What do positive feedback mechanisms do?

Correct Answer: B

Rationale: Positive feedback mechanisms amplify or increase changes in a system, moving conditions away from the normal state. This makes choice B the correct answer. Choice A is incorrect as positive feedback does not cause long-term changes but rather accelerates deviations from the norm. Choice C is incorrect because positive feedback does not bring conditions back to normal; instead, it amplifies deviations. Choice D is incorrect as positive feedback does not usually lead to stable conditions but rather to further deviations from the normal state.

Correct Answer: B

Rationale: In the anatomical position, the palms are facing forward, not backward. Choice A is correct because the head is indeed facing to the front. Choice C is correct as the body is erect. Choice D is correct as the upper limbs are positioned at the sides. Therefore, the incorrect statement is that the palms are facing forward.

Correct Answer: D

Rationale: The correct answer is D: Organelles, cells, tissues, organs, organ systems. This list correctly depicts the increasing levels of complexity in biological organization. It starts with organelles, which are subunits within cells, followed by cells, then tissues (groups of cells working together), organs (comprised of different tissues), and finally organ systems (multiple organs working together). Choices A, B, and C are incorrect as they do not follow the logical progression of complexity from smaller units to larger, more complex structures.

Correct Answer: D

Rationale: Magnetic resonance imaging (MRI) uses high-frequency sound waves to create detailed images of the inside of the body. X-rays (Choice A) use electromagnetic radiation, not sound waves, making it an incorrect choice. A radio antenna (Choice B) is used for communication, not for MRI imaging. Radioisotopes (Choice C) are used in nuclear medicine imaging techniques, not in MRI scans. Therefore, the correct answer is high-frequency sound waves (Choice D) as they are utilized in MRI technology to produce images.

Correct Answer: C

Rationale: Wrinkled and sagging skin is primarily caused by the loss of subcutaneous fat and reduced levels of elastin and collagen in the skin. Choice A is incorrect as drinking too much water does not lead to wrinkled and sagging skin. Choice B is incorrect because heredity alone does not cause this condition. Excess subcutaneous fat, as mentioned in Choice D, can contribute to a different skin appearance, such as puffiness, but not wrinkled and sagging skin.

Correct Answer: A

Rationale: The statement is true. Temperature is a measure of the average kinetic energy of the particles in a substance, while heat is the transfer of energy from a hotter object to a colder one. Heat is not a measurement of the intensity of temperature, but rather the energy transfer due to a temperature difference. Therefore, the correct answer is True. Choice B (False) is incorrect as the statement is true based on the definitions of temperature and heat.

Correct Answer: C

Rationale: The correct answer is 'superficial.' In anatomy, the term 'superficial' refers to a structure that is close to the surface of the body. Choice A, 'anterior,' refers to the front of the body, not specifically to depth. Choice B, 'proximal,' refers to a structure that is closer to the point of attachment or trunk of the body. Choice D, 'superior,' indicates a structure that is above or higher in position.

Correct Answer: A

Rationale: The correct answer is 'tissues, which build organs.' Specialized cell types organize to form tissues, which in turn build organs. Tissues are groups of cells that work together to perform a specific function. Option B is incorrect because organs are composed of tissues, not the other way around. Option C is incorrect as organ systems consist of multiple organs working together, not building tissues. Option D is incorrect as atoms are the basic building blocks of matter and are not directly involved in forming tissues.

Correct Answer: A

Rationale: An anatomist focuses on observing the structure and morphology of body parts, such as organs, tissues, and cells, to understand their organization. On the other hand, a physiologist is more concerned with studying the functions and processes of these body parts, including how they work individually and together to maintain homeostasis. Therefore, the correct answer is 'observing body parts; studying functions of body parts.' Choices B, C, and D are incorrect as they do not accurately reflect the primary activities of anatomists and physiologists.