Unit Two The Cell DEFINTIONS Start Alphabetical order

Unit Two The Cell DEFINTIONS Start Alphabetical order Go to Section Index These definitions are the work of practising teachers - not the SEC - and may have to be adjusted depending on the precise wording of an exam question. Check SEC marking schemes regularly. E&OE

INDEX 2. 1 2. 3 Cell Structure Cell Continuity 2. 2 2. 4 Cell Metabolism and Enzymes Cell Diversity 2. 5 Genetics All Back to Start

2. 1 Cell Structure Eukaryotic Cell* Prokaryotic Cell* Selectively permeable Back to Start

2. 2 Cell Metabolism and Enzymes Metabolism Enzyme Aerobic respiration Anaerobic respiration Immobilised Enzyme Fermentation Bioreactor Diffusion Photosynthesis Osmosis Turgor Enzyme Specificity Enzyme Denaturation Glycolysis Enzyme Optimum Activity for p. H Back to Start

2. 3 Cell Continuity Cell continuity Chromosome Diploid number Haploid number Cancer Mitosis Meiosis Back to Start

2. 4 Cell Diversity Tissue culture Organ System Back to Start

2. 5 Genetics Allele Coding dna DNA profiling Dominance Evolution Fertilisation Gamete Gene Expression Genetic engineering Genetic screening Genotype Heredity Heterozygous Homozygous Incomplete Dominance Mutation Non-coding dna Phenotype Recessive Species Transcription Translation Variation Mendel’s 1 st Law[Segregation] Mendel’s 2 nd Law[Ind. Assortment] Linkage Sex Linkage Non-nuclear Inheritance Back to Start

Aerobic respiration Allele Anaerobic respiration Bioreactor Cancer Cell continuity Chromosome Coding dna Diffusion Diploid number DNA profiling Dominance Enzyme Denaturation Enzyme Optimum Activity for p. H Enzyme Specificity Eukaryotic Cell* Evolution Fermentation Fertilisation Gamete Gene Expression Genetic engineering Genetic screening Genotype Glycolysis Haploid number Heredity Heterozygous Homozygous Immobilised Enzyme Incomplete Dominance Linkage Meiosis Mendel’s 1 st Law[Segregation] Mendel’s 2 nd Law[Ind. Assortment Metabolism Mitosis Mutation All Non-coding dna Non-nuclear Inheritance Organ System Osmosis Phenotype Photosynthesis Prokaryotic Cell* Recessive Sex Linkage Selectively permeable Species Tissue culture Transcription Translation Turgor Variation Back to Start

Aerobic respiration The release of energy from carbohydrate using oxygen Back to Index subsection Back to Full Index

Allele An alternative form of a gene Back to Index subsection Back to Full Index

Anaerobic respiration The release of energy from carbohydrate without using oxygen. Back to Index subsection Back to Full Index

Bioreactor vessel in which products are made by cells (or organisms) (or enzymes) Back to Index subsection Back to Full Index

Cancer A growth resulting from abnormal and uncontrolled mitosis Back to Index subsection Back to Full Index

Cell continuity Process whereby cells develop from pre-existing cells. Back to Index subsection Back to Full Index

Chromosome A structure made of DNA and protein which can be inherited. Back to Index subsection Back to Full Index

Coding dna That part of the chromosome which carries the information to make a protein Back to Index subsection Back to Full Index

Diffusion The movement of [gas or liquid] molecules from a region of higher concentration to a region of lower concentration. Back to Index subsection Back to Full Index

Diploid number Chromosomes in pairs (two sets of chromosomes. ) Back to Index subsection Back to Full Index

DNA profiling examining DNA / for a pattern or band / to compare Back to Index subsection Back to Full Index

Dominance One allele masks the expression of the other. Back to Index subsection Back to Full Index

Enzyme Biological catalyst Back to subsection Index Back to Full Index

Enzyme Denaturation Permanent Loss of (enzyme) function (or activity) Back to Index subsection Back to Full Index

Enzyme Optimum Activity for p. H the p. H at which an enzyme works best Back to Index subsection Back to Full Index

Enzyme Specificity [The concept that]An enzyme will combine (usually) with only one substrate to form a product. Back to Index subsection Back to Full Index

Eukaryotic Cell* Cells which have a nucleus and other membrane bound organelles. Back to Index subsection Back to Full Index

Evolution (Inheritable) change within a population (or species) / in response to change in the environment / by natural selection/over time Back to Index subsection Back to Full Index

