Is the movement of substances from lower to higher concentration across a semipermeable membrane that must have a specific protein carrier and cell expenditure of energy. select one: a. facilitated diffusion b. diffusion c. active transport d. osmosis e. endocytosis

20 points and brainlist 1. london has suffered from terrible air pollution for at least seven centuries. why is the city so prone to its famous “london fog? ” what did london do to get rid of its air pollution? 2. why does air pollution cause problems in developing nations more than in developed ones?

The cretaceous period spanned the time interval between and 65 million years ago. 250 million 144 million 75 million 200 million

This is an active transport mechanism by which cells pump sodium and potassium ions against the concentration gradient