Explain vascular bundles in leaf ?

Animal bodies (and even plant bodies for that matter) are complex enough that life couldn't exist without enzymes. enzymes are usually large, complex biological catalysts that are expensive to make. enzymes speed up the rate of chemical reactions without being used up during the reaction (they can be reused many times). they are highly specific in the reactions they regulate. knowing what enzymes are and how they function, why does this explain why complex life forms could not exist if there were no enzymes.

Seen in some gram-positive bacilli, occurs when only the inner portion of a cell wall is deposited across the dividing cell. this new cross wall puts tension on the outer layer of the old cell wall. eventually, the outer wall breaks at its weakest point with a snapping movement that tears it most of the way around. the daughter cells can then remain hanging together almost side by side being held by a small remnant of the original outer wall. choose from the following statements the ones that correctly discuss reproduction using binary fission in a bacterial cell. select all that apply. view available hint(s) select all that apply. due to the stretching of the cytoplasmic membrane, both cells will contain a complete genome. each daughter cell will contain an equal number of organelles. the daughter cell will be a permanently smaller copy of the mother cell but will contain a complete genome. each daughter cell is an exact copy of the other, both genetically and morphologically

Keeping in mind the life cycle of bacteriophages, consider the following problem: during the reproductive cycle of a temperate bacteriophage, the viral dna inserts into the bacterial chromosome where the resultant prophage behaves much like a trojan horse. it can remain quiescent, or it can become lytic and initiate a burst of progeny viruses. several operons maintain the prophage state by interacting with a repressor that keeps the lytic cycle in check. insults (ultraviolet light, for example) to the bacterial cell lead to a partial breakdown of the repressor, which in turn causes the production of enzymes involved in the lytic cycle. as stated in this simple form, would you consider this system of regulation to be operating under positive or negative control?