To determine if a particular plant is homozygous or heterozygous, you would have to test cross with a to make the check.
homozygous recessive
heterozygous dominant
homozygous dominant
purebred

Homozygous recessive

Explanation:

Diploid (2n) organisms possess two alleles for a specific gene in which one of the allele can mask the expression of another in that gene. The allele that masks the expression of the other is said to be the dominant allele while the allele that is masked is the recessive allele.

The genotype of an individual is the genetic make-up while the phenotype is the expressed trait. Since, an allele can mask the expression of another, it is therefore impossible to ascertain the genotype of an organism by merely looking at its phenotype. The organism can either be homozygous (TT) or heterozygous (Tt) for that trait

N.B: T represents dominant allele of the gene coding for height, and t represents the recessive allele of the same gene

To determine whether an organism showcasing a dominant trait is homozygous or heterozygous for a specific allele, a TEST CROSS is conducted by crossing that organism with an organism with homozygous recessive trait.

N.B: An organism can only exhibit recessive traits if the alleles are homozygous ( same recessive alleles).

If all the offsprings of the cross showcase dominant traits, it means the parent organism is homozygous dominant but if any of the offsprings exhibit recessive traits, it means the parent organism is heterozygous dominant.

helicase, i think thats it

that scientist would be robert hooke