The number of phenotypes produced for a given trait depends on how many genes control the trait. Anyhow, The distribution of phenotypes for a typical polygenic trait can often be expressed as a bell-shaped curve.
Many traits are controlled by two or more genes and are, therefore, called polygenic traits<span>. Each gene of a polygenic trait often has two or more alleles. As a result, one polygenic trait can have many possible genotypes and phenotypes.</span>
Yes a TT plant and a Tt plant are both tall because for it to be short it has to be tt.
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Closest I found was 'species that is harmed in a symbiotic relationship in which another species benefits - host'