monogenic inheritance

Question 1

what is an allele

Answer 1

different version of the same gene

Question 2

what does heterozygous mean

Answer 2

Hh (dominant and recessive gene)
not true breeding, have different alleles at a particular gene locus on chromosomes

Question 3

what does homozygous mean

Answer 3

true breeding, identical alleles at a gene locus of a homologous chromosomes.

HH (homozygous as the two alleles are the same).