I think the answer is c hope is right
<span>The vertebrate nerve code is found dorsally while that of the crayfish is located ventrally of its body. Additionally, the ventral nerve cord of the crayfish is a solid ventral tube while that of the vertebrate is a hollow tube. All vertebrates are chordates, the dorsal nerve cord develops into nervous tissue of the brain and spinal cord; unlike the notochord which is the scaffolding for development of the bone and cartilage of the vertebral column. In the crayfish, they have a ventral nerve cord which is a collection of nerves found in the abdomen.</span>
A cell spends 10-20% of its time in Mitosis.
If this is wrong...sorry :)
Answer is membrane protein
Plasma membrane or cell membrane is made of lipoprotein (lipid and protein). The structure of the plasma membrane is based on the fluid mosaic model which gives basic description of the structure and behavior of membranes. The plasma membrane is a mosaic of phospholipids, cholesterol and proteins. Many proteins can move within the plasma membrane through membrane diffusion. The membrane proteins regulates the coming and going of substances into and out of the cell.
