Topic 4- genetics, biodiversity and classification Flashcards
What is a gene?
a base sequence of DNA that codes for the amino acid sequence of a polypeptide and functional RNA
What is meant by the term ‘degenerate code’?
more than one codon codes for a single amino acid
Why is genetic code described as ‘universal’?
In all organisms, the same codon codes for the same amino acid.
Describe what is meant by ‘non-overlapping’ code
each base is read once in the codon that is part of it
Within a gene, what is an exon?
A base sequence in a gene that codes for a polypeptide
Within a gene, what is an intron?
A sequence in a gene that is non-coding
Define the term ‘genome’.
The complete or full set of genes or genetic information in a cell.
Define the term ‘proteome’.
the full range of protein a cell is able to produce
What is a gene mutation?
A gene mutation involves a change in the base sequence of chromosomes
Define ‘homologous chromosomes’.
two chromosomes that carry the same set of genetic information
What is a gene pool?
all the alleles in a population
What is meant by the term ‘directional selection’?
Where one extreme of a continuous phenotype is selected at the expense of the other phenotypes.
in what kind of classification are organisms grouped together according to evolutionary relationships or common ancestry?
Phylogenetic classification.
Define the term ‘biodiversity’
Biodiversity refers to the number of species, variation within a species and variation of cell types within a single multicellular organism.
What is species diversity?
Species diversity defines the number of species or different species in a community
