Cystic fibrosis is a genetic disorder. It is a recessive trait that is determined by two alleles. Suppose two parents each carry at least one recessive allele, but neither of them has cystic fibrosis. Which statement reflects the likelihood of a child of these parents having cystic fibrosis? The child cannot have the disease because only the dominant alleles will be passed on. The child will have the disease because only recessive alleles will be passed on. The child may or may not have the disease because a recessive gene from each parent may be passed on. The child may or may not have the disease because the disease does not depend on the alleles of the parents.
Added by Troy B.
Step 1
We can represent the dominant allele as "A" and the recessive allele as "a". So, both parents have the genotype Aa. Now, let's consider the possible genotypes of their offspring using a Punnett square: ``` A | a --------- A | AA | Aa --------- a | Aa | Show more…
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Cystic fibrosis is a genetic disease that affects the lungs and other organs. Affected individuals are prone to infection because they can't produce normal mucus that helps the lungs clear bacteria. People with the disease have two mutant copies of the cystic fibrosis gene (CFTR), while people with a single mutant copy (heterozygous of CFTR) don't have the disease but are carriers. What is the mode of inheritance (dominant or recessive) of cystic fibrosis? What proportion of people have the disease?
Adi S.
Cystic fibrosis is a recessive genetic disorder that affects the respiratory and digestive systems. Alex was recently diagnosed with cystic fibrosis. He had symptoms such as coughing and an increased appetite with no weight gain. Neither of his parents show symptoms of the disease. Use C to represent the normal allele and c to represent the recessive cystic fibrosis allele. What are the allele combinations of the parents? Hetero The parents who do not show symptoms of cystic fibrosis would be considered carriers of the disease. What is the allele combination of the affected individual? What are the chances that any future children from the same parents will not inherit cystic fibrosis?
Cystic fibrosis is a genetic disease. People with CF have inherited two copies of the defective CF gene -- one copy from each parent. Both parents must have at least one copy of the defective gene. People with only one copy of the defective CF gene are called carriers, but they do not have the disease. Each time two CF carriers have a child, the chances are: 25 percent (1 in 4) the child will have CF 50 percent (1 in 2) the child will be a carrier but will not have CF 25 percent (1 in 4) the child will not be a carrier and will not have CF 1. In a random sample of 10 families in which both parents are CF carriers and have one child, the probability that we observe at least two children who is a carrier but do not have CF is [prob1]. 2. The expected number of families with a child who is not a carrier and does not have CF is [prob2].
Sri K.
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