Describe the meaning of the terms: gene, genetic locus, alleles, phenotype and genotype

A gene is a length of DNA that codes for a particular trait. ( Think of- jeans - they are long items (length) of clothing, what they're made out of determines what they are. This is a key concept of genetics)
The position of a gene on the chromosome is called the genetic locus . (LOCus LOCation)
For each gene there are alternative forms called alleles. (ALleles ALternatives)
The two alleles represent a genotype. This is the genetic make - up of an organism (GENotype -think GENetics)
The actual appearance of the trait represents the phenotype (PHenotype - think PHoto - how it appears)