Definitions Flashcards
(291 cards)
1
Q
Scientific Method
A
A process of investigation in which problems are identified and their suggested explanation are tested by carrying out experiments
2
Q
Observation
A
When something is noticed
3
Q
Hypothesis
A
An educated guess based on observation
4
Q
Experiment
A
Designed to test a hypothesis
5
Q
Data
A
Consista of the measurements, observations or information gathered from experiments
6
Q
Conclusion
A
A summary of the results of an experiment
7
Q
Theory
A
A hypothesis that has been supported by many different experiments
8
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Principle/Law
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Arises from a theory that has been shown to be valid when fully tested over a long period of time
9
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Variable
A
A factor that may change in an experiment
10
Q
Control
A
Used to provide a comparison against which the actual experiment can be judged
11
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Replicate
A
A repeat of an experiment
12
Q
Doubke Blind
A
Both the investigator and the participant are unaware of the nature of the treatment the participant is receiving
13
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Ethics
A
Relates to whether conduct is right or wrong
14
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Organism
A
A living thing
15
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Metabolism
A
The sum of all the chemical reactions in an organism
16
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Continuity of life
A
Living things arise from other living things of the same type
17
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Organism
A
Living things are are composed of cells, tissues, organs and organ systems
18
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Nutrition
A
The way organism obtain and use food
19
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Excretion
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The removal of waste products of metabolism of the body
20
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Response
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The way in which all living things react to changes in their environment
21
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Sexual reproduction
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Involves the union of sex cells
22
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Asexual reproduction
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Does not involve the union of cells and only involves one parent
23
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Biomolecules
A
Chemicals that are made inside a living things
24
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Biomolecules
A
Chemicals that are made inside a living things
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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.
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Anabolic reaction
Use energy to convert smaller molecules into larger molecules
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Catabolic reaction
Release energy when a complex molecules is broken down to a simpler form
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Ecology
The study of the interactons between living things and between organisms and their environment
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Biosphere
That part of the planet containing living organism
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Ecosystem
A group of clearly distinguished organisms that interact with their environment as a unit
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Habitat
The place where a plant pr animal lives
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Population
All the members of the same species living in an area
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Community
All different populations in an area
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Abiotic factor
Non-living factors
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Biotic factor
Living factors
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Climatic factors
Refer to weather over a long period of time
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Edaphic factor
Relate to soil
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Producers
Organisms that carry out photosynthesis
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Flora
All the plants in an ecosystem
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Consumers
Organisms that take in food from another organism
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Fauna
All the animals in an ecosystem
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Decomposer
Organism that feed in dead organic matter
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Food chain
A sequence of organisma in which each one is easten by the next member in the chain
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Trophic level
A feeding stage in a food chain
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Food web
Consists of two or more inter-linked food chains
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Pyramid of numbers
Represents the nunber of organisms at each trophic level in a food chain
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Niche
The functional role it plays in the community
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Nutrient recycling
The way in which elements such as carbon and nitrogen are exchanged between the living and non-living components of an ecosystem
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Nitrogen fixation
The conversion of nitrogrn gas into ammonia, ammonium or nitrate
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Nitrification
The conversion of ammonia and ammonium compounds to nitrite and then nitrate
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Denitrification
The conversion of nitrates to nitrogen gas
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Pollution
Any harmful additon to the environment
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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.
