophic Level
the position of an organism in a food chain, food web or pyramid of biomass, numbers or energy
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Population
a group of organisms of one species, living in the same area at the same time
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Other cards in this set

Card 2

Front

removal from organisms of toxic materials, the waste products of metabolism and substances in excess of requirements (carbon dioxide, urea, salts)

Back

Excretion

Card 3

Front

the chemical reactions that break down nutrient molecules in living cells to release energy

Back

Preview of the back of card 3

Card 4

Front

the ability to detect or sense changed in the environment-stimuli-and to make responses

Back

Preview of the back of card 4

Card 5

Front

the processes that make more of the same kind of organism

Back

Preview of the back of card 5
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