Cores of coral reefs show a reef base that is well below the photic zone. How are two ways that is this possible, given the light limitations of reef-forming corals?
What will be an ideal response?
The fact that cores of coral reefs are found well below the photic zone is strong evidence for the subsidence of oceanic crusts with time or for rising sea levels after the last glacial period. The base of these reefs were, at one point, within the photic region of the ocean. As sea levels rose, or as the crust beneath the reef sank, the platform of many reefs fell below the coral platform and the upper reaches of the reef continued to grow in order to keep up with increasing water depths.
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The ultimate source of energy for humans comes from what source?
A. The sun B. Plants C. Water D. Air E. Animals
After removing some freshly baked cookies from the oven, you accidentally brush the side of the pan with your bare hand. Your reflexes kick in and you immediately draw your hand away. What is the proximate cause of this behavior?
A. Drawing your hand away quickly when it encounters high heat prevents injury, thereby increasing your chances to survive and reproduce. B. For millions of years, your ancestors survived in part because they avoided damaging heat, and thus were able to pass on heat-avoiding genes to you. C. You perceived the heat, judged that it would cause a burn if you left your hand in place too long, and made a conscious decision to pull your hand away. D. Sensory receptors in the skin of your hand sent a signal to interneurons in your spinal cord, which subsequently signaled the motor neurons in your arm and hand to contract, drawing your hand away.
As a result of global warming,
A) forests are expanding in range. B) there are greater extremes in weather patterns. C) the ozone layer is becoming thicker. D) species are becoming active later in the spring. E) species' ranges are shifting toward the equator.
The secondary oocyte does not complete the second meiotic division until
A. fertilization. B. ovulation. C. birth. D. puberty.