Practice Science TEAS Test

Correct Answer: A

Rationale: The correct answer is A: Kidneys. The kidneys are responsible for filtering waste products, excess fluids, and toxins from the blood to form urine. Step-by-step rationale: 1. The kidneys contain millions of tiny filtering units called nephrons. 2. Blood flows through the nephrons, where waste products are removed and urine is formed. 3. The urine then flows through the ureters to the bladder for storage and eventual elimination. Other choices are incorrect because: B: Pancreas - produces digestive enzymes and regulates blood sugar, not primarily involved in waste filtration. C: Liver - detoxifies chemicals, produces bile, and stores nutrients, but not the primary organ for blood filtration. D: Heart - pumps blood and circulates it throughout the body, not directly involved in waste filtration.

Correct Answer: C

Rationale: The correct answer is C: Small intestine. The small intestine is responsible for absorbing nutrients due to its large surface area lined with villi and microvilli, which increase absorption capacity. It also contains enzymes and bile to further break down and facilitate nutrient absorption. The other choices are incorrect because the esophagus is a tube that transports food to the stomach, the stomach mainly digests food using acid and enzymes, and the large intestine absorbs water and electrolytes, not nutrients.

Correct Answer: B

Rationale: The correct answer is B: Gene. A gene is a smaller unit of genetic information than a chromosome. Chromosomes contain many genes, so they are larger in scale. The genome (option A) refers to the complete set of an organism's genetic material, which includes all the chromosomes. DNA (option C) is the genetic material that makes up chromosomes and genes. Option D is incorrect because while all the listed choices are related to genetics, genes are specifically smaller than chromosomes.

Correct Answer: B

Rationale: The correct answer is B: Liver. The liver is responsible for producing bile, which helps in the digestion and absorption of fats. It is stored in the gallbladder (not produced by it), which releases it into the small intestine when needed. The pancreas produces digestive enzymes and insulin, not bile. The stomach produces gastric juices, not bile. In summary, the liver is the primary organ responsible for bile production, making it the correct choice.

Correct Answer: C

Rationale: The correct answer is C: Iron (II). In heme, the central cation is Iron (II) because it forms a coordination complex with the porphyrin ring. Iron (II) has a +2 charge, allowing it to bind to the nitrogen atoms in the porphyrin ring. This binding is crucial for the proper functioning of heme in carrying oxygen in hemoglobin. Choice A (Cr III) is incorrect because chromium (III) does not typically bind to porphyrin rings in heme. Choice B (Cu II) is incorrect because copper (II) is not commonly found at the center of heme. Choice D (Iron III) is incorrect because in heme, iron is usually in the +2 oxidation state to efficiently bind and release oxygen. Iron (III) is not as effective in this role.