The correct matching is as follows:
1. Monohybrid cross refers to the breeding of two organisms, which vary in just a single trait.
2. Phenotype refers to the expression of a genetic trait, that is, what the trait looks like.
3. Purebred refers to the trait originating from homozygous genes from the offspring of true breeding.
4. A recessive gene refers to a gene or trait, which is masked when a dominant allele is present.
5. Self-fertilization refers to the procedure when a species that exhibits both male and female gametes makes the fusion of both the identical gametes to produce offspring.