The flow of energy from one level to another does not happen with 100% efficiency. The producers only transfer 10% of the energy they absorb from the Sun. The major chunk of the absorbed energy goes into the growth of the producers, the rest gets lost in the form of waste (shedding of leaves, reproduction, etc.) and the remaining 10% is the amount that is available to the primary consumers. So by this logic, if there is 150,000 KJ of energy available at the producer level, then, only 15,000 KJ of energy will get transferred to the primary consumers.
Cell membrane - the thin layer of protein and fat that surrounds the cell, but is inside the cell wall. The cell membrane is semipermeable, allowing some substances to pass into the cell and blocking others.
The answer is written on the pic I sent you with this
Integumentary system I believe
the main difference is that bacteria are free-living cells that can live inside or outside a body, while viruses are a non-living collection of molecules that need a host to survive.
Many bacteria help us: living in our gut digesting and helping absorption of our food, fixing nitrogen and decomposing organic materials in soil. Similarly, not all viruses are bad—we now know there are also beneficial viruses present in our gut, skin and blood that can kill undesirable bacteria and more dangerous viruses.
