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 2.5 Genetics 2.2 2.4 All Cell Structure Cell Continuity Cell Metabolism and Enzymes 2.4 Cell Diversity All Back to Start

2.1 Cell Structure Eukaryotic Cell* Prokaryotic Cell* Selectively permeable Back to Start

2.2 Cell Metabolism and Enzymes Metabolism Aerobic respiration Enzyme Anaerobic respiration Immobilised Enzyme Fermentation Bioreactor Diffusion Photosynthesis Osmosis Turgor Enzyme Specificity Enzyme Denaturation Glycolysis Enzyme Optimum Activity for pH 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 Tissue culture Organ Organ System Back to Start

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

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

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

An alternative form of a gene 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

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

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

Process whereby cells develop from pre-existing cells. 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

Chromosomes in pairs (two sets of chromosomes.) 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

One allele masks the expression of the other. 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

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

Enzyme Optimum Activity for pH the pH 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

Cells which have a nucleus and other membrane bound organelles. 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

Anaerobic respiration Fermentation Anaerobic respiration Back to Index subsection Back to Full Index

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

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

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

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

Manipulation or alteration of genes 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

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

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

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

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

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

Has identical alleles [for a trait] 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

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

Genes located on the same chromosome[ are said to be linked] 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 1st 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 2nd 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

All the chemical reactions that occurs in organisms 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

Change in the genetic make up 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

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

A group of organs that work together 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 . 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

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

Photosynthesis Process where plants make carbohydrate using (sun)light energy (CO2, water and chlorophyll). Back to Index subsection Back to Full Index

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

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

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

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

Organisms capable of interbreeding and producing fertile offspring. 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

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

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

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

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

The End