WJEC GCSE Definitions Unit 2

flowering plants

plants that produce flowers

non-flowering plants

plants that don't produce flowers

vertebrates

animals with a backbone

invertebrates

animals without a backbone

morphological features

the shape and structure of the body

scientific name

a universal name for organisms

morphological adaptations

structural adaptations of the organisms either internal or external

interspecific competition

competition between different species

intraspecific competition

competition between members of the same species

biodiversity

the variety or number of different species in a given area

alien species

a species that is introduced to an area that it would not usually be found in order to control specific pests

SSSI

sites of specific scientific interest where are designated areas that are protected

seed/banks

a place where seeds/sperm are stored to preserve genetic diversity for the future

CITES

convention on international trade in endangered species

biological control

the use of living organisms to reduce the population of a pest species

quadrat

a square frame is used to sample a measured area by being placed randomly and the individuals inside are counted and recorded and then used to calculate the population in an area

transect

a set of samples taken along a set line to measure how population changes along a gradient

capture recapture method

used to estimate the population by capturing and marking species and then taking a second sample after some time and using the marked species to calculate the estimated population

chromosome

a long coiled section of DNA usually found in pairs that contains genes

gene

a section of DNA found in chromosomes that controls a particular characteristic

mitosis

the normal form of cell division that is used to produce cells for growth and repair, each division produces two genetically identical cells with the same number of chromosomes as the mother cell

meiosis

this type of cell division produces gametes, each division produces four genetically different cells with half the number of chromosomes as the mother cell

differentiation

when cells multiply and develop to be specialised for a particular purpose

cancer

a disease that is as a result of cells with uncontrolled growth where the cells are multiplying too frequently because of a fault

stem cells

undifferentiated cells that have the capacity yo develop into specialised cells, these can be either taken from an adult, an embryo or the meristem of a plant

gamete

the proper name for the egg and sperm cells or sex cells

allele

a different form of the same gene

amino acids

small molecules that make up a protein

complementary base pairings

describes how the bases in DNA pair up A+T G+C

cystic fibrosis

a genetic disorder caused by homozygous recessive alleles that results in thicker mucus and therefore a mucus build up in the lungs

dominant

the character which shows in the heterozygote

recessive

the character which is masked in the heterozygote

F1 generation

the first generation of a genetic cross as a result of two organisms interbreeding

F2 generation

the second generation of a genetic cross as a result of two organisms from the F1 generation interbreeding

double helix

the shape used to describe the structure of DNA

DNA profiling

the process that involves cutting DNA into short pieces which are then separated into bands and used to show the similarity between two samples

selfing

self fertilisation

genotype

the genetic makeup of an individual

phenotype

the way the gene is seen or expressed, what the individual looks like

heterozygous

an individual who has two different alleles of a particular gene

homozygous

an individual who has two identical alleles

male genotype

XY

female genotype

XX

genetic modification

where a gene from one species can be transfered to another species

continuous variation

where the individual can be at any point along a scale, usually a bell shaped curve graph, usually controlled by more than one gene

discontinuous variation

where the individual is in a distinct category, usually displayed in a bar chart, usually controlled by a single gene