Which is an example of a scientific theory?
A. If a person takes at least one vitamin per day, then it will reduce a person’s level of tiredness.
B. Organisms evolve over time due to changes in heritable physical characteristics.
C. On average, larger mammals sleep longer than smaller mammals.
D. If a plant receives pure water, then it will grow more than one that receives salt water.
Answer IS NOT "If a plant receives pure water, then it will grow more than one that receives salt water."
Organisms evolve over time due to changes in heritable physical characteristics.
The correct example of a scientific theory out of the given options is option B: Organisms evolve over time due to changes in heritable physical characteristics.
To determine which option represents a scientific theory, let's first understand what a scientific theory is. In science, a theory is an explanation or model that has been supported by a significant amount of evidence and is widely accepted by the scientific community. It is based on repeated observations, experimentation, and logical reasoning.
Examining the options:
A. "If a person takes at least one vitamin per day, then it will reduce a person’s level of tiredness" is a potential hypothesis that could be tested, but it does not represent a well-established and widely accepted scientific theory.
B. "Organisms evolve over time due to changes in heritable physical characteristics" represents the theory of evolution, which is a well-supported scientific theory with ample evidence from various scientific disciplines such as genetics, paleontology, and comparative anatomy.
C. "On average, larger mammals sleep longer than smaller mammals" seems more like an observation or generalization rather than a scientific theory. It may be supported by empirical data, but it does not explain why or how this phenomenon occurs.
D. "If a plant receives pure water, then it will grow more than one that receives salt water" appears to be a statement that could be tested through experimentation and potentially contribute to a scientific theory, but it is not an already established one.
Therefore, the correct answer is option B. "Organisms evolve over time due to changes in heritable physical characteristics."