Answer:
Explanation:
Hard-shelled organisms absorbed calcium and carbonate iron and use them in making their hard shells which are calcium carbonate. When these organisms die, there shells are used in the formation of limestone rock. Limestone rocks are a huge store carbon. When acid rain reacts with limestone, these trapped carbon are released to the atmosphere thereby causing an Increase in atmospheric carbon.
Conclusively, the accumulation of limestone rock and subsequent reactions with acids such as acid rain has resulted in an increased atmospheric carbon throughout the years.
Answer:
B. A film of food wrap
Explanation:
The membrane is supposed to keep the contents safe inside .Not many things can enter inside and almost nothing can come outside, this being the selectively permeable nature of the membrane.
The plasma membrane, or the cell membrane, provides protection for a cell. It also provides a fixed environment inside the cell. And that membrane has several different functions. One is to transport nutrients into the cell and also to transport toxic substances out of the cell. Another is that the membrane of the cell, which would be the plasma membrane, will have proteins on it which interact with other cells. Those proteins can be glycoprotein, meaning there's a sugar and a protein moiety, or they could be lipid proteins, meaning there's a fat and a protein. And those proteins which stick outside of the plasma membrane will allow for one cell to interact with another cell. The cell membrane also provides some structural support for a cell. And there are different types of plasma membranes in different types of cells, and the plasma membrane has in it in general a lot of cholesterol as its lipid component. That's different from certain other membranes within the cell. Now, there are different plants and different microbes, such as bacteria and algae, which have different protective mechanisms. In fact, they have a cell wall outside of them, and that cell wall is much tougher and is structurally more sound than a plasma membrane is.
Answer:c. Separated DNA is attached to the cell membrane before the cell divides.
Explanation:
The prokaryotes are single celled organisms. These are simple organisms which reproduce through asexual mode of reproduction that is cell division. They do not posses well define nucleus. Thus the genetic material remain in the cytoplasm of the cell. On cell division the genetic material (DNA) is distributed into halves for development of two daughter cells. Due to lack of nucleus and it's associated membrane the separated DNA get attach to the membrane before the cell actually divides.
<span>A parent DNA molecule replicates, resulting in two daughter DNA molecules. </span>Each daughter molecule contains one DNA strand from the parent molecule.
