Final answer:
Freezing-intolerant poikilotherms avoid freezing by increasing membrane unsaturated fatty acids, producing antifreeze proteins, and entering a state of torpor through hibernation or estivation to reduce metabolic rate.
Step-by-step explanation:
Freezing-intolerant poikilotherms, or animals whose internal temperature varies considerably, adopt various strategies to avoid freezing in cold environments. Here are three strategies these organisms exploit:
- Increasing the number of unsaturated fatty acids in their cell membranes, which enhances membrane fluidity at lower temperatures and prevents freezing.
- Production of antifreeze proteins that prevent ice crystal formation in tissues hence avoiding cellular damage during freezing temperatures.
- Entering a state of torpor during periods of extreme cold (hibernation) or extreme heat (estivation), dramatically lowering metabolic rate to conserve energy and reduce the chances of freezing.
These adaptive strategies help in ensuring survival through unfavorable temperature conditions by either avoiding the formation of ice crystals within their body tissues or by drastically reducing their metabolism to wait out the adverse conditions.