Answer: Option B
Explanation: The thin layer that forms the outer covering of the cell is known as the cell membrane. It is composed of the lipid bilayer which as embedded proteins.
This membrane is selectively permeable which means it allows only specific molecules to pass through them.
The main function of cell membrane is to protect the cell from the outer environment and by the invasion of harmful bacteria and viruses.
Answer: Paleozoic
Explanation: The Paleozoic Era, which ran from about 542 million years ago to 251 million years ago, was a time of great change on Earth. The era began with the breakup of one supercontinent and the formation of another plants became widespread. And the first vertebrate animals colonized land.
Answer:
7
Explanation:
There are 12 total pairs of ribs. 1-7 are attached directly to the sternum by costal cartilages, making them true pairs. 8-10 are fake pairs, which means they're attached indirectly to the sternum. And 11 and 12 and free floating ribs, meaning they aren't attached.
The answer for this question is B
It is not it something like sand because it would keep the fossil preserved.
