Final answer:
The usual size of a fatty acid tail varies but is commonly long. Fatty acid tails give properties such as decreased rigidity and increased hydrophobicity. They achieve these properties through covalent bonds between carbon and hydrogen atoms. Option B is correct.
Step-by-step explanation:
The usual size of a fatty acid tail can vary, but the most common size is long. Fatty acid tails consist of a chain of carbon atoms with hydrogen atoms attached. These long tails give fatty acids properties such as decreased rigidity and increased hydrophobicity.
The length of the fatty acid tail affects its flexibility and the ability of the fatty acid to stack together. Longer tails result in decreased rigidity and increased flexibility, allowing the fatty acids to move more easily. This property is important for the structure and function of cell membranes.
Fatty acids achieve their properties through the covalent bonds between carbon and hydrogen atoms in the tail. The hydrophobic nature of the tail is a result of the nonpolar nature of the carbon-hydrogen bonds, which makes fatty acids insoluble in water.