PLEASE HELP OUT !! Which options describe patterns found in the fossil record?
(Select all that apply.)

Earth’s species have remained constant throughout time.
Links exist connecting the lineage of different species.
Most of the species that have ever existed on Earth are still alive today.
Mass extinction events occur periodically throughout time.

Which of the following statements regarding anfinsen's denaturing experiments with ribonuclease a (rnase a) are valid? exposing the denatured protein to air oxidation and then dialysis to remove urea restored the protein to its original functionality. removing urea by dialysis and then allowing air oxidation of the denatured protein restored the protein to its original functionality. denaturing the protein with both urea and β-mercaptoethanol yielded an inactive protein. anfinsen concluded that protein folding is determined by its primary sequence.

Which of the following describes a difference when gram-positive bacteria are compared to gram-negative bacteria?

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.