A couple comes into the clinic for genetic counseling. Both parents are heterozygous for sickle cell trait. What is the chance each of their children will have sickle cell anemia?
50%
25%
75%
100%
The Correct Answer is B
The correct answer is b. 25%.
Choice A: 50%
If both parents are heterozygous for the sickle cell trait (carriers), each child has a 50% chance of inheriting one sickle cell gene from one parent and a normal gene from the other parent. This would make the child a carrier of the sickle cell trait, not someone with sickle cell anemia. Therefore, the chance of having sickle cell anemia is not 50%.
Choice B: 25%
When both parents are carriers of the sickle cell trait (heterozygous), there is a 25% chance that their child will inherit two sickle cell genes (one from each parent), resulting in sickle cell anemia. This is because each parent has one normal hemoglobin gene (A) and one sickle cell gene (S). The possible combinations for their children are AA (normal), AS (carrier), SA (carrier), and SS (sickle cell anemia). The probability of the SS combination is 25%.
Choice C: 75%
A 75% chance is not accurate in this scenario. The 75% figure might be mistakenly considered if one were to add the probabilities of being a carrier (50%) and having sickle cell anemia (25%). However, these probabilities are distinct and should not be combined in this manner.
Choice D: 100%
A 100% chance would imply that every child of the couple would have sickle cell anemia, which is not the case. Since each parent is a carrier, there is only a 25% chance for each child to have sickle cell anemia. The remaining 75% of the time, the child will either be a carrier or have normal hemoglobin.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is ["A","C"]
Explanation
The correct answer is a. Vomiting, c. Tachycardia.
Choice A: Vomiting
Vomiting is a common symptom of thyroid storm. Thyroid storm is a life-threatening condition that occurs when the thyroid gland releases a large amount of thyroid hormone in a short period. This sudden surge in thyroid hormone can cause severe metabolic disturbances, leading to symptoms such as vomiting. Vomiting can result from the body’s attempt to cope with the excessive thyroid hormone levels, which can affect the gastrointestinal system.
Choice B: Constipation
Constipation is not typically associated with thyroid storm. In fact, hyperthyroidism, including thyroid storm, usually causes an increase in bowel movements or diarrhea due to the accelerated metabolism. Constipation is more commonly associated with hypothyroidism, where the thyroid gland is underactive and slows down bodily functions.
Choice C: Tachycardia
Tachycardia, or a rapid heart rate, is a hallmark symptom of thyroid storm. The excessive thyroid hormones increase the body’s metabolic rate, leading to an increased demand for oxygen and nutrients. To meet this demand, the heart rate increases significantly, often exceeding 140 beats per minute. This rapid heart rate can be dangerous and requires immediate medical attention.
Choice D: Hypotension
Hypotension, or low blood pressure, is not a typical symptom of thyroid storm. Instead, thyroid storm often causes hypertension (high blood pressure) due to the increased metabolic activity and the body’s heightened demand for oxygen and nutrients. The cardiovascular system responds by increasing blood pressure to ensure adequate blood flow to vital organs.
Correct Answer is C
Explanation
Choice A reason:
Walnuts are a source of protein and contain phenylalanine, an amino acid that individuals with phenylketonuria (PKU) must limit in their diet. While nuts can be a healthy snack for most people, they are not suitable for those with PKU due to their high phenylalanine content. Therefore, walnuts are not the best choice for children with PKU.
Choice B reason:
Cow’s milk is another source of protein and contains significant amounts of phenylalanine. Dairy products, including milk, cheese, and yogurt, are generally high in protein and should be avoided by individuals with PKU. Consuming cow’s milk can lead to elevated levels of phenylalanine in the blood, which can be harmful to children with PKU.
Choice C reason:
Bananas are a fruit that contains very low levels of phenylalanine. Fruits and vegetables are generally safe for individuals with PKU as they are low in protein and phenylalanine. Bananas, in particular, are a good option for children with PKU as they provide essential nutrients without contributing to high phenylalanine levels.
Choice D reason:
Diet soda with aspartame should be avoided by individuals with PKU because aspartame is an artificial sweetener that contains phenylalanine. Consuming products with aspartame can lead to an increase in phenylalanine levels in the blood, which can be harmful to those with PKU. Therefore, diet soda with aspartame is not a suitable choice for children with PKU.
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