Definitions Flashcards
Scientific Method
A process of investigation in which problems are identified and their suggested explanation are tested by carrying out experiments
Observation
When something is noticed
Hypothesis
An educated guess based on observation
Experiment
Designed to test a hypothesis
Data
Consista of the measurements, observations or information gathered from experiments
Conclusion
A summary of the results of an experiment
Theory
A hypothesis that has been supported by many different experiments
Principle/Law
Arises from a theory that has been shown to be valid when fully tested over a long period of time
Variable
A factor that may change in an experiment
Control
Used to provide a comparison against which the actual experiment can be judged
Replicate
A repeat of an experiment
Doubke Blind
Both the investigator and the participant are unaware of the nature of the treatment the participant is receiving
Ethics
Relates to whether conduct is right or wrong
Organism
A living thing
Metabolism
The sum of all the chemical reactions in an organism
Continuity of life
Living things arise from other living things of the same type
Organism
Living things are are composed of cells, tissues, organs and organ systems
Nutrition
The way organism obtain and use food
Excretion
The removal of waste products of metabolism of the body
Response
The way in which all living things react to changes in their environment
Sexual reproduction
Involves the union of sex cells
Asexual reproduction
Does not involve the union of cells and only involves one parent
Biomolecules
Chemicals that are made inside a living things
Biomolecules
Chemicals that are made inside a living things
Phospholipids
Fat-like substances in which one of the fatty acids is replaced by a phosphate group or has a phosphate group added to it.
Anabolic reaction
Use energy to convert smaller molecules into larger molecules
Catabolic reaction
Release energy when a complex molecules is broken down to a simpler form
Ecology
The study of the interactons between living things and between organisms and their environment
Biosphere
That part of the planet containing living organism
Ecosystem
A group of clearly distinguished organisms that interact with their environment as a unit
Habitat
The place where a plant pr animal lives
Population
All the members of the same species living in an area
Community
All different populations in an area
Abiotic factor
Non-living factors
Biotic factor
Living factors
Climatic factors
Refer to weather over a long period of time
Edaphic factor
Relate to soil
Producers
Organisms that carry out photosynthesis
Flora
All the plants in an ecosystem
Consumers
Organisms that take in food from another organism
Fauna
All the animals in an ecosystem
Decomposer
Organism that feed in dead organic matter
Food chain
A sequence of organisma in which each one is easten by the next member in the chain
Trophic level
A feeding stage in a food chain
Food web
Consists of two or more inter-linked food chains
Pyramid of numbers
Represents the nunber of organisms at each trophic level in a food chain
Niche
The functional role it plays in the community
Nutrient recycling
The way in which elements such as carbon and nitrogen are exchanged between the living and non-living components of an ecosystem
Nitrogen fixation
The conversion of nitrogrn gas into ammonia, ammonium or nitrate
Nitrification
The conversion of ammonia and ammonium compounds to nitrite and then nitrate
Denitrification
The conversion of nitrates to nitrogen gas
Pollution
Any harmful additon to the environment
Conservation
The wise management of the existing natural resources in an ecosystem in order to maintain a wide range of habitats and prevent the death and extinction of organisms.
Competition
When organisms actively struggle for a resource that is in short supply
Intra-specific competition
Takes place between members or the same species
Inter-specific competition
Occurs between membere of different species
Contest competition
There is an active physical contedt between two individual organisms
Scramble competition
All the competing individuals gets some of the resources
Predation
The catching, killing and eating of another organism
Predator
An organism that catches, kills and eats another organism
Prey
The organism that is eaten by the predator
Parasitism
Occurs when two organisms of different species live in close associations with each other and one organism obtains its food from and to the disadvantage of the second organism
Symbiosis
Ooccurs when two organisms of different species live in close association and at least one of them benefits
Qualitative study
Records the presence and absence of organisms
Quantitative study
Records the number of organisms that are present
Adaptation
Any alteration that improves an organisms chances of survival and reproduction
Key
Naming organisms by answering a seriee if questions with alternative answers
Percentage cover
An estimate of the amount of ground in a quadrat covered by each species
Frequency
The chance of finding a named species with any one throw of a quadrat
Protoplasm
All the living parts of a cell
Cytoplasm
The living materials in a cell outside the nucleus
Chromatin
The name given to chromosomes they are elongated and not dividing
Prokaryotic
Do not have a nucleus or membrane enclosed cell organelles
Eukaryotic
Have a nucleus and cell organelles all of which are enclosed by membranes