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Competition
When organisms actively struggle for a resource that is in short supply
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Intra-specific competition
Takes place between members or the same species
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Inter-specific competition
Occurs between membere of different species
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Contest competition
There is an active physical contedt between two individual organisms
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Scramble competition
All the competing individuals gets some of the resources
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Predation
The catching, killing and eating of another organism
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Predator
An organism that catches, kills and eats another organism
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Prey
The organism that is eaten by the predator
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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
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Symbiosis
Ooccurs when two organisms of different species live in close association and at least one of them benefits
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Qualitative study
Records the presence and absence of organisms
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Quantitative study
Records the number of organisms that are present
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Adaptation
Any alteration that improves an organisms chances of survival and reproduction
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Key
Naming organisms by answering a seriee if questions with alternative answers
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Percentage cover
An estimate of the amount of ground in a quadrat covered by each species
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Frequency
The chance of finding a named species with any one throw of a quadrat
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Protoplasm
All the living parts of a cell
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Cytoplasm
The living materials in a cell outside the nucleus
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Chromatin
The name given to chromosomes they are elongated and not dividing
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Prokaryotic
Do not have a nucleus or membrane enclosed cell organelles
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Eukaryotic
Have a nucleus and cell organelles all of which are enclosed by membranes
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Tissue
A group of similar cells that are modified to carry out the same function
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Tissue culture
The growth of cells in or on a sterile nutrient medium outside an organism
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Organ
A structure composed of a number of tissues that work together to carry out one or more functions
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Solar energy
Energy from the sun
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Cellular energy
The energy stored in the bonds of biomolecules
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Catalyst
A substance that speeds up a reaction without itself being used up in the reaction
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Enzyme
Proteins that speed up a reaction without being used up in the reaction
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Substrate
The substance with which an enzyme reactd
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Product
The substancd the enzyme forms
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Denatured enzyme
An enzyme that has lost its shape and can no longer function
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Bioprocessing
The use of enzyme-controlled reactions to produce a product
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Bioreactor
A vessel or container in which living cells or their products are used to make a product
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Immobilised enzyme
Enzymes that are attached or fixed to each other or to an inert material
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Enzyme specificity
Each enzyme will react with only one particular substrate
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Optimum pH
The pH value at which the enzyme works best
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Photolysis
The splitting of water by light
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Aerobic respiration
The controlled release if energy from food using oxygen
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Anaerobic respiration
The controlled release of energy from food without using oxygen
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Fermentation
Another name for anaerobic respiration
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Biotechnology
The use of living things or their components to manufacture useful products or to carry out useful reactions
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Glycolysis
The conversion of glucose into two molecules of pyruvic acid
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Selectively permeable
Allows some but not all molecules to pass through
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Diffusion
The spreading out of molesioes from a region if high concentration to a region if low concentration across a selectively permeable membrane
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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
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Turgor
The outward pressure of the cytoplasm and vacuole against the cell wall of the plant
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Cell continuity
Cells develop from pre-existing cells
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Chromosomes
Coiled threads of DNA and protein that become visible in the nucleus at cell division
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Gene
A section of DNA that contains the instructions for the formation of a protein
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Haploid cell
Has one set of chromosomes
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Diploid
Has two sets of chromosomes
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Homologous pair
Two chromosomes of similar size with the same sequence of genes
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Cell cycle
The changes that take place in a cell during the period between one cell division and the next
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Interphase
The phase in the cell cycle when the cell is not dividing
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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
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Meiosis
A form of nuclear division in which the four daughter nuclei contain half the chromosome number of the parent nucleus
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Centromere
The point at which the chromosomes are attached in a double strandd chromosome
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Heredity
The passing on of features from parents to offpsring by means of genes
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Gene expression
The way in which the genetic information in a gene is decoded in the cell and used to make a protein
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Characteristics
Traits or features that are inherited genetically
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Non-coding DNA
DNA that does not cause the production of a protein
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Genetic code
The sequence of baaes in DNA that provide the instructions for a cell to form a protein
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Triplet/Codon
A sequence of three bases in DNA that act as a code for an amino acid
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Triplet/Codon
A sequence of three bases in DNA that act as a code for an amino acid
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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
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Forensic medicine
The way in which medical knowledge is used in legal situations
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Genetic screening
Testing DNA for the presence or absenfe of a particular gene or an altered gene
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Transcription
The copying of a sequence of genetic bases in DNA onto messenger RNA
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Translation
The conversion of a sequence of genetic bases on messenger RNA into a sequence of amino acids
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Purine
Adenine and Guanine
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Pyrimidine
Thymine and Cytosine
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Anticodon
A sequence of three basss in tRNA that are complementary to a sequence of three bases on mRNA
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Gametes
Haploid cells that are capable of fusion
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Fertilisation
The union of 2 gametes to form a single cell called a zygote
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Dominant
The allele that prevents the recessive allele from being expressed
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Recessive
The allele that is prevented from being expressed by a dominant allele
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Allele
Different forms of the same gene
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Locus
The position of a gene on a chromosome
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Genotype
The genetic makeup of an organism
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Phenotype
The physical make-up of an organism
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Progeny
Refers to offspring that are produced
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Homozygous
2 alleles are identical
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Heterozygous
The alleles are different
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Punnett square
The grid used to show the ratio of the genotypes of the progeny in a genetic cross
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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
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Pedigree
A diagram showing the genetic history of a group of related individuals
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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.
