Genetics Flashcards
Species
Organisms capable of interbreeding and producing fertile offspring
Heredity
The passing on of traits from parent to offspring by means of genes
Gene Expression
The process of using the information on the gene to make the protein
Gene
A unit of DNA which codes for the production of a specific protein
DNA profiling
Extracting DNA and making a unique pattern of bands from the DNA of a person which can then be used to distinguish that DNA from another person’s DNA
Coding DNA
The part of the chromosome which carries the information to make a protein
Genetic screening
Testing an individual for the presence or absence of a particular allele
Gamete
A haploid sex cell
Fertilisation
The fusion of two haploid gametes to form a diploid zygote
Allele
Alternative form of the same gene
Homozygous
Having two identical alleles for a trait, e.g. TT
Heterozygous
Having different alleles for a trait, e.g. Tt
Genotype
The genetic make up of an organism
Phenotype
The physical appearance of the organism
The genotype + the environment
Dominance
When one allele masks the expression of the other
Expressed in the phenotype
Recessive
An allele whose expression is masked by the dominant
Incomplete dominance
When neither allele masks the expression of the other
Mendel’s First Law
Law of Segregation
Traits are controlled by pair of alleles with separate at gamete formation
Each gamete carries only one allele for each trait
Mendel’s Second Law
Law of Independent Assortment
During gamete formation, each members of a pair of alleles may combine randomly with either of another pair
Linkage
Genes located on the same chromosome (locus) are said to be linked
Sex linkage
Genes located on the same sex chromosome (X or Y)
Non-nuclear DNA
DNA apart from that found outside the nucleus of the cell that is passed onto the next generation, e.g. mitochondrial DNA is inherited maternally
Non-coding DNA
Junk DNA
The part of the chromosome which does not carry information to make a protein
Transcription
The process of producing mRNA using DNA as a template
Translation
The process of making a protein using the mRNA code as a template
Variation
Different between members of a species
Mutation
Change in the genetic make-up by a change in the structure or number
Genetic engineering
The artificial manipulation or alteration of genes
Evolution
An inheritable change with a species in response to a change in the environment by natural selection over a long period of time, e.g. modern horse
