Problem: While hiking Bob likes to collect plant specimens. Yesterday, he was hiking along a creek, and was specifically looking for epiphytes. Eventually, he found one, and tagged the specimen as specimen A. To compare specimen A with another plant he collected another plant specimen that was not an epiphyte. He tagged that specimen as specimen B. Which specimen would most probably grow on the ground, specimen A or specimen B? Hint: Plants called epiphytes grow on other plants. They obtain moisture from the air and make food by photosynthesis. Most epiphytes are ferns or orchids that live in tropical or temperate rainforests (see Figure below ). Host trees provide support, allowing epiphyte plants to obtain air and sunlight high above the forest floor. Being elevated above the ground lets epiphytes get out of the shadows on the forest floor so they can get enough sunlight for photosynthesis. Being elevated may also reduce the risk of being eaten by herbivores and increase the chance of pollination by wind.

A: specimen B

Problem: Mark is a biologist. He is trying to see how to make chemical reactions within organism easier. To that end, he conducts two tests, test A an test B, on an organism. In test A he reduces catalysts from the organism, but in test B he induces catalysts in the organism. He needs to observe the outcomes of these tests. Which test would see reactants colliding less, test A or test B? Hint: Most chemical reactions within organisms would be impossible under the conditions in cells. For example, the body temperature of most organisms is too low for reactions to occur quickly enough to carry out life processes. Reactants may also be present in such low concentrations that it is unlikely they will meet and collide. Therefore, the rate of most biochemical reactions must be increased by a catalyst. A catalyst is a chemical that speeds up chemical reactions. In organisms, catalysts are called enzymes . Essentially, enzymes are biological catalysts.

A: test A

Problem: Mark is a biologist. He is trying to see how to make chemical reactions within organism easier. To that end, he conducts two tests, test A an test B, on an organism. In test A he reduces catalysts from the organism, but in test B he induces catalysts in the organism. He needs to observe the outcomes of these tests. Which test would see reactants colliding more, test A or test B? Hint: Most chemical reactions within organisms would be impossible under the conditions in cells. For example, the body temperature of most organisms is too low for reactions to occur quickly enough to carry out life processes. Reactants may also be present in such low concentrations that it is unlikely they will meet and collide. Therefore, the rate of most biochemical reactions must be increased by a catalyst. A catalyst is a chemical that speeds up chemical reactions. In organisms, catalysts are called enzymes . Essentially, enzymes are biological catalysts.

A: test B

Problem: Rob is competing in a cross country race. After running about a mile he reached a place with two signs, sign A and sign B. Sign A says that it's a quicksand. But sign B says that it's not a quicksand. He has to decide which way to go. Which way would most probably have liquefied soil, sign A or sign B? Hint: Quicksand forms in saturated loose sand when the sand is suddenly agitated. When water in the sand cannot escape, it creates a liquefied soil that loses strength and cannot support weight. Quicksand can form in standing water or in upwards flowing water (as from an artesian spring). In the case of upwards flowing water, forces oppose the force of gravity and suspend the soil particles. The saturated sediment may appear quite solid until a sudden change in pressure or shock initiates liquefaction. This causes the sand to form a suspension and lose strength. The cushioning of water gives quicksand, and other liquefied sediments, a spongy, fluid-like texture. Objects in liquefied sand sink to the level at which the weight of the object is equal to the weight of the displaced soil/water mix and the submerged object floats due to its buoyancy.

A:
sign A