What surrounds all cells and control what enter and leaves the cell

1. the is the thinnest part of the earth. 2. the is the thickest part of the earth. 3. what metals are mentioned in the text?

Select all that apply genes are specific nucleotide sequences occur in numbers that are the same as the number of chromosomes are located in a specific place on a chromosome determine the traits of an organism are units of rna

According to theories of how life began, how did early organic molecules begin to separate from the outside world? a: specialized enzymes were required b: chains of amino acids created a barrier c: formation of microspheres or vesicles d: rna catalyzed the formation of membranes