Which mineral is considered an antioxidant?

Correct Answer: A

Rationale: Selenium is the correct answer. It is considered an antioxidant mineral that plays a crucial role in protecting cells from damage caused by free radicals. Selenium is an essential component of the body's antioxidant defense system, promoting overall health and well-being. Calcium (Choice B), Sulfur (Choice C), and Iron (Choice D) are not typically classified as antioxidant minerals. While these minerals have other important functions in the body, they do not primarily act as antioxidants like selenium.

Correct Answer: C

Rationale: The circulatory system works with the digestive system by transporting absorbed nutrients through the body. After digestion occurs in the digestive system, nutrients are absorbed into the bloodstream. The circulatory system then carries these nutrients to cells throughout the body where they are used for energy, growth, and repair. This process ensures that the necessary nutrients are delivered to where they are needed in the body. Choices A, B, and D are incorrect because the circulatory system is not responsible for removing undigested solids, filtering and collecting digested materials, or releasing enzymes that control digestion. These functions are primarily carried out by the digestive system.

Correct Answer: C

Rationale: Tofu is a plant-based source of protein that can provide a significant amount of protein to a person on a vegan diet. It is made from soybeans and is a versatile ingredient that can be used in various dishes to increase protein intake. Tofu is a good option for vegans looking to meet their protein needs. Eggs and fish are not suitable for a vegan diet as they are animal products. While leafy greens do contain some protein, they are not considered a significant protein source compared to tofu.

Correct Answer: C

Rationale: The correct answer is C: frontal. The coronal plane of the body is also known as the frontal plane. This plane divides the body into front (anterior) and back (posterior) sections. It is perpendicular to the sagittal plane and divides the body into front and back portions. The term 'coronal' is often used in radiology and anatomy to describe this specific anatomical plane. Choices A, B, and D are incorrect because the sagittal plane divides the body into left and right portions, the median plane is another name for the sagittal plane, and the axial plane is a term less commonly used to describe an anatomical plane.

Correct Answer: C

Rationale: The correct answer is C: Columnar Epithelium. Columnar epithelium is characterized by tall, pillar-like cells that are closely packed together. This arrangement allows for absorption and secretion in tissues like the digestive tract, where this type of epithelium is commonly found. Squamous epithelium (choice A) consists of flat cells, cuboidal epithelium (choice B) has cube-shaped cells, and transitional epithelium (choice D) is found in areas that need to stretch and expand, like the urinary bladder.

Correct Answer: D

Rationale: The sebaceous glands are a component of the integumentary system, which includes the skin, hair, nails, and associated structures. Sebaceous glands are typically found throughout the skin and are responsible for producing an oily substance called sebum, which helps keep the skin and hair lubricated and moisturized. The endocrine system (Choice A) consists of glands that produce hormones, the digestive system (Choice B) is responsible for processing food, and the respiratory system (Choice C) is involved in breathing and gas exchange.

Correct Answer: C

Rationale: The correct answer is C: 26. The human foot consists of 26 bones, including tarsal bones, metatarsal bones, and phalanges. These bones collaborate to offer support, flexibility, and stability for various activities like standing, walking, and running. Choice A (6) is incorrect as it is too low for the number of bones in the human foot. Choice B (16) is incorrect as it underestimates the actual number of bones in the foot. Choice D (36) is incorrect as it overestimates the number of bones in the human foot.

Correct Answer: A

Rationale: Gallstones become most problematic when they block a duct, such as the bile duct or cystic duct. This blockage can lead to various complications, including inflammation, infection, and even damage to the gallbladder or liver. In severe cases, a blocked duct can cause intense pain, jaundice, and other serious symptoms that require medical intervention. Choices B, C, and D are incorrect because the presence of cholesterol or bilirubin in gallstones or the process of dissolution do not necessarily indicate when gallstones become most problematic. The critical issue arises when the stones obstruct a duct, leading to complications.

Correct Answer: D

Rationale: Melatonin is the hormone produced by the pineal gland. It plays a crucial role in regulating the sleep-wake cycle and is instrumental in maintaining the body's circadian rhythm. Melatonin production is triggered by darkness and inhibited by light, aiding in signaling the body when it is time to sleep. Corticosteroid, oxytocin, and prolactin are hormones produced by other glands in the body and are not associated with the pineal gland. Therefore, they are incorrect choices for this question.