While genetic mutations provide the raw material for long-term evolutionary change, organisms also exhibit phenotypic plasticity to survive immediate environmental fluctuations. For instance, certain species of water fleas develop defensive helmets only when they detect chemical cues from predators. This rapid, non-heritable alteration in physical form allows a single genotype to produce diverse traits, illustrating how organisms dynamically adjust to ecological challenges without immediate alterations to their underlying DNA sequence.
As it is used in the passage, the word plasticity most nearly refers to the:
- Aphysical malleability and flexibility of synthetic or organic materials
- Bpermanent alteration of an organism's genetic code to ensure survival
- ability of an organism to alter its physical traits in response to its environmentAnswer
- Dgradual development of a single, permanent defense mechanism over generations
Answer
the ability of an organism to alter its physical traits in response to its environment
The correct answer refers to an organism's ability to change its physical features based on its surroundings. The passage supports this by describing phenotypic plasticity as a 'rapid, non-heritable alteration in physical form' that occurs in response to 'environmental fluctuations' (such as cues from predators) without modifying the organism's DNA sequence.
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Key Concept
Decoding low-frequency academic vocabulary in context by analyzing direct definitions and examples.
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