Genetic

DNA in prokaryotic cell

Short, linear, no introns and no histones

DNA in eukaryotic cell

Long, circular, contains introns and associated with histones

Locus

Fixed position where a gene occupies

How gene is a code for the production of polypeptide

Base in triplets that determines sequence of amino acid sequence

Degenerate

Same amino acid code for by more than one triplets

Exons

Triplets sequence that codes for polypeptide

Introns

Non coding triplets within the gene

Splicing

Remove introns from pre mRNA to form mRNA

Genome

Complete set of genes in a cell

Proteome

Full range of protein that a cell is able to produce

mRNA

Linear

tRNA

Clover leaf shape

Contain anticodon and amino acid binding site

Phylogenetic classification system

Shows evolutionary relationship

Hierarchy

Smaller groups place within larger groups with no overlap

Taxonomical system

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

Directional selection

Alleles for characteristic of an extreme type in response to environmental change

Stabilising selection

Towards middle of the range when environment isn’t changing

Anatomical adaptation

Structural features

Physiological adaptation

Internal process such as metabolic rate

Behaviour adaptation

eg play dead to escape attack

Genetic diversity

Number of different alleles of genes in a population

Reduce genetic diversity

Generic bottleneck - large drop in population

Founder effect - few organism start a new colony so small number of different alleles is in the initial gene pool

Species richness

Measure of the number of different species in a community

Index of diversity

Relationship between the number of species in a community and the number of individual in each species

Species

Group of organism that are able to produce fertile offspring

Standardise random sampling

Use of quadrant

Gene mutation

Change in base of sequence, result in formation of new allele

Mutagenic agent

Factor that increase the rate of mutation

Non-disjunction

Failure of chromosome to separate properly during meiosis

Homologous pair

Two chromosomes that carry the same gene

Crossing over

Homologous pair of chromosomes form a bivalent

Chiasma form and alleles are exchange to produce new combination of alleles