Cystic fibrosis is a recessive genetic disorder caused by a mutation of the CTRF gene. The disease is characterized by excessive mucus production along the respiratory and digestive tracts in addition to other symptoms. Cystic fibrosis is a progressive disorder that is most associated with chronic respiratory disease.
Sara and Anthony found out that they are both carriers of the disorder, but neither have the disease. What are the chances their child will be born with cystic fibrosis?
A. 0:4
B. 4:4
C. 1:4
D. 1:2
the gene is recessive; so the carriers have a normal CTRF gene, coupled with a recessive
the possible genotypes of the offspring are
... CC, Cr, rC, rr
... out of four possibilities
... one normal
... two carriers
... one with the disorder
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1:4, Your welcome;)
Cystic fibrosis is a recessive genetic disorder caused by a mutation of the CTRF gene. The disease is characterized by excessive mucus production along the respiratory and digestive tracts in addition to other symptoms. Cystic fibrosis is a progressive disorder that is most associated with chronic respiratory disease.
Sara and Anthony found out that they are both carriers of the disorder, but neither have the disease. What are the chances their child will be born with cystic fibrosis?
To determine the chances of their child being born with cystic fibrosis, we need to understand the inheritance pattern of the disorder. Cystic fibrosis is an autosomal recessive disorder, which means that both parents must be carriers of the mutated gene for the child to have the disease.
Since Sara and Anthony are both carriers of the cystic fibrosis gene but do not have the disease themselves, they each have one functioning copy of the CTRF gene and one mutated copy. When they have a child, each parent will pass on one copy of their gene to the child.
The chances of their child inheriting the mutated gene from both parents would be the probability of receiving one mutated gene from Sara multiplied by the probability of receiving one mutated gene from Anthony. Since these events are independent, we can use the multiplication rule of probability.
According to the multiplication rule, the probability of two independent events occurring is the product of their individual probabilities.
Each parent has a 50% chance of passing on the mutated gene, so the probability of their child inheriting the mutated gene from Sara is 1/2 or 0.5, and the probability of their child inheriting the mutated gene from Anthony is also 1/2 or 0.5.
To calculate the probability of both events happening, we multiply the individual probabilities: 0.5 x 0.5 = 0.25 or 1/4.
Therefore, the chances that their child will be born with cystic fibrosis is 1 in 4, which can be represented as a ratio of 1:4.
The correct answer is C. 1:4.