Tissue
A group of similar cells that are modified to carry out the same function
Tissue culture
The growth of cells in or on a sterile nutrient medium outside an organism
Organ
A structure composed of a number of tissues that work together to carry out one or more functions
Solar energy
Energy from the sun
Cellular energy
The energy stored in the bonds of biomolecules
Catalyst
A substance that speeds up a reaction without itself being used up in the reaction
Enzyme
Proteins that speed up a reaction without being used up in the reaction
Substrate
The substance with which an enzyme reactd
Product
The substancd the enzyme forms
Denatured enzyme
An enzyme that has lost its shape and can no longer function
Bioprocessing
The use of enzyme-controlled reactions to produce a product
Bioreactor
A vessel or container in which living cells or their products are used to make a product
Immobilised enzyme
Enzymes that are attached or fixed to each other or to an inert material
Enzyme specificity
Each enzyme will react with only one particular substrate
Optimum pH
The pH value at which the enzyme works best
Photolysis
The splitting of water by light
Aerobic respiration
The controlled release if energy from food using oxygen
Anaerobic respiration
The controlled release of energy from food without using oxygen
Fermentation
Another name for anaerobic respiration
Biotechnology
The use of living things or their components to manufacture useful products or to carry out useful reactions
Glycolysis
The conversion of glucose into two molecules of pyruvic acid
Selectively permeable
Allows some but not all molecules to pass through
Diffusion
The spreading out of molesioes from a region if high concentration to a region if low concentration across a selectively permeable membrane
Osmosis
The movement of water molecules across a semi-permeable membrane from a region of high water concentration to a region of low water concentration
Turgor
The outward pressure of the cytoplasm and vacuole against the cell wall of the plant
Cell continuity
Cells develop from pre-existing cells
Chromosomes
Coiled threads of DNA and protein that become visible in the nucleus at cell division
Gene
A section of DNA that contains the instructions for the formation of a protein
Haploid cell
Has one set of chromosomes
Diploid
Has two sets of chromosomes
Homologous pair
Two chromosomes of similar size with the same sequence of genes
Cell cycle
The changes that take place in a cell during the period between one cell division and the next
Interphase
The phase in the cell cycle when the cell is not dividing
Mitosis
A form of nuclear division in which one nucleus divides to form two nuclei each containing the same number of chromosomes with identical genes
Meiosis
A form of nuclear division in which the four daughter nuclei contain half the chromosome number of the parent nucleus
Centromere
The point at which the chromosomes are attached in a double strandd chromosome
Heredity
The passing on of features from parents to offpsring by means of genes
Gene expression
The way in which the genetic information in a gene is decoded in the cell and used to make a protein
Characteristics
Traits or features that are inherited genetically
Non-coding DNA
DNA that does not cause the production of a protein
Genetic code
The sequence of baaes in DNA that provide the instructions for a cell to form a protein
Triplet/Codon
A sequence of three bases in DNA that act as a code for an amino acid
Triplet/Codon
A sequence of three bases in DNA that act as a code for an amino acid
DNA profile
A method of making a unique pattern of bands from the DNA of a person which can then be used to compare with the DNA profile of another person
Forensic medicine
The way in which medical knowledge is used in legal situations
Genetic screening
Testing DNA for the presence or absenfe of a particular gene or an altered gene
Transcription
The copying of a sequence of genetic bases in DNA onto messenger RNA
Translation
The conversion of a sequence of genetic bases on messenger RNA into a sequence of amino acids
Purine
Adenine and Guanine
Pyrimidine
Thymine and Cytosine
Anticodon
A sequence of three basss in tRNA that are complementary to a sequence of three bases on mRNA
Gametes
Haploid cells that are capable of fusion
Fertilisation
The union of 2 gametes to form a single cell called a zygote
Dominant
The allele that prevents the recessive allele from being expressed
Recessive
The allele that is prevented from being expressed by a dominant allele
Allele
Different forms of the same gene
Locus
The position of a gene on a chromosome
Genotype
The genetic makeup of an organism
Phenotype
The physical make-up of an organism
Progeny
Refers to offspring that are produced
Homozygous
2 alleles are identical
Heterozygous
The alleles are different
Punnett square
The grid used to show the ratio of the genotypes of the progeny in a genetic cross
Incomplete dominance
Neither allele is dominant or recessive with respect to the other. Both alleles are equally expressed in the heterozygous genotype to produce an intermediate phenotype
Pedigree
A diagram showing the genetic history of a group of related individuals
Law of segregation
Inherited characteristics are controlled by pairs of alleles. These alleles segregate from each other at gamete formation with only one member of the pair being found in each gamete.
