Genetics And Genetic Engineering Flashcards
Genetics
The study of heredity and variation in living organisms
Hereditary characteristics
Transferred by gametes
Genome
The complete set of genes of a particular organism
True breeding
When self pollination occurs and all offspring have the same characteristics of the parent plant.
Alleles
Alternative forms of the same gene
Locus
The specific position a gene occupies on the chromosome
Dominant allele
When one allele of a gene pair can mask another
Recessive allele
The allele that is masked and not visibly expressed in an organism
Mendel’s Law of Dominance
If two alleles are different, only the dominant one will be expressed
Geotype
The composition of the gene pair for a specific trait
Phenotype
The observable characteristics of an organism
Homozygous
When the two alleles for a specific trait are the same
Heterozygous
When the two alleles for a specific trait are different
Mendel’s Law of Segrigation
During meiosis, homologous chromosome pairs separate, so each gamete only receives one allele of a gene
Monohybrid cross
A cross where only one hereditary characteristic is investigated at a time
Complete dominance
When two homozygous plants are crossed, and all the first generation plants share the same dominant characteristics
Sex-linked genes
The genes carried by the gonosomes
Sex-linked disorders (2)
- Red-Green colour blindness
- Haemophilia
Natural selection
The mechanism by which the environment determines which individuals are best suited to survive
Beneficial mutations
The development of new alleles that could favour adaptation to a changing environment
Kinds of gene mutations (3)
- Beneficial mutations
- Neutral mutations
- Harmful mutations
Examples of harmful mutations (2)
- Albinism
- Sickle-cell anaemia
Impact of the Human Genome Project (4)
- Provide a basis for research
- More accurate diagnosis
- Predict the risk of disease
- Reduce costs of medical care
Genetic engineering
The sirect manipulation of the genes in an organism