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Monohybrid cross
The study of a single characteristic
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Dihybrid cross
The study of two characteristics
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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
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Linkage
Genes are located on the same chromosome
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Sex Linkage
A characteristic is controlled by a gene on a sex chromosome
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Classification
Placing objects into group based on similar characteristics
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Taxonomy
The science of classifying organisms
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Taxonomy
The science of classifying organisms
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Species
A group of similar organisms that are capable of naturally interbreeding with each other to produce fertile offspring
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Variation
In a group of successfully interbreeding organisms the individual members show different characteristics
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Acquired variation
Not inhertied but are learned or developed during life
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Inherited variation
Controlled by genes
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Mutations
A spontaneous change in the amount or structure of DNA
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Mutagens
Agents that cause mutations
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Gene mutation
A change in a single gene
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Chromosome mutation
A large change in the structure or number of one or more chromosomes
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Evolution
The way in which living things change genetically to produce new forms of life over long periods of time
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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
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Speciation
The production of a new species as a result of evolution
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Fossil
The remains of something that lived a long time ago
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Genetic engineering
The artificial manipulation or alteration of a gene
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Isolation
The removal of a chromosome from the human cell and the plasmid DNA from the bacterium
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Ligation
The joining of two sections of DNA to form a single strand
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Transformation
The uptake of DNA into a cell
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Cloning
The production of identical copies of the bacterium
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Expression
The formation of the product by the organism with the recombinant DNA
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Cell
The smallest unit of a living thing
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Autotrophic
An organism that makes it's own food
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Chemosynthetic
The production of food using energy released from chemical reaction
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Heterotrophic
An organism takes in food made by other organisms
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Saprophytic
Organisms that take in food from dead organic matter
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Parasites
Organisms that take in food from a live host and usually cause it harm
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Pathogenic bacteria
Bacteria that cause disease
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Antibiotics
Chemicals produced by micro-organisms that stop the growth of, kill other micro-organisms without damaging human tissues
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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
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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
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Hypha
A tube or filament in a fungus
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Mycelium
A visible mass of hyphae
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Obligate parasite
Can only take it's from a live host
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Facultative parasite
Can get its food from a live or a dead host
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Facultative parasite
Can get its food from a live or a dead host
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Sporulation
The process of making spores
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Aseptic/asepsis
Measures are taken to exclude unwanted micro-organisms
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Sterile
All micro-organisms are destroyed
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Meristem
Plant tissue capable of mitosis
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Herbaceous plant
Do not contain wood/aligning
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Woody plant
Contain wood or lignin
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Node
The point on a stem at which a leaf is attached
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Internode
The region on a stem between two nodes
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Bud
A potential growth point that may develop into a shoot a left or a flower
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Bud
A potential growth point that may develop into a shoot a left or a flower
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Venation
The pattern of veins in a leaf
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Lignin
Strengthening material found in some plant cell walls
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Cotyledon
A seed leaf
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Transpiration
The loss of water by evaporation from the leaves and other aerial parts of a plant
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Lenticels
Openings in the stems of plants that allow gas exchange
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Cohesion
The sticking of similar molecules to each other
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Adhesion
When different molecules stick together
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Plasma
The liquid part of the blood
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Serum
Plasma from which the clotting proteins have been removed
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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
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Closed circulatory system
Blood remains in a continuous system of blood vessels e.g humans
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Blood pressure
The force the blood exerts against the wall of a blood vessel
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Blood pressure
The force the blood exerts against the wall of a blood vessel
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Valves
Control the direction of the blood flow
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Portal system
Blood pathway that begins and ends in capillaries and do not connect directly to the heart
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Diastole
When the heart chambers relax
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Systole
When the heart chambers contract
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Pulse
The alternate expansion and contraction of the arteries
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Herbivores
Animals that feed mainly on plants e.g sheep
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Carnivores
Animals that feed mainly on animals e.g dogs
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Omnivores
Animals that feed on plants and animals e.g badgers
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Digestion
The physical and chemical breakdown of food
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Peristalsis
A wave of muscular action in the walls of the alimentary canal that moves the contents along
