Nokea
How many pairs of chromosomes are in a human cell?
- A. 46
- B. 23
- C. 64
- D. 32
Correct Answer: B
Rationale: The correct answer is B: 23. Humans have 23 pairs of chromosomes, totaling 46 chromosomes. Each pair consists of one chromosome inherited from the mother and one from the father, making a total of 46 chromosomes in a human cell. Choice A (46) is incorrect as it represents the total number of chromosomes, not pairs. Choice C (64) and D (32) are incorrect as they do not reflect the accurate number of chromosome pairs in a human cell.
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What does the phrase 'survival of the fittest' refer to?
- A. Organisms with the most complex anatomical structures are more likely to survive and reproduce.
- B. Organisms that demonstrate the best adaptations to their environment have a higher chance of survival and reproduction.
- C. All organisms have an equal probability of survival and reproductive success regardless of their traits.
- D. Only the strongest and most aggressive individuals within a population will survive and reproduce.
Correct Answer: B
Rationale: The phrase 'survival of the fittest' is often associated with the concept of natural selection, proposed by Charles Darwin. Natural selection is the process by which organisms best adapted to their environment are more likely to survive and reproduce, passing on their advantageous traits to the next generation. This process does not necessarily favor the most complex anatomical structures (option A) or the strongest and most aggressive individuals (option D). Instead, it emphasizes the importance of adaptations that enhance an organism's ability to survive and reproduce in a specific environment. Option C is incorrect because natural selection results in differential reproductive success based on an organism's traits, meaning that not all organisms have an equal probability of survival and reproductive success.
What is the breakdown product of creatine phosphate, an energy source used for short bursts of muscle activity?
- A. Glucose
- B. Lactic acid
- C. Carbon dioxide
- D. Creatine
Correct Answer: B
Rationale: Creatine phosphate is utilized as an immediate energy source for short bursts of muscle activity. When it breaks down, it yields lactic acid as a byproduct. Lactic acid accumulation during intense exercise can lead to muscle fatigue and soreness. Therefore, the correct answer is lactic acid. The other choices are incorrect: Glucose is a different energy source derived from carbohydrates; Carbon dioxide is a waste product of cellular respiration, not specifically from creatine phosphate breakdown; Creatine is the precursor compound to creatine phosphate and is not the breakdown product.
Which of the following organs is responsible for detoxifying chemicals and metabolizing drugs?
- A. Kidneys
- B. Liver
- C. Heart
- D. Pancreas
Correct Answer: B
Rationale: The correct answer is B: Liver. The liver plays a crucial role in detoxifying chemicals and metabolizing drugs. It also produces bile for digestion. The liver contains enzymes that help metabolize drugs and toxins, making them easier for the body to eliminate. The kidneys are primarily responsible for filtering blood and regulating fluid balance, the heart's main function is to pump blood, and the pancreas produces digestive enzymes and hormones like insulin, but they do not have the primary function of detoxifying chemicals and metabolizing drugs.
What is the correct arrangement of the small intestine segments, from the stomach to the large intestine?
- A. Duodenum, Jejunum, Ileum
- B. Jejunum, Ileum, Duodenum
- C. Ileum, Duodenum, Jejunum
- D. None of the above
Correct Answer: A
Rationale: The correct arrangement of the small intestine segments, from the stomach to the large intestine, is Duodenum, Jejunum, and Ileum. The small intestine begins with the duodenum, then continues to the jejunum, and finally, it ends with the ileum before connecting to the large intestine. Option A, 'Duodenum, Jejunum, Ileum,' is the correct sequence. Choices B and C have the segments in incorrect order, not following the anatomical arrangement of the small intestine. Therefore, they are incorrect. Option D, 'None of the above,' is also incorrect as the correct sequence is provided in option A.
What is the primary function of the lymphatic system?
- A. To transport oxygen throughout the body
- B. To filter blood and remove waste
- C. To fight infection and remove excess fluid
- D. To transport hormones
Correct Answer: C
Rationale: The correct answer is C: 'To fight infection and remove excess fluid.' The lymphatic system plays a crucial role in the body's immune response by fighting infections through lymphocytes and removing excess fluid from tissues, maintaining fluid balance. It does not primarily transport oxygen, filter blood, or transport hormones. While the lymphatic system is involved in lipid absorption and transport, its primary functions are related to immunity and fluid balance.