A car brakes to a stop on a level road. Which of the following forces does NOT do work on the car?

Correct Answer: B

Rationale: The normal force from the road does not do work on the car because it is perpendicular to the direction of motion. Work is defined as force applied in the direction of motion, so the normal force, which acts perpendicular to the motion of the car, does not contribute to the work done on the car. The braking force applied by the wheels, the gravitational force on the car, and the friction force between the tires and the road all act in the direction of motion and contribute to the work done on the car. In this scenario, the normal force is supporting the weight of the car and keeping it from sinking into the road, but it does not transfer energy to the car as it moves.

Correct Answer: B

Rationale: Pharyngeal pouches in vertebrates are an example of homologous structures because they share a common evolutionary origin. Despite developing into different structures in various vertebrate groups, such as the jaw and inner ear in humans, these structures originated from the same ancestral feature. This concept of homology highlights the evolutionary relationship between different species and how structures can be modified over time to serve different functions while retaining a common origin. Choice A is incorrect because analogous structures have similar functions but different evolutionary origins, which does not apply to pharyngeal pouches. Choice C is incorrect as vestigial structures are remnants of features that were functional in ancestors but have reduced or lost their original function, which is not the case for pharyngeal pouches. Choice D is incorrect because atavisms refer to the reappearance of traits absent in recent generations, which is not the characteristic of pharyngeal pouches.

Correct Answer: B

Rationale: The external body covering, which is the skin, is composed of epithelial tissue. Epithelial tissue serves as a protective barrier against pathogens, chemicals, and physical damage. It also helps regulate body temperature through processes like sweating. Choice A (Muscle tissue) is incorrect as muscles are responsible for movement and not the external body covering. Choice C (Bone marrow) is incorrect as it is a component of the skeletal system and not the external body covering. Choice D (Cartilage) is incorrect as cartilage is a type of connective tissue found in joints and the structure of some body parts, not the external body covering.

Correct Answer: B

Rationale: The epidermis is the correct answer as it is the outermost layer of the skin, providing protection against pathogens and the environment. It consists of multiple layers, including the stratum corneum, which is the outermost layer of the epidermis. The dermis is located beneath the epidermis, offering structural support and housing blood vessels, nerves, and glands. The hypodermis is the deepest layer of the skin, made up of fat and connective tissue that secures the skin to underlying structures. Choice A, Dermis, is incorrect as it is located beneath the epidermis. Choice C, Hypodermis, is incorrect as it is the deepest layer of the skin, not the outermost. Choice D, Stratum corneum (part of the epidermis), is not the correct answer as it is a specific layer within the epidermis and not the overall outermost layer of the skin.

Correct Answer: B

Rationale: During cellular respiration, glucose undergoes a series of reactions in the presence of oxygen to produce energy in the form of ATP. The main waste product released in this process is carbon dioxide, which is eliminated from the body through exhalation. While water is also produced as a byproduct of cellular respiration, carbon dioxide is considered the primary waste product. Oxygen is not a waste product but is actually consumed during cellular respiration to aid in breaking down glucose. Protein is essential for various cellular functions but is not a waste product of cellular respiration; instead, proteins are broken down into amino acids for cellular processes.