Monohybrid cross
The study of a single characteristic
Dihybrid cross
The study of two characteristics
Law of Independent Assortment
When gametes are formed either of a pair of alleles is equally likely to combine with either of another pair of alleles
Linkage
Genes are located on the same chromosome
Sex Linkage
A characteristic is controlled by a gene on a sex chromosome
Classification
Placing objects into group based on similar characteristics
Taxonomy
The science of classifying organisms
Taxonomy
The science of classifying organisms
Species
A group of similar organisms that are capable of naturally interbreeding with each other to produce fertile offspring
Variation
In a group of successfully interbreeding organisms the individual members show different characteristics
Acquired variation
Not inhertied but are learned or developed during life
Inherited variation
Controlled by genes
Mutations
A spontaneous change in the amount or structure of DNA
Mutagens
Agents that cause mutations
Gene mutation
A change in a single gene
Chromosome mutation
A large change in the structure or number of one or more chromosomes
Evolution
The way in which living things change genetically to produce new forms of life over long periods of time
Natural selection
The process by which those organisms with genetically controlled characteristics that allow them to be well adapted to their environment will survive and reproduce to pass on their genes to following generations
Speciation
The production of a new species as a result of evolution
Fossil
The remains of something that lived a long time ago
Genetic engineering
The artificial manipulation or alteration of a gene
Isolation
The removal of a chromosome from the human cell and the plasmid DNA from the bacterium
Ligation
The joining of two sections of DNA to form a single strand
Transformation
The uptake of DNA into a cell
Cloning
The production of identical copies of the bacterium
Expression
The formation of the product by the organism with the recombinant DNA
Cell
The smallest unit of a living thing
Autotrophic
An organism that makes it’s own food
Chemosynthetic
The production of food using energy released from chemical reaction
Heterotrophic
An organism takes in food made by other organisms
Saprophytic
Organisms that take in food from dead organic matter
Parasites
Organisms that take in food from a live host and usually cause it harm
Pathogenic bacteria
Bacteria that cause disease
Antibiotics
Chemicals produced by micro-organisms that stop the growth of, kill other micro-organisms without damaging human tissues
Batch culture
The growth of cells in a sealed container over a short period of time and under ideal conditions until all the nutrients are used up
Continuous flow
The growth of cells in an open container where nutrients are added and the end products are removed all the time at a rate that maintains the volume of liquid and the number of cells
Hypha
A tube or filament in a fungus
Mycelium
A visible mass of hyphae
Obligate parasite
Can only take it’s from a live host
Facultative parasite
Can get its food from a live or a dead host
Facultative parasite
Can get its food from a live or a dead host
Sporulation
The process of making spores
Aseptic/asepsis
Measures are taken to exclude unwanted micro-organisms
Sterile
All micro-organisms are destroyed
Meristem
Plant tissue capable of mitosis
Herbaceous plant
Do not contain wood/aligning
Woody plant
Contain wood or lignin
Node
The point on a stem at which a leaf is attached
Internode
The region on a stem between two nodes
Bud
A potential growth point that may develop into a shoot a left or a flower
Bud
A potential growth point that may develop into a shoot a left or a flower
Venation
The pattern of veins in a leaf
Lignin
Strengthening material found in some plant cell walls
Cotyledon
A seed leaf
Transpiration
The loss of water by evaporation from the leaves and other aerial parts of a plant
Lenticels
Openings in the stems of plants that allow gas exchange
Cohesion
The sticking of similar molecules to each other
Adhesion
When different molecules stick together
Plasma
The liquid part of the blood
Serum
Plasma from which the clotting proteins have been removed
Open circulatory system
Blood leaves blood vessels and flows around the cells of the animals body before re-entering blood vessels again e.g snails, crabs, spiders
Closed circulatory system
Blood remains in a continuous system of blood vessels e.g humans
Blood pressure
The force the blood exerts against the wall of a blood vessel
Blood pressure
The force the blood exerts against the wall of a blood vessel
Valves
Control the direction of the blood flow
Portal system
Blood pathway that begins and ends in capillaries and do not connect directly to the heart
Diastole
When the heart chambers relax
Systole
When the heart chambers contract
Pulse
The alternate expansion and contraction of the arteries
Herbivores
Animals that feed mainly on plants e.g sheep
Carnivores
Animals that feed mainly on animals e.g dogs
Omnivores
Animals that feed on plants and animals e.g badgers
Digestion
The physical and chemical breakdown of food
Peristalsis
A wave of muscular action in the walls of the alimentary canal that moves the contents along
Balanced diet
Contains all the necessary food types in the central proportion
Homeostasis
The ability of an organism to maintain a constant internal environment
Pharynx
The throat
Larynx
The voice box
Inhalation
Breathing in
Exhalation
Breathing out
