As surface water in a lake cools from 4 °C to 0 °C, the water expands and becomes less dense. Why is this change in the water beneficial to the organisms living in the lake? As the water cools to freezing, spaces form between water molecules, providing microhabitats for small organisms. Frozen surface water insulates the water below it, maintaining a habitat where organisms can overwinter. Cooler water is less viscous than warmer water, making it easier for organisms to move through the water. Less dense water holds more dissolved compounds, keeping water from freezing so organisms survive winter.

Match the types of competition to their descriptions

Aresearcher designed an investigation to test what effect eating different types of food would have on blood insulin levels. she selected 10 male subjects who were all 25 years of age and in good health. the experiment took place over 3 days. at 8: 00 a.m. on each day, the subjects ate a meal consisting of only 1 type of food. they had their blood insulin levels measured after consuming the meal. on day 1 they ate a high fat diet, on day 2 they ate a high protein diet, and on day 3 they ate a high sugar diel what is the independent variable in this experiment? a the age of the subjects b the blood insulin level c the type of food consumed d the time of day the meal was consumed

The function of the ciliary escalator is to