science

normal

genetics

the study of variation and inheritance in a gene

gene

A section of DNA that codes for a protein that determines a particular trait

Allele

An alternative version of a gene

DNA

An organised structure of DNA found inside the nucleus of a cell

Homologous chromosome

pairs of chromosomes that are the same length, and carry the same gene at the same loci as each other

genetic code

the base sequence in DNA

genetic variation

differences in the DNA of individuals within a species

mutation

a random permanent change int he base sequence of DNA

point mutation

occurs when a single base or very few bases is changed which affects only a single gene

sexual reproduction

Type of reproduction in which a new offspring is produced by two parents. The offspring produced are genetically different to each other and the parents because it involves combing of DNA from the two parents

asexual reproduction

Type of reproduction in which a new offspring is produced by a single parent. The offspring produced are genetically identical to each other

fertilisation

the ransom joining/combining of a male and a female gamete to form a new zygote/offspring

meiosis

cell division process that produced genetically unique gametes with half the number of chromosomes

population genetics

the field of biology that studies the genetic makeup of populations and how they change overtime

gene pool

All the alleles available to a population

allele frequency

the percentage of each allele in a gene pool

gene flow

the movement of allele between populations/gene pools when individuals migrate between populations

migration

when individuals move from one population to another

genetic drift

change in allele frequencies in a population due to random chance

founder effect

occurs when a small number of individuals from a larger population establishes a new isolated population

bottleneck effect

occurs when there is significant reduction in population size due to an environmental event or human activity

monohybrid inheritance

inheritance of a characteristic controlled by a single gene

dominant

only one copy is required to be present for it to be expressed as the phenotype

recessive

only expressed as the phenotype if both alleles in the genotype are the same recessive allele

genotype

alleles an individuals carried for a gene

phenotype

the physical expression of the genotype

pure breeding

when an individual is homozygous for a trait

selective breeding

Involves choosing parents with particular characteristics to breed together and produce offspring with more desirable characteristics. The aim is to produce a population that is purebred for a certain characteristic.

inbreeding

production of offspring from the mating or breeding of closely related organisms

cloning

Process of creating a genetically identical copy of a DNA, cell. or an organism

transgenesis

process of taking the gene from one organism into the genotype of another organism

DNA sequencing

The process of identifying the exact order of the bases in a DNA strand.

speed

measure of how far an object moves in a given time

vector

a quantity that has magnitude and a direction

scalar

a quantity that has only a magnitude

distance

the total length of the path travelled

displacement

the shortest distance in a straight line from the initial to final position

accesleration

the rate of change of speed

force

a push or a pull on an object

mass

the amount of particles in an object

weight

the gravitational force acting on the object

pressure

the amount of force applied perpendicular to the surface of an object per unit area

gravitational potential energy

the potential energy held by an object due to its position in a gravitational field

kinetic energy

the energy held by a moving mass

work

work is moving on objects a distance

power

rate of energy transferred

electrical conductors

material that does allow current to flow easily

electrical insulators

materials that do not allow current to flow easily

resistance

measure of how much a material reduces the flow of current

current

the rate of flow of electrical charge

voltage

the difference in electrical potential energy per unit charge

mole

The SI unit for the amount of substance, representing 6.022×10²³

pH

the measure of acidity or basic of an aqueous solution

neutralisation reaction

reaction between acid and base that produces salt and water.

precipitation reaction

When two soluble solutions mix together and form a precipitate (insoluble solid)

displacement

occurs between a reactive metal and the ion of a less reactive metal when the metal is placed into a solution containing the metal ions

molecules

Discrete particles made up of non-metal atoms that are held together by covalent bonds

covalent bond

shared pair of electrons between two or more non metal atoms

catalyst

a substance that provides a alternate pathway for a reaction with a lower activation energy

activation energy

the minimum amount of energy a reactant must have in order to react 

collision theory

in order for a chemical reaction to occur two or more reactants must collide with sufficient energy in correct orientation

particle theory

all matter is made of particles and these particles are in constant motion

catalyst

A substance that provides an alternative pathway for a reaction with a lower activation energy. - it increases the ROR without, being used up