Answer:
Genes are portions of DNA that contains information to encode proteins
Alleles are different forms of one gene
Chromosomes are closed circular DNA molecules that contain the genetic material of an organism
Explanation:
Genes can be defined as regions of DNA which are transcribed to produce messenger RNAs (mRNAs) by a process known as transcription. Subsequently, these mRNAs are translated into proteins. In diploid organisms, each gene contains two different forms called alleles. A chromosome is a long DNA molecule that contains part or even the entire genetic material of an organism. In diploid organisms, one chromosome contains one allele (inherited from one parent), while its homologous chromosome pair contains another allele of the same gene (inherited from the other parent).