Answer:
d) polyps; calcium carbonate
Explanation:
The Acanthaster planci It is a kind of invasive starfish, which destroys corals: it has poisonous spines and feeds on coral polyps at the expense of the reef.
On the other hand, CO2 reacts with water, forming carbonic acid and reducing the available calcium carbonate, an essential element so that marine organisms, from clams to hedgehogs, can form their skeletons and shells.
The answer is C, because covalent compounds can only form between those that are gases (at least at first)
Protons and neutrons are located inside the nucleus, while electrons are located outside. protons are positive, neutrons are neutral, and electrons are negative
Answer
Complex barrier to the flow of substances out of the cells,and restrictions to inflow of unwanted substances into the cells. The hydrophobic and hydrophilic nature of the cell membrane controls the entry of substances from the extracellular medium into the intracellualr. In addition the polarity restricts certain substance movement across the walls.
Serve as the selective channels for the influx of certain substances into the cells, and the out flux of wastes.This is through ion channels for the movements of ions across.
Provide insulation to the cells,to maintain the constant internal temperature,this is through the presence of lipids as( Phospholipids and cholesterol).The latter prevent the clogging of the lipids in the cell membrane therefore preventing frozen up of the cell membrane,providing insulation.
Separation of metabolic process in the cell.
Explanation:
Cell membrane-This is present in all cells.But the variation of its constituents makes it unique to each cell. Although it performs the same role, the location and role the cells it bounded, reflects its constituents, it is made up of lipids, carbohydrate, protein and cholesterol
