Nokea
Which nitrogenous bases pair with each other in DNA?
- A. A-G and T-C
- B. A-T and C-G
- C. A-T and T-T
- D. C-C and G-G
Correct Answer: B
Rationale: In DNA, nitrogenous bases pair with each other in a specific manner known as complementary base pairing. Adenine (A) always pairs with Thymine (T), and Cytosine (C) always pairs with Guanine (G). This pairing is essential for maintaining the structure and function of DNA. Option B is the correct answer as it correctly identifies the nitrogenous bases that pair with each other in DNA. Choices A, C, and D are incorrect because they do not follow the established base pairing rules in DNA. A-T and C-G are the complementary base pairs in DNA, ensuring the stability and replication fidelity of the genetic material.
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Which type of nutrient requires the most complex and lengthy digestion process?
- A. Carbohydrates
- B. Proteins
- C. Fats
- D. Vitamins
Correct Answer: B
Rationale: Proteins require the most complex and lengthy digestion process compared to the other nutrient types provided. When proteins are consumed, they undergo a process where they need to be broken down into amino acids, which are essential building blocks of proteins. This intricate digestion process begins in the stomach aided by stomach acid and enzymes, proceeds to the small intestine where further enzymes break down proteins into amino acids, and concludes with the absorption of these amino acids into the bloodstream for various bodily functions. Carbohydrates and fats also require digestion, but the process for breaking down proteins into amino acids is notably more intricate and time-consuming. In contrast, vitamins do not require digestion in the same manner as proteins, carbohydrates, and fats because they are already in a form that can be readily absorbed by the body.
Acids are generally characterized by a sour taste and the ability to:
- A. Turn litmus paper red
- B. Conduct electricity in solution
- C. Neutralize bases
- D. React explosively with metals
Correct Answer: C
Rationale: Acids are known for their sour taste and their ability to neutralize bases, which is a defining characteristic of their acidic nature. When acids neutralize bases, salts and water are formed, highlighting the unique property of acids. The other options are incorrect: Option A, 'Turn litmus paper red,' is a test for acidity but not a defining characteristic of acids; Option B, 'Conduct electricity in solution,' pertains to the electrolytic properties of acids rather than their defining trait; Option D, 'React explosively with metals,' is not a general characteristic of acids. Therefore, the correct feature associated with acids is their capability to neutralize bases, making option C, 'Neutralize bases,' the correct answer.
Which enzyme breaks down carbohydrates like starches and sugars in the mouth?
- A. Pepsin
- B. Lipase
- C. Amylase
- D. Trypsin
Correct Answer: C
Rationale: The correct answer is Amylase. Amylase is the enzyme responsible for breaking down carbohydrates like starches and sugars in the mouth. Pepsin is a digestive enzyme that breaks down proteins in the stomach, lipase breaks down fats, and trypsin is another enzyme that breaks down proteins in the small intestine. Therefore, choices A, B, and D are incorrect for this question.
Which of the following can weaken the immune system and increase susceptibility to infections?
- A. Regular exercise
- B. Balanced diet
- C. Chronic stress
- D. Adequate sleep
Correct Answer: C
Rationale: Chronic stress can weaken the immune system by increasing the production of stress hormones like cortisol, which can suppress the immune response. This suppression can make individuals more susceptible to infections and illnesses. Conversely, regular exercise, a balanced diet, and adequate sleep actually support a healthy immune system and help strengthen it. Choices A, B, and D are incorrect as they are factors that generally contribute positively to the immune system. Regular exercise, a balanced diet, and adequate sleep are crucial for maintaining overall health and boosting the immune system rather than weakening it.
Which of the following is NOT a major component of a healthy blood pressure reading?
- A. Systolic pressure (peak pressure during ventricular contraction)
- B. Diastolic pressure (pressure within arteries during ventricular relaxation)
- C. Pulse pressure (difference between systolic and diastolic pressure)
- D. Blood oxygen saturation levels. While blood oxygen levels are crucial for overall health, they are not directly reflected in a blood pressure reading.
Correct Answer: D
Rationale: Blood oxygen saturation levels are essential for overall health but are not directly part of a blood pressure reading. A healthy blood pressure reading consists of systolic pressure, diastolic pressure, and pulse pressure. Systolic pressure represents the peak pressure during ventricular contraction, diastolic pressure reflects the pressure within arteries during ventricular relaxation, and pulse pressure is the difference between systolic and diastolic pressure. These components collectively provide information about the pressure variations within the arteries throughout the cardiac cycle phases, contributing to the assessment of cardiovascular health. Therefore, choice D, blood oxygen saturation levels, is not a major component of a healthy blood pressure reading and is the correct answer. Choices A, B, and C are major components of a healthy blood pressure reading and directly relate to the pressure variations within the arteries during different phases of the cardiac cycle.