What prevents a lake or ocean from freezing solid?

Which of these is not a function of some membrane proteins ? a. allowing polar molecules to enter the cell b. recognizing other types of cells c. receiving messeges from other cells b. carrying messages to oher cells

Which of the following statements is most likely correct about a rock belonging to the jurassic age and a rock belonging to the cambrian age? options: 1) they have identical fossils of organisms that have evolved over time. 2) both have animal fossils preserved in them due to weathering and erosion. 3) they contain different fossils because life on earth has changed through time. 4) the fossils in them were formed on the surface of earth due to exposure to sunlight.

Identify two examples of chemical reactions that you have encountered during the last week. identify an exothermic and endothermic reaction. explain.