Question

Organisms phenotypically similar but genetically different are

• A. Heterozygous
• B. Homozygous
• C. Monozygous
• D. Multizyous

Answer 1

The correct option is A Heterozygous

Alternative forms of a gene are called alleles; individual having two identical alleles are called homozygous while those with two different alleles of a gene are heterozygous. Owing to the presence of the single type of allele; homozygous genotypes are phenotypically similar; for example, a genotype ‘tt” express short phenotype. But both genotypes “TT” and “Tt” express tall phenotype; here “TT” is homozygous, carries the single type of allele, but “Tt” is heterozygous. The term “homozygous” represent being developed from the single zygote. The first division in zygote produce two identical cells that independently develop into two embryos; monozygotic twins are produced. The term “multizygous” represent being developed from individual zygotes. Fertilization of multiple embryos by separate sperms produces multiple zygotes that independently develop into multiple embryos. The correct answer is A.