Amembrane that only "lets" certain molecules in while keeping other molecules out is

Select the correct answer. which formula describes newton’s second law of motion? a. force=mass x accerlaration b. mass/accerlaration c. mass x volacity d. mass/ volacity

Several bird species feed in a certain species of tree. each bird species feeds in a different part of the tree. which statement is true of these bird species? a. they have adapted to different niches due to competition b. they have a carnivorous relationship with the tree species. c. they have adapted to different niches due to predation d. they have a symbiotic relationship with the tree species.

Which of these has happened to your food by the time it reaches your small intestine? a. all the macromolecules have been broken down completely. b. lipids and starches have been partially broken down. c. starches and proteins have been partially broken down. d. proteins and lipids have been broken down into subunits.