Land plants evolved long before any animals appeared on earth. when they came onto land, they needed ways to keep from losing water, to reach the sun, and to produce oxygen. they started to convert the atmosphere from carbon dioxide to oxygen. which of these is believed to be the common ancestor of land plants?

Isotopes of the same element have differ in their

What is the significance of the protein-lined pits? a. protein attracts other proteins needed for atp synthesis within the cell. b. protein-lined pits are able to transport one molecule at a time down the concentration gradient within the cell. c. the polarity of proteins allows other polar molecules to attach and be transported in the cell by transport channels. d. receptors within the pits allow ligands to fuse and be transported into the cell by endocytosis.

What substance is the most acidic. lemon juice. tomato juice. sodium hydroxide. water