Answer:
Because DNA molecules are extremely long.
Explanation:
DNA molecule is made up of only four types of nucleotides that are adenine, guanine, cytosine, and thymine. These four types of nucleotide encode all the information necessary for the formation and working of the entire organism because each DNA strand is as long as 2 meter which contains millions of base pairs.
The four nucleotides are arranged in the DNA strand with many different combinations which results in the formation of codons sequence that contains all the information about the cell. This long DNA is compressed several times to fit in the nucleus.
I believe it's A!!! ( Hoped I helped️)
Answer;
-Pellicle
Explanation;
-Protist cells may contain a single nucleus or many nuclei; they range in size from microscopic to thousands of meters in area. Protists may have animal-like cell membranes, plant-like cell walls, or may be covered by a pellicle.
-On a paramecium's exterior is found the pellicle. The pellicle is stiff to maintain the paramecium's shape and provide stability but it is also flexible to allow movement. It also acts as an attachment site for external organelles such as cilia.
The aorta carries oxygenated blood from the right ventricle to the rest of the body for energy and metabolism.
