Which part of the brain is responsible for higher brain functions, such as thought and action?

Correct Answer: D

Rationale: The cerebrum is the correct answer as it is responsible for higher brain functions like thought and action. The amygdala (Choice A) is involved in emotions and emotional responses, not higher brain functions. The brain stem (Choice B) controls basic life functions such as breathing and heart rate, not higher brain functions. The cerebellum (Choice C) is mainly responsible for motor control and coordination, not higher brain functions like thought and action.

Correct Answer: D

Rationale: The correct answer is D: 'Takes shape of container.' Liquids exhibit the property of taking the shape of their container while maintaining a fixed volume. This is due to the ability of liquid particles to flow and move freely within the container. Choices A, B, and C are incorrect. Choice A, 'High atomic attraction,' is not a general property of liquids as the level of attraction between liquid particles can vary. Choice B, 'Fixed volume,' is partially correct as liquids do have a fixed volume, but they do not have a fixed shape. Choice C, 'Low pressure,' is not a defining property of liquids.

Correct Answer: B

Rationale: Hydrophobic proteins are known for their ability to repel water and are often involved in providing structural support in cells and tissues. They help maintain the structural integrity and shape of cell membranes, organelles, and other cellular components. Choice A, digestive enzymes, typically consist of hydrophilic proteins that interact with water and substrates to facilitate digestion. Choice C, carrying oxygen molecules, is a function commonly associated with specific proteins like hemoglobin. Choice D, storing energy, is usually performed by proteins like enzymes involved in energy storage and release, such as glycogen phosphorylase.

Correct Answer: A

Rationale: The correct answer is A: Femur. Long bones are characterized by their elongated shape, with examples including the femur, humerus, and tibia. These bones are essential for support, movement, and bone marrow production. Choice B, 'Ribs and cranial bones,' consists of flat bones, not long bones. Choice C, 'Sesamoid,' refers to small bones embedded within tendons and do not fall under the category of long bones. Choice D, 'Vertebrae and hip bones,' includes irregular bones that provide structural support and protection for vital organs, but they are not classified as long bones.

Correct Answer: D

Rationale: Keratin is a structural protein found in hair, skin, and nails, providing strength and protection. It forms the main structural component of hair, making choice D the correct answer. Choices A, B, and C are incorrect because keratin is not an enzyme released by the stomach, not released in the neuromuscular junction, and not found in the hypodermis. Remember that keratin is primarily associated with structural support in epithelial cells.

Correct Answer: B

Rationale: The rib cage plays a crucial role in protecting vital organs, specifically the lungs and heart, from external injuries. Choice A is incorrect because the rib cage does not primarily protect the digestive organs. Choice C is incorrect as the primary function of the rib cage is not to support movement, but to protect internal organs. Choice D is incorrect as regulating body temperature is not a function typically associated with the rib cage.

Correct Answer: D

Rationale: Ventilation is the correct answer as it specifically refers to the mechanical process of breathing air in and out of the lungs. Diffusion (choice A) is the movement of molecules from an area of high concentration to low concentration, not related to the mechanical act of breathing. Perfusion (choice B) is the process of blood flow through the tissues and organs, not directly related to breathing mechanically. Respiration (choice C) involves the exchange of oxygen and carbon dioxide at the cellular level, different from the mechanical act of breathing.

Correct Answer: B

Rationale: The correct answer is B: 'To secrete digestive enzymes.' The pancreas plays a crucial role in digestion by secreting digestive enzymes that break down carbohydrates, proteins, and fats. This process aids in the breakdown of food into nutrients that can be absorbed by the small intestine. Choices A, C, and D are incorrect because the pancreas is not responsible for secreting bile (liver and gallbladder function), absorbing nutrients (small intestine function), or transporting waste (colon function) in the digestive system.

Correct Answer: C

Rationale: Natural Killer cells are a crucial component of the innate immune response. They play a significant role in defending against infected or cancerous cells through their ability to identify and kill abnormal cells. B-cells (Choice A) and Cytotoxic T-cells (Choice B) are part of the adaptive immune response, which involves a more specific and targeted response to pathogens. Antigen-Presenting Cells (Choice D) are also part of the adaptive immune response, where they present antigens to activate other immune cells.