Ecotherms
Gain or lose hest from or to their external environment
Endotherm
Generate their own heat from metabolic reactions
Filtration
Water and small molecules pass under high pressure from the blood into the nephron
Reabsportion
Molecules pass from the nephron back into the blood
Active transport
Energy in the form ATP is used to move molecules often against a concentration gradient
Secretion
Some substances pass from the blood into the nephron
Osteoclast
Bone digesting cell
Joint
Where two or more bones meet
Synovial fluid
Produced in movable joints to lubricate and reduce friction
Ligaments
String, fibrous slightly elastic tissues that connect bone to bone
Tendons
Strong, flexible, inelastic fibres that connect muscle to bone
Tendons
Strong, flexible, inelastic fibres that connect muscle to bone
Antagonistic pair
Tow muscles that have opposite effects to each other
Pathogen
An organism that cause disease
Immunity
The ability to resist infections
General defence system
Acts as a barrier to all pathogens attempting to gain entry to the human body
Specific defence system
Attacks a particular pathogen
Antigen
A foreign molecule that stimulates the production of antibodies
Antibody
A protein produced by white blood cells in the response to a specific antigen
Induced immunity
The ability to resist disease caused by specific pathogens by the production of antibodies
Active immunity
The production of a person’s own antibodies in response to a foreign antigen that enters the body
Natural active immunity
Occurs when a pathogen enters the body in the normal way
Artificial active immunity
When a pathogen is medically introduced into the body
Vaccine
Non disease causing dose of a pathogen which triggers the production of antibodies
Passive immunity
When individual are given antibodies that were formed by another organism
Natural passive immunity
When a child gets antibodies from its mother
Artificial passive immunity
When a person is given an injection containing antibodies made by another organism
Vaccination
The administration of a non-disease causing dose of a pathogen to stimulate the production of antibodies.
Immunization
When we produced or are injected with antibodies against a pathogen
Plasma B cells
Produce antibodies
Memory B cells
Survive years after the infection is eliminated and can make the specific antibody if the same infection later enters the body
Helper T cells
Stimulate B cells and Killer T cells
Killer T cells
Destroy abnormal human body cells
Suppressor T cells
Inhibit the immune response
Memory T cells
Survive for years after the infection is eliminated and can stimulate the specific B cells and killer T cells if the same infection later enters the body
Bacteriophage
A virus that infects bacteria
Gamete
Haploid cells that are capable of fusion
Pollination
The transfer if pollen from an anther to a stigma of a flower from the same species
Self pollination
Involves the transfer of a pollen from an anther to a stigma on the same plant
Cross pollination
Involves the transfer of a pollen from an anther to a stigma on a different plant
Fertilisation
The union of the Male and female gametes to form a diploid zygote
Radical
The part of the plant embryo that develop into the root
Plumule
The part of the plant embryo that develops into the shoot
Non-endospermic seed
Has no endosperm when fully formed
Endospermic seed
Contains some endosperm when fully formed
Fruit
Developed ovary
Dispersal
The transfer of a seed or fruit away from the parent plant
Germination
The regrowth of the embryo after a period of dormancy if the environmental conditions are suitable
Vegetative propagation
Asexual reproduction in plants it only involves one parent and can be artificial or natural
Natural vegetative propagation
Involves forming new plants from a stem, roots leaf or bud
Runners
Horizontal stems that runs above ground and from which new plants grow
Root tubers
A swollen underground root that remains dormant during winter and from which new plants grow
Bulbs
Modified bud
Cutting
A portion of a plant that is removed from the parent plant and grown into a new Independent plant
Grafting
The joining and uniting of part of one plant with a second part.
Layering
The growth of a new plant from a stem that is still attached to the parent plant
Micro propagation
The growth of plants from small pieces of tissue under sterile conditions on a specifically selected medium
Gonad
An organ that produces sex cells in animals
Puberty
Beginning of sexual maturity
Secondary sexual characteristics
Features that distinguish males from females apart from the sex organs themselves
Ovulation
The release of an egg from the ovary
Menstrual cycle
A series of events that occur every 28 days on average in the female if fertilisation has not taken place
Menstruation
The discharge of the lining of the uterus and the in infertilised egg
Insemination
The release of the semen in the vagina just outside the cervix
Implantation
The embedding of the fertilised egg into the lining of the uterus
In vitro fertilization
Removing eggs from an ovary and fertilizing them outside of the body
Morula
Solid ball of cells formed from a zygote by mitosis
Blastocyst
A hollow ball of cells formed from a morula
Germ layers
Basic layers of cells in the blastocyst from which all adult tissue and organs will form
Birth control
Methods taken to limit the number of children that are born
Contraception
The deliberate prevention of fertilisation or pregnancy
