What is the role of the kidneys in the body?

Correct Answer: B

Rationale: The correct answer is B: To filter waste from the blood. The kidneys play a crucial role in filtering waste products and excess substances from the blood to form urine, which helps maintain fluid balance and eliminate toxins from the body. Choice A is incorrect because regulating body temperature is primarily controlled by the skin and other mechanisms. Choice C is incorrect as hormone production is mainly attributed to other organs like the endocrine glands. Choice D is incorrect as the transportation of oxygen is primarily facilitated by the lungs and circulatory system, not the kidneys.

Correct Answer: C

Rationale: The correct answer is C, Nucleus. The nucleus is responsible for storing genetic information in the form of DNA. The DNA within the nucleus controls the activities of the cell by directing the synthesis of proteins and regulating gene expression. Choices A, Ribosome, B, Mitochondrion, and D, Cytoplasm, do not store genetic information. Ribosomes are involved in protein synthesis, mitochondria produce energy for the cell, and cytoplasm is a gel-like substance that houses organelles and where many cellular activities occur.

Correct Answer: B

Rationale: The correct answer is B: Alveoli. Alveoli are tiny air sacs in the lungs where gas exchange occurs. Oxygen from inhaled air diffuses into the bloodstream, while carbon dioxide from the blood is released into the alveoli to be exhaled. The trachea (Choice A) is the windpipe that carries air to and from the lungs, but it is not involved in gas exchange. Bronchioles (Choice C) are small air passages within the lungs that branch off from the bronchi, leading air to the alveoli but not directly involved in gas exchange. The diaphragm (Choice D) is a muscle below the lungs that helps in breathing by expanding and contracting the chest cavity, but it is not the site of gas exchange.

Correct Answer: B

Rationale: The correct answer is B: 'To filter waste from the blood.' The kidneys are vital organs responsible for filtering waste products from the blood, regulating fluid and electrolyte balance, and producing urine. Choice A is incorrect because the production of digestive enzymes primarily occurs in the pancreas and salivary glands. Choice C is incorrect as the production of white blood cells mainly takes place in the bone marrow and lymphatic system. Choice D is incorrect as the production of red blood cells occurs in the bone marrow.

Correct Answer: B

Rationale: The correct answer is B: Sebaceous gland. Sebaceous glands are responsible for producing oil (sebum) that keeps the skin and hair moisturized. Sudoriferous glands produce sweat, not oil, and are involved in temperature regulation. Hair follicles are responsible for hair growth and do not produce oil directly. Melanocytes are cells responsible for producing melanin, the pigment that gives skin its color, and are not involved in oil production.