Question

Which statement about the genotypes of organisms is correct?
A. Dominant alleles are only found in homozygotes
B. One recessive allele always causes a recessive phenotype.
C. Recessive phenotypes must be homozygous
D. The dominant phenotype must be heterozygous

Answer 1

C - Recessive phenotypes must be homozygous

Explanation:

• Two alleles for a given gene are expressed in a diploid organism and interact to produce physical characteristics.
• The genotype is the genetic makeup of an organism, which comprises both physically visible and non-expressed alleles.
• A dominant phenotype is defined as having only one copy of a dominant allele, which can come from only one parent.
• A person must have two copies of a recessive allele (homozygous), one from each parent, to have a recessive phenotype.
• A person with one dominant and one recessive allele for a gene is said to have a dominant phenotype.

Answer 2

Answer:

c) Recessive phenotypes must be homozygous is the correct statement bout the genotypes of organisms.

Explanation:

• Recessive alleles only manifest their phenotype when an organism possesses two identical copies of the recessive gene, indicating that it is homozygous for the recessive allele. So, option (c) is the correct statement.
• There is no dominant allele in homozygous recessive people, therefore the phenotype is solely determined by the recessive alleles.
• To have a recessive phenotype, a person must have two copies of a recessive allele, one from each parent. The dominant phenotype is defined as an individual who has one dominant and one recessive allele for a gene.
• The dominant allele might be homozygous or heterozygous in the genotype of an organism having a dominant phenotype.