Ineed with #4
i have no idea what it is or what i need to do

Which of the following produces carbon dioxide? a. plants b. animals c. decomposers d. all of the above

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.

The embryos of a bird, a reptile, and a mammal are similar in appearance. how does comparing the physical appearance of embryos of different species support the theory of evolution? a. it shows that these organisms share a common ancestor. b. it provides evidence that these organisms eat the same foods. c. it shows that these organisms share the same habitat. d. it provides evidence that these organisms suffered a genetic mutation.