1 Which of the following is an essential element in plants?A) Nitrogen B) Nickel C) Aluminum D) Lead 2 Choose the correct order of soil horizons in a soil profile starting from surface level.A) Leaching zone, living organisms and humus, weathered rock, subsoil B) Humus, weathered rock, leaching zone C) Weathered rock, subsoil, topsoil D) Topsoil, subsoil, weathered rock 3 A soil with mostly _____ particles has large spaces and the water drains right through them.A) silt B) sand C) clay 4 The final decomposition of organic remains in humus to inorganic nutrients is performed by _____.A) microorganisms B) earthworms C) small plants D) insects 5 Which of the following is a micronutrient?A) Iron B) Potassium C) Carbon D) Calcium 6 A small pore in the leaf epidermis which is bordered by guard cells is a:A) tracheid. B) sieve-tube element. C) root hair. D) stoma. 7 Root pressure may be responsible for _____ when drops of water are forced out of vein endings along the edges of the leaves.A) transpiration B) erosion C) guttation D) girdling 8 The mechanism for xylem transport of water is explained by the _____ model.A) cohesion-tension B) endosymbiotic C) fluid mosaic D) pressure flow 9 Xylem is composed of what two types of conducting cells?A) Companion cells and collenchyma B) Vessel elements and tracheids C) Seive tube members and companion cells D) Cork and palisade parenchymal cells 10 Sieve tube elements are connected to one another by _____ to form a continuous pipeline for sugars.A) gap junctions B) adhesion junctions C) strands of cytoplasma within plasmodesmata D) lignin within the cell walls 11 An accumulation of _____ ions within guard cells causes the stomata to open.A) calcium B) fluorine C) potassium D) chlorine 12 Bacteria living in root nodules receive _____ from the plant and furnish _______ to their hosts.A) nitrogen compounds; carbohydrates B) carbohydrates; nitrogen compounds C) oxygen; carbon dioxide D) potassium; hydrogen ions 13 Minerals are transported upwards from the roots in _____.A) xylem B) phloem C) the casparian strip 14 Nonphotosynthetic plants _____.A) obtain their organic compounds from aerobic respiration B) are parasitic, deriving their carbohydrates from other plants and/or fungi C) do not require organic compounds to maintain life. D) capture their energy from the sun and reduce carbon dioxide 15 The pressure-flow model is an explanation for the ______.A) movement of organic materials in phloem B) movement of H2O in xylem C) movement of minerals in xylem 16 The _____ form a continuous pipeline from a source to a sink.A) sieve tubes B) vessel elements C) tracheids D) stomates 17 Which of these statements about phytoremediation is NOT true?A) It occurs at a slow pace. B) It can only be effective at reaching contaminants at the root level. C) It is expensive and requires excessive energy to accomplish. D) Plants vary in their ability to remove pollutants from the environment. 18 Scientists have suggested the planting of ____________ may help reduce the levels of selenium.A) canola B) poplars C) mustard plants D) wheat 19 All of the following statements about the pressure-flow model of phloem transport are true EXCEPT:A) The direction of flow is from the source to the sink. B) The buildup of water creates a positive pressure that accounts for flow of phloem contents. C) Transpiration exerts a pulling force that moves the phloem contents. D) Sugar is actively transported into the phloem, followed by osmosis of water. 20 Which chemical properties of water are important to the movement of xylem sap?A) Cohesion and adhesion B) Surface tension and high specific heat C) The ability to maintain temperature and nonpolarity of its molecules