I think the correct answer from the choices listed above is the last option. The control group to be used to test the hypothesis would be the swallows with average-length tails. A control group <span>is defined as the </span>group<span> in an experiment or study that does not receive treatment by the researchers.</span>
Complete question:
Question: When crossing two individuals, the offspring display only one of the two traits found in parents. Which principle of Mendelian genetics is supported by this observation?
a) segregation
b) independent assortment
c) dominance and recessiveness
d) allele frequency
Answer:
c) dominance and recessiveness
Explanation:
According to Mendel's principle of dominance and recessiveness, the alleles of one gene may be dominant or recessive in nature. When present together, only the dominant allele is able to express itself. Therefore, a hybrid individual for a gene would express only the dominant phenotype. In the given cross, the progeny express only one of the two traits found in the parents. This means that the progeny is heterozygous for the trait and is expressing the dominant trait. The recessive trait is not expressed due to the presence of the allele for the dominant trait.
Answer:
CFTR protein facilitates the transport of chloride ions and water across the cells. Genetic defect in the CFTR gene results in defective protein synthesis. This defect in CFTR protein disrupts the chloride and water channel across the cell. The CFTR protein acts as a channel across the cell membranes which are specialized to produce mucus, sweat, tears etc. Failure of transport channel will result in symptoms like secretion of thick mucus. This mucus can obstruct the airflow and glands resulting in symptoms of cystic fibrosis.
