<span>X chromosomes is found in female cells and</span><span><span> males produce sperm with an X or a Y chromosome.</span> </span>
Most of the marine animals have a stream lined body, which means, they have a sharp and pointed at the front. The pointed front of the organism allow to cut the resistance of the water. In case, the body is not pointed at the front and it is blunt, the water current and flow would resist the movement of the organism further. So, for the locomotion purpose, it is important to have a streamlined body. Further smooth and hair less body also decrease the resistance during the movement in the water.
The right answer is: vitamin C and choline
Choline (vitamin B4) is the precursor on the one hand acetylcholine (important neurotransmitter and neuromodulator) and on the other hand, the cascade initiated by betaine (intermediate in the biological methylation and precursor of membrane lipids). In this, it is considered, by extension, as an integral part of the family of B vitamins,
Vitamin C protects against cellular aging, is essential for the immune defenses and increases the assimilation of iron of plant origin. It also contributes to the formation of collagen. Its deficiency leads to a disease called scurvy (hence the ascorbic acid name of vitamin C).