Many fish and aquatic plants can survive a cold winter because the layer of
ice that forms at the top of the lake insulates the water below and prevents
the lake from freezing solid. what unique property of water contributes to
this effect?

Water expands on cooling below 4 degrees Celcius.

Explanation:

This means the water becomes less dense because the same mass of water occupies more volume. This is called the ‘water anomaly’ because other liquids reduce in volume with temperatures.  Ice will, therefore, float on very cold water. In cold regions this ice sheet formation in lakes and oceans is significant in  insulating the waters below from losing more heat. Consequently, the waters below the ice sheet remain liquid maintaining the aquatic life below the ice.

spiders belong to a group of arachnids.

arachnids have the following traits :

they have two body parts.

they have eight legs unlike insects which have 6 legs.

they have no wings.

these traits distinguish them from insects.

the information that antonio is doubting us the statement that spiders differences are as a result of being first to evolve.

this is because the evolution of one species is independent of the other species.