Which of the following statements is NOT true about DNA?
- A. DNA contains the nucleotides A, T, C, G and is read 5' to 3'.
- B. DNA contains genetic information and is tightly coiled with proteins to form chromosomes.
- C. DNA contains the nucleotides A, T, C, G and is read 3' to 5'.
- D. DNA is a double-stranded molecule connected by hydrogen bonds.
Correct Answer: C
Rationale: The correct answer is C because DNA is typically read from the 5' end to the 3' end, not from 3' to 5'. Choices A, B, and D are all true statements about DNA. DNA contains the nucleotides A, T, C, G and is read in a 5' to 3' direction. DNA also contains genetic information and is tightly coiled with proteins to form chromosomes. Additionally, DNA is a double-stranded molecule connected by hydrogen bonds.
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Which cavity is primarily lined by the peritoneum?
- A. Abdominal
- B. Dorsal
- C. Ventral
- D. Thoracic
Correct Answer: A
Rationale: The correct answer is 'Abdominal.' The peritoneum primarily lines the abdominal cavity, providing support and protection to abdominal organs. It is a serous membrane that covers the abdominal organs and the abdominal wall, aiding in their function and protection. Choice B, 'Dorsal,' is incorrect because the peritoneum does not primarily line the dorsal cavity. Choice C, 'Ventral,' is incorrect as the peritoneum is not primarily associated with the ventral cavity. Choice D, 'Thoracic,' is incorrect because the peritoneum primarily lines the abdominal cavity and is not primarily found in the thoracic cavity.
What is the end product of glycolysis?
- A. Lactic acid
- B. ATP
- C. NADPH
- D. Pyruvic acid
Correct Answer: D
Rationale: The correct answer is D: Pyruvic acid. The end product of glycolysis is pyruvic acid, not lactic acid, ATP, or NADPH. Pyruvic acid is a key intermediary in cellular respiration and can be further metabolized to produce energy through processes like the citric acid cycle and oxidative phosphorylation. Lactic acid is produced in the absence of oxygen during fermentation, ATP is a product of cellular respiration but not the direct end product of glycolysis, and NADPH is generated in other metabolic pathways such as the pentose phosphate pathway, not in glycolysis.
Which type of blood vessel carries blood back to the heart?
- A. Artery
- B. Vein
- C. Capillary
- D. Lymphatic vessel
Correct Answer: B
Rationale: The correct answer is B: Vein. Veins carry blood back to the heart from various parts of the body, functioning as the vessels that return blood to the heart. Arteries, on the other hand, carry blood away from the heart to different parts of the body to deliver oxygen and nutrients. Capillaries are tiny blood vessels where the exchange of gases, nutrients, and waste products occurs between the blood and tissues. Lymphatic vessels are part of the lymphatic system, responsible for maintaining fluid balance and aiding in immunity. Therefore, the correct choice is B as it directly relates to the blood flow back to the heart.
What type of joint connects the bones of the skull?
- A. Hinge joint
- B. Fibrous joint
- C. Ball-and-socket joint
- D. Pivot joint
Correct Answer: B
Rationale: The correct answer is B: Fibrous joint. Fibrous joints connect the bones of the skull, providing stability with little to no movement. These joints are made of fibrous connective tissue, which holds the bones tightly together and prevents movement, making them ideal for the structure of the skull.
Choice A: Hinge joint is incorrect because hinge joints allow movement in a single plane like the elbow or knee, which is not characteristic of the joints in the skull.
Choice C: Ball-and-socket joint is incorrect as this type of joint allows for a wide range of movement in multiple planes, such as the hip and shoulder joints, which is not the case for skull bones.
Choice D: Pivot joint is incorrect as pivot joints allow rotation around a central axis, as seen in the joint between the first and second cervical vertebrae (atlas and axis), but not in the skull bones.
What is the function of the esophagus in the digestive system?
- A. To absorb nutrients
- B. To transport food from the mouth to the stomach
- C. To break down food
- D. To absorb water
Correct Answer: B
Rationale: The esophagus functions to transport food from the mouth to the stomach through a process called peristalsis, which involves a series of muscle contractions that push the food downward along the digestive tract. Absorbing nutrients (Choice A) is typically done in the small intestine, breaking down food (Choice C) is primarily the role of the stomach and small intestine, and absorbing water (Choice D) mainly occurs in the large intestine.