Question: Q: What feature of the spine helps with flexibility and strength? Read this paragraph and choose the correct option from the provided answers: Curvatures of the Vertebral Column The adult vertebral column does not form a straight line, but instead has four curvatures along its length (see Figure 7.20). These curves increase the vertebral column's strength, flexibility, and ability to absorb shock. When the load on the spine is increased, by carrying a heavy backpack for example, the curvatures increase in depth (become more curved) to accommodate the extra weight. They then spring back when the weight is removed. The four adult curvatures are classified as either primary or secondary curvatures. Primary curves are retained from the original fetal curvature, while secondary curvatures develop after birth. Choices: - shape - angle - arrangement - curves A:
Answer: curves

Question: Q: What moves nitrogen back and forth between the atmosphere and organisms? Read this paragraph and choose the correct option from the provided answers: The nitrogen cycle moves nitrogen back and forth between the atmosphere and organisms. Choices: - the calcium cycle - the Krebs cycle - the leakage cycle - the nitrogen cycle A:
Answer: the nitrogen cycle

Question: Q: What are solutions that maintain a relatively constant ph when an acid or a base is added? Read this paragraph and choose the correct option from the provided answers: Buffers are solutions that maintain a relatively constant pH when an acid or a base is added. They therefore protect, or "buffer," other molecules in solution from the effects of the added acid or base. Buffers contain either a weak acid (HA) and its conjugate base (A) or a weak base (B) and its conjugate acid (BH+), and they are critically important for the proper functioning of biological systems. In fact, every biological fluid is buffered to maintain its physiological pH. Choices: - gases - water - liquids - buffer A:
Answer:
buffer