AP BIOLOGY

Detailed explanation-1: -Water is the most abundant fraction of a cell.

Detailed explanation-2: -Water is the most abundant molecule in cells, accounting for 70% or more of total cell mass.

Detailed explanation-3: -Cell consists of 70-90% water, 10-15% proteins, 3% carbohydrates, 2% lipids and 5-7% nucleic acids.

Detailed explanation-4: -Cellulose is the most abundant organic compound on Earth. It is the main constituent of plant fiber; plants contain on average 33% cellulose, and cotton is the purest form at 90%.

Detailed explanation-5: -Oxygen is the most abundant element in the human body, accounting for about 65% of a person’s mass.