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Balanced diet
Contains all the necessary food types in the central proportion
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Homeostasis
The ability of an organism to maintain a constant internal environment
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Pharynx
The throat
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Larynx
The voice box
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Inhalation
Breathing in
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Exhalation
Breathing out
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Ecotherms
Gain or lose hest from or to their external environment
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Endotherm
Generate their own heat from metabolic reactions
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Filtration
Water and small molecules pass under high pressure from the blood into the nephron
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Reabsportion
Molecules pass from the nephron back into the blood
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Active transport
Energy in the form ATP is used to move molecules often against a concentration gradient
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Secretion
Some substances pass from the blood into the nephron
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Osteoclast
Bone digesting cell
228
Joint
Where two or more bones meet
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Synovial fluid
Produced in movable joints to lubricate and reduce friction
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Ligaments
String, fibrous slightly elastic tissues that connect bone to bone
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Tendons
Strong, flexible, inelastic fibres that connect muscle to bone
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Tendons
Strong, flexible, inelastic fibres that connect muscle to bone
233
Antagonistic pair
Tow muscles that have opposite effects to each other
234
Pathogen
An organism that cause disease
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Immunity
The ability to resist infections
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General defence system
Acts as a barrier to all pathogens attempting to gain entry to the human body
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Specific defence system
Attacks a particular pathogen
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Antigen
A foreign molecule that stimulates the production of antibodies
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Antibody
A protein produced by white blood cells in the response to a specific antigen
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Induced immunity
The ability to resist disease caused by specific pathogens by the production of antibodies
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Active immunity
The production of a person's own antibodies in response to a foreign antigen that enters the body
242
Natural active immunity
Occurs when a pathogen enters the body in the normal way
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Artificial active immunity
When a pathogen is medically introduced into the body
244
Vaccine
Non disease causing dose of a pathogen which triggers the production of antibodies
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Passive immunity
When individual are given antibodies that were formed by another organism
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Natural passive immunity
When a child gets antibodies from its mother
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Artificial passive immunity
When a person is given an injection containing antibodies made by another organism
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Vaccination
The administration of a non-disease causing dose of a pathogen to stimulate the production of antibodies.
249
Immunization
When we produced or are injected with antibodies against a pathogen
250
Plasma B cells
Produce antibodies
251
Memory B cells
Survive years after the infection is eliminated and can make the specific antibody if the same infection later enters the body
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Helper T cells
Stimulate B cells and Killer T cells
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Killer T cells
Destroy abnormal human body cells
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Suppressor T cells
Inhibit the immune response
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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
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Bacteriophage
A virus that infects bacteria
257
Gamete
Haploid cells that are capable of fusion
258
Pollination
The transfer if pollen from an anther to a stigma of a flower from the same species
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Self pollination
Involves the transfer of a pollen from an anther to a stigma on the same plant
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Cross pollination
Involves the transfer of a pollen from an anther to a stigma on a different plant
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Fertilisation
The union of the Male and female gametes to form a diploid zygote
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Radical
The part of the plant embryo that develop into the root
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Plumule
The part of the plant embryo that develops into the shoot
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Non-endospermic seed
Has no endosperm when fully formed
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Endospermic seed
Contains some endosperm when fully formed
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Fruit
Developed ovary
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Dispersal
The transfer of a seed or fruit away from the parent plant
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Germination
The regrowth of the embryo after a period of dormancy if the environmental conditions are suitable
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Vegetative propagation
Asexual reproduction in plants it only involves one parent and can be artificial or natural
270
Natural vegetative propagation
Involves forming new plants from a stem, roots leaf or bud
271
Runners
Horizontal stems that runs above ground and from which new plants grow
272
Root tubers
A swollen underground root that remains dormant during winter and from which new plants grow
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Bulbs
Modified bud
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Cutting
A portion of a plant that is removed from the parent plant and grown into a new Independent plant
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Grafting
The joining and uniting of part of one plant with a second part.
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Layering
The growth of a new plant from a stem that is still attached to the parent plant
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Micro propagation
The growth of plants from small pieces of tissue under sterile conditions on a specifically selected medium
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Gonad
An organ that produces sex cells in animals
279
Puberty
Beginning of sexual maturity
280
Secondary sexual characteristics
Features that distinguish males from females apart from the sex organs themselves
281
Ovulation
The release of an egg from the ovary
282
Menstrual cycle
A series of events that occur every 28 days on average in the female if fertilisation has not taken place
283
Menstruation
The discharge of the lining of the uterus and the in infertilised egg
284
Insemination
The release of the semen in the vagina just outside the cervix
285
Implantation
The embedding of the fertilised egg into the lining of the uterus
286
In vitro fertilization
Removing eggs from an ovary and fertilizing them outside of the body
287
Morula
Solid ball of cells formed from a zygote by mitosis
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Blastocyst
A hollow ball of cells formed from a morula
289
Germ layers
Basic layers of cells in the blastocyst from which all adult tissue and organs will form
290
Birth control
Methods taken to limit the number of children that are born
291
Contraception
The deliberate prevention of fertilisation or pregnancy
