Nokea
What is the most basic unit of structure in living things?
- A. Cell
- B. Organelle
- C. Oxygen
- D. Pigment
Correct Answer: A
Rationale: The cell is indeed the most basic unit of life, forming the foundation of all living organisms. Cells are the building blocks of all living things, containing organelles that perform specific functions. While oxygen is essential for life, it is not a structural unit. Similarly, pigment is a component found within cells but is not the fundamental unit of structure. Therefore, the correct answer is 'A: Cell.'
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Which is the correct order of formed elements in blood from smallest to largest cell size?
- A. Erythrocytes, thrombocytes, and leukocytes
- B. Thrombocytes, leukocytes, and erythrocytes
- C. Thrombocytes, erythrocytes, and leukocytes
- D. Leukocytes, erythrocytes, and thrombocytes
Correct Answer: C
Rationale: The correct order of formed elements in blood from smallest to largest cell size is thrombocytes (platelets), erythrocytes (red blood cells), and leukocytes (white blood cells), making choice C the correct answer. Thrombocytes are the smallest, followed by erythrocytes, and then leukocytes. Choices A, B, and D are incorrect because they do not follow the correct order of cell size in blood formed elements.
Which term is used interchangeably with negative variation?
- A. Non-correlation
- B. Direct correlation
- C. Inverse correlation
- D. Positive correlation
Correct Answer: C
Rationale: The correct answer is C: Inverse correlation. Negative variation is synonymous with inverse correlation, indicating that as one variable increases, the other decreases. This relationship is the opposite of positive correlation, where both variables increase or decrease together. Non-correlation and direct correlation do not convey the concept of negative variation and are not interchangeable terms in this context. Non-correlation refers to variables that are not related or associated, while direct correlation indicates that as one variable increases, the other also increases. Positive correlation describes a relationship where both variables increase together, which is the opposite of negative variation.
If a biochemist isolates a large amount of pyruvate, which part of the cell is he working with?
- A. Chloroplasts
- B. Cytoplasm
- C. Mitochondria
- D. Nucleus
Correct Answer: B
Rationale: The correct answer is B: Cytoplasm. Pyruvate is a product of glycolysis, a metabolic pathway that takes place in the cytoplasm of the cell. Therefore, a biochemist isolating a large amount of pyruvate would be working with the cytoplasm of the cell. Choice A, Chloroplasts, is incorrect because pyruvate is not produced in chloroplasts, which are responsible for photosynthesis. Choice C, Mitochondria, is incorrect as pyruvate is produced in the cytoplasm before entering the mitochondria for further metabolism. Choice D, Nucleus, is incorrect as the nucleus is not involved in the production or isolation of pyruvate, which is a metabolic intermediate.
Which structure protects the lungs?
- A. Femur
- B. Ribcage
- C. Scapula
- D. Skull
Correct Answer: B
Rationale: The ribcage is the correct answer. It protects the lungs by providing structural support and shielding them from injury. The femur is a bone in the thigh and does not protect the lungs. The scapula is a shoulder blade bone, and the skull protects the brain, not the lungs.
What is a benefit of a taxonomic system?
- A. Researchers can describe how living things behave.
- B. Researchers can develop names for new organisms.
- C. Living things can be distinguished from nonliving things.
- D. Living things can be classified based on their molecular traits.
Correct Answer: D
Rationale: The correct answer is D. A taxonomic system allows scientists to classify living organisms based on their molecular and genetic traits. This classification helps in understanding the relationships and evolutionary history of different organisms, providing insights into their characteristics and behaviors. Choices A, B, and C do not directly relate to the primary purpose and benefit of a taxonomic system, which is the systematic classification of organisms.