Rotational kinetic energy is the energy an object has due to spinning around an axis, depending on how fast it spins and how its mass is distributed. A wheel spinning in place shows energy stored purely in rotation about its axis, with no need for forward motion. The wheel’s angular velocity and its moment of inertia determine how much energy is in that rotation. In contrast, a car moving straight primarily has translational kinetic energy from linear motion; a ball rolling has both rotational and translational energy because it spins while moving forward; a person running mainly involves translational energy of the body’s movement. So the wheel spinning best illustrates rotational kinetic energy.

Polysaccharides are carbohydrate polymers formed by dehydration synthesis that attach many monosaccharides together. In this process, sugar units are linked by covalent bonds called glycosidic bonds, with a water molecule removed each time a new unit joins the chain. This long, repeating sugar backbone explains their functions: they can store energy, as starch in plants or glycogen in animals, or provide structural support, as cellulose in plants and chitin in some animals. They’re not single sugar units—that would be monosaccharides—nor enzymes that break down fats, and they aren’t lipids.

Genotype is the genetic makeup—the specific alleles an organism carries. Phenotype is what you can observe—the traits that result from how those genes are expressed, which is influenced by the environment. So the best statement captures that distinction: genotype = genetic information, phenotype = observable traits shaped by both genes and environment. For example, the same genetic potential for height can be realized differently depending on nutrition and health during development. The idea that both refer to environmental effects, or that genotype means observable traits, or that genotype is a set of proteins, doesn’t fit how genotype and phenotype are defined.

Kinetic energy is the energy of motion. When an object moves through space, its motion of the entire body, or the translation of its center of mass, constitutes translational kinetic energy. This form of energy increases with both mass and speed, shown by the formula 1/2 m v^2. The other terms describe stored or potential energy: elastic energy comes from deforming a material, gravitational energy (often called gravitational potential energy) depends on height in a gravitational field, and chemical energy is stored in bonds within molecules. So the energy tied directly to motion through space is translational kinetic energy.