A pregnant woman and her husband are both heterozygous for achondroplastic dwarfism, an autosomal dominant disease. The nurse advises the couple that their unborn child has which of the following probabilities of being of normal stature?

Correct Answer: C

Rationale: In this scenario, the correct answer is C) 75% probability of the child being of normal stature. This is because both parents are heterozygous for achondroplastic dwarfism, an autosomal dominant trait. Being heterozygous means they have one dominant allele (normal stature) and one recessive allele (dwarfism). When both parents are heterozygous, there is a 25% chance of the child inheriting two recessive alleles (dwarfism), a 50% chance of inheriting one dominant and one recessive allele (normal stature but carrier of the dwarfism gene), and a 25% chance of inheriting two dominant alleles (normal stature). Therefore, there is a 75% probability of the child being of normal stature (50% chance of being a carrier and 25% chance of having two dominant alleles). Educationally, this question highlights the principles of Mendelian genetics and the probability of inheritance patterns in autosomal dominant traits. Understanding these concepts is crucial for healthcare professionals to provide accurate genetic counseling and support to individuals and families facing genetic conditions like achondroplastic dwarfism.

Correct Answer: A

Rationale: The correct answer is option A: "Fertility of women who carry the BRCA1 and BRCA2 genes is similar to that of unaffected women." This option is correct because having the BRCA1 and BRCA2 genes does not directly impact a woman's fertility. These genes are associated with an increased risk of breast and ovarian cancer, not infertility. Therefore, women with these genes can still pursue pregnancy and breastfeeding like any other woman. Option B is incorrect because having the BRCA1 and BRCA2 genes does not mean that one should not have children. While there is a risk of passing on these genes to offspring, it is a personal decision whether to have children or not. Option C is also incorrect because it is not recommended to remove ovaries solely based on the presence of BRCA1 and BRCA2 genes. Ovary removal is usually considered as a preventive measure for ovarian cancer in high-risk individuals after thorough counseling and consideration of various factors. Option D is incorrect as well because carrying the BRCA1 and BRCA2 genes does not contraindicate lactation. Breastfeeding is generally safe for women with these genes and does not pose a risk to the baby in this context. In an educational context, it is crucial to provide accurate information to individuals seeking fertility options and counseling related to genetic risks. Understanding the implications of genetic mutations like BRCA1 and BRCA2 on fertility and reproductive choices empowers individuals to make informed decisions about their family planning and healthcare.

Correct Answer: A

Rationale: In this scenario, option A is the correct answer. The statement "If I have a girl, she will be healthy" indicates that the gravid client understands the implications of her carrier status for Duchenne muscular dystrophy. This response shows awareness that being a carrier means her daughters will inherit one X chromosome from her and one from the father, thus not being affected by the disease. Option B is incorrect because it assumes that all her children will be healthy, which is not the case as her sons would have a 50% chance of inheriting the disease. Option C is incorrect as it states that none of her children will be at risk, which is inaccurate since her sons would have a 50% risk of inheriting the disease. Option D is also incorrect as it doesn't address the implications of her carrier status for Duchenne muscular dystrophy. Educationally, this question highlights the importance of understanding genetic inheritance patterns, specifically X-linked recessive diseases like Duchenne muscular dystrophy. It emphasizes the need for individuals to comprehend the risks associated with being a carrier and the potential impact on their offspring, thereby making informed decisions regarding family planning and genetic counseling.

Correct Answer: C

Rationale: The correct answer is C) Show some symptoms of the disease but the severity of the symptoms will be individual. This explanation clarifies the concept of variable expressivity in sickle cell anemia to the mother of a carrier. It is important to understand that while all babies with two recessive sickle cell genes will show some symptoms of the disease, the severity of these symptoms can vary widely among individuals. This variability can range from mild to severe manifestations of the disease. Option A) Develop painful vaso-occlusive crises during their first year of life, is incorrect because not all babies with two recessive sickle cell genes will necessarily experience vaso-occlusive crises in their first year. Option B) Exhibit at least some signs of the disease while in the neonatal nursery, is incorrect because the timing and manifestation of symptoms are not specified in the question, and it's not guaranteed that all babies will exhibit signs while in the neonatal nursery. Option D) Be diagnosed with sickle cell trait but will be healthy and disease-free throughout their lives, is incorrect because having two recessive genes for sickle cell anemia would result in the full-blown disease, not just the carrier trait. Educationally, understanding the concepts of penetrance and expressivity in genetic diseases like sickle cell anemia is crucial for individuals who are carriers or at risk of passing on these conditions to their offspring. By grasping the variability in symptom severity, individuals can better comprehend the potential outcomes and implications for their future children.

Correct Answer: A

Rationale: The correct answer is A) Rises abruptly and then falls 1 or 2 days after menstruation starts. This is because during ovulation, a woman's basal body temperature (BBT) typically rises due to the release of the hormone progesterone after ovulation. This rise in BBT can be used as an indicator of when ovulation has occurred, as it signifies the shift from the follicular phase to the luteal phase of the menstrual cycle. Option B) Falls and remains low for the last half of the cycle is incorrect because the BBT actually rises after ovulation, rather than falling and remaining low. Option C) Is higher during the first half of the cycle than in the last half is incorrect because the BBT is typically higher in the luteal phase (second half of the cycle) due to the presence of progesterone. Option D) Falls just before ovulation and is higher during the last half is also incorrect because the BBT usually rises after ovulation, not falls just before it. Understanding changes in BBT is crucial for couples trying to conceive as it can help pinpoint the most fertile days in a woman's cycle. By tracking BBT along with other fertility signs, individuals can increase their chances of conception. It is essential for individuals dealing with infertility to have a good understanding of their reproductive cycle to optimize their chances of successful conception.