The correct answer is an accumulation of microorganisms in deep marine environments.
Chalk rock refers to a pure form of limestone produced in tropical and warm seas about 100 million years ago in the Cretaceous period. The microscopic marine algae known as coccoliths thrived in the ancient seas. Their shells were comprised of calcite. With the death of the algae, their bodies sunk to the floor of the sea and sediment of chalk got deposited.
Over many years layers of chalk sediment got deposited and resulted in compaction of loose sediment into solid chalk rock.
Answer:
The correct answer is D. maintain membrane fluidity through its disruption of fatty acid packing.
Explanation:
<u>Cholesterol</u> is a steroid lipid and is a constituent of biological membranes. It regulates the <em>fluidity</em> of the membrane (so, option C is not correct). Since cell membranes are composed of another type of lipids, the phospholipids, which form a bilayer, cholesterol distributes between the phospholipid tails and avoids these molecules pack each other forming rigid clusters. Thus, the option which better explains the effect is <em>D. maintain membrane fluidity through its disruption of fatty acid packing.</em>
Somatic mutations can be passed on. B is the correct answer
The attached body form of Cnidarians would be polyp