Q: What property of carbon and other elements can be used to date fossils and rocks, among other things? Read this paragraph and choose the correct option from the provided answers: Carbon-14 has a relatively short half-life. It decays quickly compared to some other unstable isotopes. So carbon-14 dating is useful for specimens younger than 50,000 years old. That's a blink of an eye in geologic time. But radiocarbon dating is very useful for more recent events. One important use of radiocarbon is early human sites. Carbon-14 dating is also limited to the remains of once-living things. To date rocks, scientists use other radioactive isotopes. Choices: - mass - full-life - magnetic force - half-life A:
half-life

Q: What is the term for a very rapid motor response that is not directed by the brain? Read this paragraph and choose the correct option from the provided answers: The somatic nervous system also controls some unconscious movements called reflexes. A reflex is a very rapid motor response that is not directed by the brain. In a reflex, nerve impulses travel to and from the spinal cord in a reflex arc, like the one in Figure below . In this example, the person jerks his hand away from the flame without any conscious thought. It happens unconsciously because the nerve impulses bypass the brain. Choices: - instinct - adaptation - sensor - reflex A:
reflex

Q: Gene expression is regulated primarily at the what level? Read this paragraph and choose the correct option from the provided answers: Gene expression is regulated primarily at the transcriptional level. Choices: - manufacturing - translational - binding - transcriptional A:
transcriptional

Q: What is corrosive mixture is formulated by the combination of water, air and sulfur? Read this paragraph and choose the correct option from the provided answers: Surface mining exposes minerals that were underground to air and water at the surface. These minerals contain the chemical element sulfur. Sulfur mixes with air and water to make sulfuric acid. This acid is a highly corrosive chemical. Sulfuric acid gets into nearby streams and can kill fish, plants, and animals. Surface mining is safer for the miners. Choices: - nitric acid - sulfuric water - hydrochloric acid - sulfuric acid A:
sulfuric acid