All living things are made up of four classes of biological macromolecules: carbohydrates, lipids, proteins, and nucleic acids. Macromolecules are large molecules composed of thousands of covalently connected atoms, also called polymers. A polymer is a long molecule consisting of many similar building blocks; the small building-block molecules are called monomers. All cells have thousands of different macromolecules, that vary among cells of an organism, vary more within a species, and vary even more between species. A huge variety of polymers can be built from a small set of monomers. What statements are true about the biological macromolecules. (Choose 3) Responses All biomolecules could be called carbon-based molecules. All biomolecules could be called carbon-based molecules. The monomers of DNA are nucleotides. The monomers of DNA are nucleotides. Ready cellular energy comes in the form of lipids. Ready cellular energy comes in the form of lipids. Carbohydrates contain nitrogen and therefore differ from the other macromolecules Carbohydrates contain nitrogen and therefore differ from the other macromolecules Cell membranes are made, in part, from phospholipids."

Answer 1

The following statements are true about biological macromolecules:

1. All biomolecules could be called carbon-based molecules. - This statement is true because all biological macromolecules, including carbohydrates, lipids, proteins, and nucleic acids, are primarily composed of carbon atoms.

2. The monomers of DNA are nucleotides. - This statement is true. DNA is made up of nucleotides, which are the monomeric units that compose the DNA polymer.

3. Cell membranes are made, in part, from phospholipids. - This statement is true as well. Phospholipids are a major component of cell membranes, forming a bilayer that provides structure and serves as a barrier.

The statement "Ready cellular energy comes in the form of lipids" is not correct, as carbohydrates (primarily in the form of glucose) are typically the main source of readily available energy for cellular processes. Additionally, "Carbohydrates contain nitrogen and therefore differ from the other macromolecules" is false because carbohydrates do not usually contain nitrogen; they are primarily made up of carbon, hydrogen, and oxygen.