Which enzyme found in saliva is responsible for breaking down carbohydrates into smaller molecules like sugars?

Correct Answer: B

Rationale: The correct answer is B. Saliva contains an enzyme called amylase, which specifically targets carbohydrates and breaks them down into smaller molecules like sugars. Pepsin, choice A, is an enzyme found in the stomach that breaks down proteins, not carbohydrates. Lipase, choice C, is responsible for breaking down fats, not carbohydrates. Trypsin, choice D, is an enzyme that breaks down proteins in the small intestine, not carbohydrates. Therefore, choices A, C, and D are incorrect for this question.

Correct Answer: B

Rationale: The scrotum is the correct answer, as it is the protective sac surrounding the testes in the male reproductive system. The scrotum's role is crucial in maintaining the optimal temperature for proper sperm production by regulating the distance of the testes from the body. The vas deferens is a duct responsible for transporting sperm from the testes to the urethra, not the protective sac surrounding the testes. The epididymis is a coiled tube where sperm mature and are stored before ejaculation, not the protective sac. The urethra is a tube that serves as a common passageway for both urine and semen to exit the body, not the protective sac surrounding the testes.

Correct Answer: C

Rationale: The lymphatic system and the immune system work closely together to fight infections. The lymphatic system aids the immune system by circulating white blood cells, a crucial component in combating pathogens, throughout the body. This collaboration helps identify and eliminate harmful invaders to maintain the body's health and well-being. Choice A (Respiratory system) is incorrect because while it plays a role in oxygen exchange and removing carbon dioxide, it is not primarily responsible for fighting infections. Choice B (Digestive system) is incorrect as its main functions involve breaking down food and absorbing nutrients, not directly fighting infections. Choice D (Nervous system) is incorrect because its primary role is in transmitting signals throughout the body and controlling bodily functions, not in fighting infections.

Correct Answer: B

Rationale: The correct answer is B: Stomach. The stomach is the muscular pouch in the upper left abdomen that stores food after swallowing and begins mechanical and chemical digestion. It secretes gastric juices containing enzymes and hydrochloric acid to break down food particles. The esophagus is a muscular tube that carries food from the mouth to the stomach, while the small intestine and large intestine are primarily involved in the absorption of nutrients and water, respectively. Therefore, the stomach is the organ responsible for the described functions, making it the correct answer in this context.

Correct Answer: C

Rationale: Consuming sufficient dietary fiber promotes satiety and gut health by adding bulk to the diet, helping with feelings of fullness, and supporting healthy digestion. Additionally, fiber aids in regulating bowel movements and maintaining a healthy gut microbiota, contributing to overall digestive wellness. It does not provide a concentrated source of energy as fiber is not fully digested for energy production, nor does it directly aid in the absorption of vitamins and minerals. Fiber does not break down complex carbohydrates but rather assists in their digestion and absorption by slowing down the process, which helps in maintaining stable blood sugar levels and promoting better overall health.