Fermentation Anaerobic respiration Back to Index subsection Back to Full Index

Fertilisation The fusion of 2[haploid] gametes to form a [diploid] zygote Back to Index subsection Back to Full Index

Gamete A haploid sex cell which is capable of fusion Back to Index subsection Back to Full Index

Gene A unit of DNA which codes for the production of a specific protein Back to Index subsection Back to Full Index

Gene Expression The process of using the information on the gene to make a protein Back to Index subsection Back to Full Index

Genetic engineering Manipulation or alteration of genes Back to Index subsection Back to Full Index

Genetic screening Testing (people) for the presence of a (specific) gene or To establish presence or absence of gene(s) Back to Index subsection Back to Full Index

Genotype The genetic make-up of an individual Back to Index subsection Back to Full Index

Glycolysis The process of breaking down glucose into pyruvic acid. Back to Index subsection Back to Full Index

Haploid number Having one set of chromosomes Back to Index subsection Back to Full Index

Heredity The passing on of traits from parent to offspring by means of genes Back to Index subsection Back to Full Index

Heterozygous Has different alleles [for a trait] Back to Index subsection Back to Full Index

Homozygous Has identical alleles [for a trait] Back to Index subsection Back to Full Index

Immobilised Enzyme A biological catalyst which is fixed to an inert material by chemical or physical means. Back to subsection Index Back to Full Index

Incomplete Dominance Neither allele masks the expression of the other. Back to Index subsection Back to Full Index

Linkage Genes located on the same chromosome[ are said to be linked] Back to Index subsection Back to Full Index

Meiosis A form of nuclear division in which one (diploid) nucleus divides to form 4 different (haploid) (daughter) nuclei. Back to Index subsection Back to Full Index

Mendel’s 1 st Law[Segregation] Traits are controlled by pairs of alleles which separate at gamete formation. Each gamete carries only one allele for each trait Back to Index subsection Back to Full Index

Mendel’s 2 nd Law[Ind. Assortment] During gamete formation each member of a pair of alleles may combine randomly with either of another pair Back to Index subsection Back to Full Index

Metabolism All the chemical reactions that occurs in organisms Back to subsection Index Back to Full Index

Mitosis A form of nuclear division in which one nucleus divides to form 2 identical (daughter) nuclei. Back to Index subsection Back to Full Index

Mutation Change in the genetic make up Back to Index subsection Back to Full Index

Non-coding dna That part of the chromosome which does not carry the infomation to make a protein Back to Index subsection Back to Full Index

Non-nuclear Inheritance DNA apart from that found in the nucleus[e. g. mitochondria] that is passed on to the next generation Back to Index subsection Back to Full Index

Organ A group of tissues that work together. Back to Index subsection Back to Full Index

Organ System A group of organs that work together Back to Index subsection Back to Full Index

Osmosis The movement of water molecules from a region of high water concentration to a region of low water concentration across a selectively permeable membrane or The movement of water molecules along a concentration gradient across a selectively permeable membrane. or Movement of water molecules from a more dilute solution to a more concentrated solution across a selectively permeable membrane Back to Index subsection Back to Full Index

Phenotype physical appearance of an organism Back to Index subsection Back to Full Index

Photosynthesis Process where plants make carbohydrate using (sun)light energy (CO 2, water and chlorophyll). Back to Index subsection Back to Full Index

Prokaryotic Cell* Cells which DO NOT have a nucleus and other membrane bound organelles. Back to Index subsection Back to Full Index

Recessive Allele whose expression is masked by dominant allele Back to Index subsection Back to Full Index

Sex Linkage Gene located on X- chromosome or on Ychromosome Back to Index subsection Back to Full Index

Selectively Permeable Only some substances are allowed through Back to Index subsection Back to Full Index

Species Organisms capable of interbreeding and producing fertile offspring. Back to Index subsection Back to Full Index

Tissue Group of similar cells. Back to Index subsection Back to Full Index

Tissue culture Cells grown on (or in) medium or cells grown outside organism Back to Index subsection Back to Full Index

Transcription The process of producing m. RNA using DNA as a template. Back to Index subsection Back to Full Index

Translation The process of making a protein using the m. RNA code as a template Back to Index subsection Back to Full Index

Turgor The state of fullness in a plant cell due to the intake of water. Back to Index subsection Back to Full Index

Variation Difference between members of species or population Back to Index subsection Back to Full Index

The End