Q: Q: Generally speaking, electronegativity values ______ from left to right across a row in the periodic table and _______ down a column. Read this paragraph and choose the correct option from the provided answers: The general trend in electronegativity is that the value increases from left to right across a row in the periodic table and decreases down a column. The most electronegative element is fluorine, which has a value of 4.0. As discussed in the lesson "Trends in the Periodic Table," electronegativity increases across a row as the number of protons in the nucleus increases and therefore has a stronger pull. Electronegativity decreases down a column due to an increased effect of electron shielding in larger atoms. Choices: - reverse, descend - move, fall - decrease, increase - increase, decrease A:
A: increase, decrease

Q: Q: Energy is lost as heat between each trophic level due to the second law of what? Read this paragraph and choose the correct option from the provided answers: One major factor that limits the length of food chains is energy. Energy is lost as heat between each trophic level due to the second law of thermodynamics. Thus, after a limited number of trophic energy transfers, the amount of energy remaining in the food chain may not be great enough to support viable populations at yet a higher trophic level. The loss of energy between trophic levels is illustrated by the pioneering studies of Howard T. Odum in the Silver Springs, Florida, ecosystem in the 1940s (Figure 46.5). The primary producers generated 20,819 kcal/m2/yr (kilocalories per square meter per year), the primary consumers generated 3368 kcal/m2/yr, the secondary consumers generated 383 kcal/m2/yr, and the tertiary consumers only generated 21 kcal/m2/yr. Thus, there is little energy remaining for another level of consumers in this ecosystem. Choices: - reactions - particles - chemistry - thermodynamics A:
A: thermodynamics

Q: Q: What organs need constant pressure to filter the blood? Read this paragraph and choose the correct option from the provided answers: The kidneys also need constant pressure to filter the blood. When the blood pressure drops too low, the kidneys increase the pressure. One way is by producing angiotensin, a blood vessel-constricting protein. This protein also signals the body to retain sodium and water. Together, the constriction of blood vessels and retention of sodium and water help restore normal blood pressure. Choices: - lungs - dialysis - arteries - kidneys A:
A: kidneys

Q: Q: What is a random change in an organism's genes? Read this paragraph and choose the correct option from the provided answers: At some time in the past, a variation probably came from a mutation. A mutation is a random change in an organism's genes ( Figure below ). Mutations are natural. Some are harmful, but many are neutral. If a mutation is harmful, the organism may not live to reproduce. If the mutation is beneficial, that organism may have a better chance to survive. An organism that survives is likely to have offspring. If it does, it may pass the mutation on to its offspring. The offspring may be more likely to survive. Choices: - meiosis - infection - accumulation - mutation A:
A: mutation