Genetics: key words

• alleles- different versions of the same gene which are sometimes called variants. new alleles are produced through mutation
• dominant allele- version of a gene whose characteristics is always expressed if present in the genotype.
• genetic cross- a technique used to show the possible characteristics of an offspring.
• gene- a sequence of DNA bases that code for a protein
• genome- all the genetic material present in organisms
• genotype- combination of genes inherited from parents, not necessarily what will be shown by phenotype
• heterozygous- organism who has different alleles of genes
• Homozygous- organisms who had two copies of the same allele
• phenotype- characteristics which are observed in an organism
• Punnett square - diagram used to show the possible genetic makeup of offspring, based on a mother's and father's genes. a type of genetic diagram
• recessive allele- version of a gene whose characteristic is only expressed if two copies are present in the genotype