Definitions Genetics

Created by

Evie Robertshaw

Cards (48)

What is an adaptation 
A feature of an organism that increases its chance of survival in its environment
What is an allele 
A version of a gene
What is an anticodon 
A sequence of 3 nucleotide bases at one end of the tRNA molecule that is specific to mRNA codon
What is artificial classification 
A type of classification that divides organisms into groups based on analogous characteristics such as leaf shape, number of legs and type of wing.
What is a binomial system 
A universal system of naming organisms that consists of 2 parts: the generic name and the specific name e.g Homo sapiens
What is biodiversity  
The variety of genes, species, habitats within a particular area
What is a proteome? 
The complete set of proteins expressed by a genome.
What is a chromatid 
One strand of a replicated chromosome
What is a chromosome
A structure consisting of a long, coiled molecule of DNA and its associated proteins, by which genetic information is passed from generation to generation
What is a chromosome mutation
A change to the number or structure of chromosomes that can occur spontaneously
What is classification 
The organisation of organisms into groups. There are 2 types of classification: artificial and phylogenetic
What is a codon 
A sequence of 3 bases on mRNA that codes for a specific amino acid
What is courtship 
The behaviour of which members of a species select reproductive partners. It enables organisms to recognise their own species, identify a mate which a capacity to breed, form a pair bond, synchronise mating and become able to breed themselves
What is crossing over 
The process in Meiosis 1 in which homologous chromosomes pair up, their chromatids wrap around one another and their alleles are exchanged at equivalent portions of chromatids. This creates genetic variation.
What does degenerate mean? 
A feature of genetic code where more than one triplet can code for a particular amino acid
What is a deletion 
A form of gene mutation in which one or more nucleotide bases are removed from the DNA sequence. This may change all amino acids in a sequence, rendering the protein non functional
What is directional selection 
A type of selection that favours individuals that differ in one direction from the population mean. This changes the traits of the population
What is ecosystem diversity
A measure of the range of different habitats in a particular area
Explain eukaryotic DNA 
Linear molecules of DNA which, together with histones form chromosomes. DNA in the mitochondria and chloroplasts of eukaryotic cells is circular and does not have associated proteins.
What is an exon
A sequence of DNA that codes for an amino acid sequence
What is a gene 
A length of DNA on a chromosome that codes for the production of one or more polypeptide chains and functional RNA.
What is a gene mutation
A change to at least one nucleotide base in DNA or the arrangement of bases. Gene mutations occur spontaneously during DNA replication
What is genetic diversity
The number of different alleles in a population. Genetic diversity between organisms can be investigated by comparing observable characteristics, DNA and mRNA base sequences and amino acid sequences.
What is a genome
The entire set of genes in a cell
what are homologous chromosomes
A chromosome pair, one paternal and one maternal with the same gene loci.
What is independent segregation?
Independent segregation refers to the random assortment of homologous chromosomes during meiosis, resulting in the independent distribution of alleles into gametes.
What is an intron?
A non coding sequence of DNA
What is a loci?
The position of gene on a chromosome
What is meiosis? 
A type of cell division that produces 4 genetically different daughter cells with a haploid number of chromosomes
What is mRNA 
A type of RNA that carries genetic information from the nucleus to the ribosomes for protein synthesis.
What is mitosis 
A form of cell division that produces two genetically identical diploid daughter cells
What is a mutagen agent?
An agent which increases the rate of gene mutations above normal level
What is natural selection? 
The process by which the frequency of advantageous alleles gradually increases in a populations gene pool over time
What is non-disjunction 
A change in the number of chromosomes due to the failure of homologous chromosomes to separate during meiosis. This may result in a gamete with one more or one less chromosome
What does non-overlapping mean
A feature of genetic code each base in a sequence is read once and is only part of one triplet
What is phylogenetic classification
A type of classification that divides organisms into groups based on evolutionary relationships and homologous characteristics. It uses a hierarchy in which smaller groups are contained within larger groups with no group overlap
What is phylogeny 
The evolutionary relationships between individuals and groups of organisms
Explain prokaryotic DNA 
Circular pieces of DNA that do not have associated proteins
What does RNA polymerase mean 
An enzyme that moves along the DNA template strand and joins adjacent nucleotides to form pre mRNA
What is species diversity 
A measure of the number of different species and the abundance of individuals in each of these species within a community.