How environments affect phenotypic expression

• Genome: the complete set of DNA of an organism and the mapping of gene arrangement.
• Genotype: the set of genes in the DNA responsible for a particular phenotypic trait.
• Phenotype: the physical expression of that trait, as a protein or physically observable characteristic.
• Gene: The structural and functional unit of inheritance; a sequence of DNA carried on chromosomes and processed to produce a polypeptide.
• Allele: alternative forms of a gene such as A, B, O blood types or T and t as height alleles in plants.
• Dominant Allele: the allele that is expressed when it is present in a genotype; often represented by a capital letter.
• Recessive Allele: the form of allele that is only expressed when it is homozygous (two of the recessive alleles are present in the genotype); often represented by a lowercase letter.
• Homozygous: alleles are homozygous when they are both the same.
• Heterozygous: alleles are heterozygous when they are both different.
• Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product (protein).
• Phenotype, can be influenced by the environment including the womb, diet, climate, and disease.
• Phenotypes that are not influenced by the environment include

  • Blood type
  • Cystic Fibrosis
  • Hemophilia
• Phenotypes that can be influenced by the environment include

  • Breast Cancer
  • Schizophrenia
  • Hypertension
• Blood types - represented in humans in the phenotypes A, B, AB, or O types of blood. There is no evidence of any environmental impact on blood type; therefore this phenotype is totally inherited.
• Flowers - Flower color is determined by the pH of the soil. pH effects the availability of other ions in the soil and these ions are responsible for the color change.