Final answer:
The claim that 90% of the human body consists of water is false. The actual water content varies with age, from around 75% in infants to 50-60% in adults, and can be as low as 45% in the elderly.
Step-by-step explanation:
The statement that 90 percent of the human body is attributed to water weight is False. Human beings are indeed composed mostly of water; however, the accurate percentage of body water content differs through stages of life and among individual bodies. Specifically, newborn infants have about 75% of their body weight as water, adults have about 50-60%, and this figure can go as low as 45% in the elderly.
It's also important to note that the brain and kidneys have the highest water content at about 80-85%, while teeth have the least, at 8-10%. The percentage of water in the body also shifts inversely with fat content, meaning leaner individuals have a higher water percentage compared to those with more fat mass.