What is the main purpose of biological classification?

Correct Answer: B

Rationale: Biological classification, also known as taxonomy, is the science of categorizing and organizing living organisms based on shared characteristics. The main purpose of biological classification is not to create a rigid and unchanging system (option A) or to simplify nature into neat and tidy categories (option C). Instead, it aims to help us understand the diversity of life on Earth and how different organisms are related to each other. By classifying organisms into groups based on their evolutionary relationships, we can gain insights into the interconnectedness of life and better appreciate the complexity and beauty of the natural world. Assigning organisms to specific ecological niches (option D) is more related to ecological studies rather than biological classification.

Correct Answer: C

Rationale: During a physical change in matter, the original substance undergoes a change in its physical state or appearance without any change in its chemical composition. This means that the original substance can be recovered by physical means, such as melting, freezing, boiling, or condensing. No new substance is formed (option A), the chemical composition remains the same (option B), and energy changes can occur but are not a defining characteristic of a physical change (option D). The ability to recover the original substance by physical means distinguishes physical changes from chemical changes.

Correct Answer: D

Rationale: Volume is the measure of the total amount of space occupied by an object. Mass refers to the amount of matter in an object, density is the mass per unit volume, and weight is the force of gravity acting on an object. When determining the space occupied by an object, volume is the appropriate measurement to consider. Therefore, the correct answer is D. Choices A, B, and C are incorrect as they do not directly indicate the total amount of space occupied by an object. Mass, density, and weight are relevant in different contexts and measurements compared to volume.

Correct Answer: C

Rationale: Density is the measure of the mass of a substance per unit volume and is commonly expressed in kilograms per cubic meter. Mass refers to the amount of matter in an object, weight is the force of gravity acting on an object, and volume is the amount of space an object occupies. In this context, density is the correct term for expressing the measure of mass per unit volume, making it the most appropriate choice among the options provided.

Correct Answer: A

Rationale: Mass is the amount of matter in an object and remains constant regardless of its location in the universe. Weight, on the other hand, is the force of gravity acting on an object and can vary depending on the gravitational pull at different locations. Density and volume can change based on the conditions the substance is in, so they are not constant properties. Therefore, the correct answer is mass as it does not change with changes in location.