Chromosomes are _____ structures found in cells.

Correct Answer: A

Rationale: Chromosomes are rod-shaped structures that carry genetic information in the form of DNA. They are typically seen as elongated structures when visualized under a microscope. Choice B, circular, is incorrect as chromosomes do not have a circular shape; they are linear. Choice C, cone-shaped, is not accurate as chromosomes do not resemble cones in any way. Choice D, octagonal, is also incorrect as chromosomes do not have an octagonal appearance. Therefore, the correct answer is A, rod-shaped, which accurately describes the shape of chromosomes.

Correct Answer: A

Rationale: During pregnancy, the body increases the production of red blood cells (RBCs) to meet the increased oxygen demands. This physiological response is known as physiological anemia of pregnancy. Therefore, the RBC count is expected to increase during pregnancy. Bilirubin levels may remain relatively stable, fasting blood glucose levels might fluctuate due to gestational diabetes, and blood urea nitrogen (BUN) levels are not typically affected by pregnancy, making them less likely to increase in this scenario. The correct answer is A because an increase in RBC count is a normal physiological adaptation to pregnancy to support the increased oxygen needs of the mother and the growing fetus. Bilirubin, a product of red blood cell breakdown, is more related to liver function and not expected to increase during pregnancy. Fasting blood glucose levels may vary due to gestational diabetes, but it is not a consistent finding in all pregnant individuals. BUN levels are related to kidney function and are not typically impacted by pregnancy, making it an unlikely choice for an expected increase in laboratory values during pregnancy.

Correct Answer: B

Rationale: The correct answer is B: Performing a newborn's initial bath. Gloves should be worn during this procedure to protect against exposure to body fluids, such as amniotic fluid or blood. Assisting a mother with breastfeeding (Choice A) does not typically require gloves unless there are specific reasons for infection control. Administering vaccines (Choice C) and performing umbilical cord care (Choice D) are procedures that may require hand hygiene but not necessarily gloves, unless there is active bleeding or potential exposure to body fluids. The initial bath involves direct contact with body fluids, making it crucial to wear gloves for protection.

Correct Answer: D

Rationale: The correct answer is the sex chromosome received from the father. The father contributes either an X or Y chromosome, which determines the child's sex. This occurs at the moment of fertilization when the sperm carrying either an X (resulting in a female) or Y (resulting in a male) chromosome fertilizes the egg. Choices A, B, and C are incorrect because the presence of teratogens at the time of conception or ovulation does not determine the child's sex. While the sex chromosome received from the mother is important, it is the father's contribution that ultimately determines the child's sex.

Correct Answer: B

Rationale: The correct answer is B. According to the study by Fellman in 2013, the chances of having twins actually increase with parental age. Choice A is incorrect as the study does not specify a younger age for conceiving to increase the chances of twins. Choice C is incorrect as the frequency of intercourse before conception is not a highlighted factor in the study. Choice D is also incorrect as the study does not discuss the impact of fertility drugs on the likelihood of having twins.