Final answer:
The false statement concerning plant cold hardiness is that plants add antifreeze to their cells; they actually use other mechanisms such as supercooling and the accumulation of solutes. Deciduous plants drop their green chlorophyll, revealing brilliant fall colors, and the photoperiod triggers the first stage of cold hardiness. Evergreen conifers are an example of cold-tolerant plants that can photosynthesize early in spring.
Step-by-step explanation:
The statement that is NOT TRUE concerning plant cold hardiness is: Plants that are cold hardy add antifreeze into the cells of their tissues to lower their freezing point. While plants do have mechanisms to avoid freezing, such as the presence of solutes in the cytosol which may marginally lower the freezing point and prevent ice crystal formation, they do not add antifreeze in the same way that is used in vehicles. Instead, they employ strategies like supercooling and the accumulation of solutes to manage freezing temperatures.
The brilliant show of fall colors is due to the disappearance of green chlorophyll in the leaves before they fall off the deciduous trees. During fall, as the photoperiod shortens, deciduous plants begin to break down chlorophyll, leading to the appearance of other pigments such as carotenoids and anthocyanins, which contribute to the arrays of red, orange, and yellow leaves. The first stage of becoming cold hardy indeed involves the photoperiod, which signals the plants to prepare for the coming cold. Additionally, it is valid to compare the cold hardiness in plants with the freeze tolerance in animals, as both involve adaptations to survive in freezing temperatures. Finally, it is true that some trees can survive extreme temperatures well below freezing, but the exact limit varies among species.
Plants have developed various strategies to withstand cold temperatures. These include dormancy, a state in which a plant slows down its cellular activities, possibly sheds its leaves, and some may store food to prepare for new growth in the spring. Cold-tolerant plants, such as the evergreen conifers, retain their needle-shaped leaves year-round, allowing them to photosynthesize earlier in the spring than deciduous trees.