A strawberry farmer finds that, after a hard freeze, some of his strawberries are still alive. Which best explains why these strawberries were able to survive?

• A. They have larger leaves to protect the fruit than the other strawberries.
• B. They have different genetic variations that cause them to be more resistant to cold temperatures.
• C. They are able to reproduce more quickly than the other strawberries.
• D. The color of the strawberries is darker, and they maintain their temperature better than other strawberries.

Answer: (B)

Genetic variation among individuals means some plants have traits that help them withstand cold better. After a hard freeze, strawberries with genes for cold tolerance are more likely to keep their cells from freezing damage and to recover, so they survive while others die. Those survivors can grow and pass on those cold-tolerant traits to the next generation, so future plants are more likely to be hardy against cold. The other ideas don’t explain survival as well because larger leaves or darker color don’t directly protect the fruit from freezing, and reproducing quickly doesn’t address the immediate threat frost poses. The main idea is that differences in genetics lead to different responses to cold, and the ones with helpful traits are the ones that persist.