Nursing Elites

1. A substance is only considered acidic if it has a pH less than what?

• A. 12
• B. 9
• C. 7
• D. 4

Correct answer: C

Rationale: A substance is considered acidic if its pH is less than 7. pH values below 7 indicate acidity, while pH values above 7 indicate alkalinity or basicity. Substances with a pH less than 7 are categorized as acidic, not above it. Therefore, a substance is classified as acidic if its pH is less than 7, making choice C the correct answer. Choices A, B, and D are incorrect because a pH of 12, 9, and 4, respectively, are all above 7, and therefore not indicative of acidity.

2. Describe the mechanism by which genes are transmitted from parents to offspring.

• A. Blending of parental genes, resulting in an average of their traits.
• B. Random assortment of alleles during meiosis, leading to unique combinations in each offspring.
• C. Inheritance of solely dominant alleles, masking the influence of recessive ones.
• D. Direct transfer of both parental genomes, creating identical copies of the parents.

Correct answer: B

Rationale: A) Blending of parental genes, resulting in an average of their traits, is not an accurate description of how genes are transmitted. In reality, genes are not blended but rather passed down in discrete units. B) Random assortment of alleles during meiosis is the correct mechanism by which genes are transmitted from parents to offspring. During meiosis, homologous chromosomes separate, and alleles are randomly distributed to the gametes, leading to unique combinations of genes in each offspring. C) Inheritance of solely dominant alleles, masking the influence of recessive ones, is not an accurate representation of gene transmission. Offspring inherit alleles from both parents, and the expression of dominant or recessive traits depends on the specific combination of alleles. D) Direct transfer of both parental genomes, creating identical copies of the parents, is not how genes are transmitted. Offspring inherit a unique combination

3. Which of the following is not a component of blood?

• A. Red blood cells
• B. White blood cells
• C. Platelets
• D. Cartilage

Correct answer: D

Rationale: The correct answer is D: Cartilage. Cartilage is not a component of blood. Blood primarily consists of red blood cells, white blood cells, and platelets. Red blood cells are responsible for carrying oxygen, white blood cells are part of the immune system, and platelets are essential for blood clotting. Cartilage, on the other hand, is a type of connective tissue found in various parts of the body, such as the joints and nose, but it is not present in the blood. Therefore, choices A, B, and C are incorrect as they are components of blood, while choice D, Cartilage, is the correct answer as it is not a component of blood.

4. Which valve prevents the return of blood into the right ventricle?

• A. Pulmonary semilunar valve
• B. Aortic semilunar valve
• C. Tricuspid valve
• D. Mitral valve

Correct answer: A

Rationale: The correct answer is A: Pulmonary semilunar valve. The pulmonary semilunar valve is located between the right ventricle and the pulmonary artery. It opens to allow blood to be pumped into the pulmonary artery but closes to prevent blood from returning back into the right ventricle. The aortic semilunar valve is located between the left ventricle and the aorta. The tricuspid valve is located between the right atrium and right ventricle, and the mitral valve is located between the left atrium and left ventricle. Therefore, the pulmonary semilunar valve is the specific valve responsible for preventing the backflow of blood into the right ventricle during the cardiac cycle.

5. During which phase of meiosis do chiasmata structures form?

• A. Prophase I
• B. Prophase II
• C. Metaphase I
• D. Metaphase II

Correct answer: A

Rationale: Chiasmata structures, where crossing over occurs, form during Prophase I of meiosis. This phase is characterized by homologous chromosomes pairing up and crossing over, leading to the exchange of genetic material between non-sister chromatids. Chiasmata are visible points of contact where genetic material has been exchanged, and they play a critical role in genetic diversity. Prophase II is the phase where chromosomes condense again in the second meiotic division, but chiasmata formation occurs in Prophase I. Metaphase I is the phase where homologous chromosomes align at the metaphase plate, not where chiasmata form. Metaphase II is the phase where replicated chromosomes align at the metaphase plate in the second meiotic division, but chiasmata formation occurs earlier in Prophase I.

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