Is color blindness a sex-linked abnormality?

Correct Answer: A

Rationale: The correct answer is A: TRUE. Color blindness is indeed a sex-linked abnormality as it is often associated with genes on the X chromosome. Since males have only one X chromosome, they are more likely to inherit color blindness if the gene is present. This makes color blindness more common in males. Choice B (FALSE) is incorrect because color blindness is linked to the X chromosome. Choices C (Sometimes) and D (Always) are incorrect as color blindness is consistently tied to the X chromosome.

Correct Answer: B

Rationale: Rh incompatibility occurs when an Rh-negative woman is carrying an Rh-positive fetus, not the other way around. Therefore, the statement that an Rh-positive woman is carrying an Rh-negative fetus is incorrect. Rh incompatibility can lead to hemolytic disease of the newborn, where maternal antibodies attack the fetal red blood cells. Choice A is incorrect because the statement is false. Choice C is incorrect as Rh incompatibility has a clear cause and effect relationship. Choice D is incorrect as Rh incompatibility can occur, but it depends on the Rh status of the mother and fetus.

Correct Answer: D

Rationale: Sternal retractions in a newborn indicate respiratory distress and require immediate intervention. This finding suggests the newborn is having difficulty breathing and needs prompt attention to ensure adequate oxygenation. Molding, the overlapping of fetal skull bones during birth, is a normal and expected process that does not require intervention. Vernix Caseosa, the protective white substance on the skin, and Acrocyanosis, the bluish discoloration of extremities, are both common and benign findings in newborns that do not necessitate immediate action. Therefore, the healthcare provider should focus on addressing sternal retractions to manage the respiratory distress effectively.

Correct Answer: C

Rationale: Genetics is the branch of biology that focuses on the study of heredity and variation in organisms. Etiology (choice A) deals with the causes of diseases, not heredity. Ecology (choice B) is concerned with the relationships between organisms and their environment, not specifically heredity. Eugenics (choice D) is a controversial field that involves improving the genetic quality of the human population through selective breeding, which is different from the study of heredity itself.

Correct Answer: B

Rationale: The correct answer is B: double helix. DNA is structured as a double helix, resembling a twisted ladder made up of two strands of nucleotides. Choice A, single spiral, is incorrect as DNA is not a single spiral structure. Choice C, sphere, is incorrect as DNA does not form a spherical shape. Choice D, cube, is incorrect as DNA does not have a cubic structure. Understanding the double helix structure of DNA is essential as it allows for the storage and transmission of genetic information in living organisms.