1 Which statement accurately compares cells in the human circulatory system to cells in the human nervous system?

(1) Cells in the circulatory system carry out the same life function for the organism as cells in the nervous system.
(2) Cells in the circulatory system are identical in structure to cells in the nervous system.
(3) Cells in the nervous system are different in structure from cells in the circulatory system, and they carry out different specialized functions.
(4) Cells in the nervous system act independently, but cells in the
circulatory system function together.

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2 An iodine test of a tomato plant leaf revealed that starch was present at 5:00 p.m. on a sunny afternoon in July. When a similar leaf from the same tomato  plant  was tested with iodine at 6:00 a.m. the next morning, the test indicated that less starch was present. This reduction in starch content most likely occurred because starch was

(1) changed directly into proteins
(2) transported out of the leaves through the guard cells
(3) transported downward toward the roots through tubes
(4) changed into simple sugars

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3 Luciferin is a molecule that, when broken down in fireflies, produces heat and light. The rate at which luciferin is broken down in cells is controlled by

(1) a carbohydrate        (3) an enzyme
(2) a simple sugar         (4) a complex fat

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4 Communication between cells is affected if there is decreased ability to produce

(1) digestive enzymes and gametes
(2) antibodies and chloroplasts
(3) hormones and nerve impulses
(4) antibiotics and guard cells

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5 Tomato plants in a garden are not growing well. The gardener hypothesizes that the soil is too acidic. To test this hypothesis accurately, the gardener could

(1) plant seeds of a different kind of plant
(2) move the tomato plants to an area with less sunlight
(3) change the pH of the soil
(4) reduce the amount of water available to the plant

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