Elements of Ecology, 8e (Smith/Smith) Chapter The Aquatic Environment 3.1 Short Answer Questions 1) The process by which water travels in a sequence from the air to Earth and returns to the atmosphere is referred to as the cycle Answer: water hydrologic Topic: Section 3.1 2) The total amount of evaporating water from the surfaces of the ground and vegetation is called Answer: evapotranspiration Topic: Section 3.1 3) The of water is the amount of heat that is required to raise the temperature of water one degree Celsius Answer: specific heat Topic: Section 3.2 4) Small animals, such as water striders and water spiders, can run across a pond's surface due to Answer: surface tension Topic: Section 3.2 5) is the source of frictional resistance to objects moving through water Answer: Viscosity Topic: Section 3.2 6) As sunlight passes through water, only wavelengths are able to penetrate into deeper water Answer: blue Topic: Section 3.3 7) The region of the vertical depth profile where the temperature declines most rapidly is called the Answer: thermocline Topic: Section 3.4 8) The upper layer of warm, low-density water of an open body of water is called the Answer: epilimnion Topic: Section 3.4 9) A liquid that is a homogeneous mixture of two or more substances is called a Answer: solution Topic: Section 3.5 Copyright © 2012 Pearson Education, Inc 10) The movement of molecules from an area of high concentration to an area of low concentration is called Answer: diffusion Topic: Section 3.6 11) The solubility of oxygen as water warms Answer: decreases Topic: Section 3.6 12) In the open ocean, concentrations of oxygen reach a minimum value of 500—1000 m, a region referred to as the oxygen Answer: minimal zone Topic: Section 3.6 13) The abundance of hydrogen ions in solution is a measure of Answer: acidity Topic: Section 3.7 14) solutions are those that have a higher concentration of OH- (hydroxyl ions) than H+ ions Answer: Alkaline Topic: Section 3.7 15) Aquatic organisms are unable to tolerate low pH conditions largely because acidic waters contain high concentrations of Answer: aluminum Topic: Section 3.7 16) A region of occurs where deep waters of the ocean move upward to the surface Answer: upwelling Topic: Section 3.8 17) The physical movements of water caused by the gravitational pull of the Sun and the Moon are called Answer: tides Topic: Section 3.9 18) The area lying between the water lines of high and low tide is referred to as the Answer: intertidal zone Topic: Section 3.9 19) The place where freshwater streams and rivers meet the sea and mix with saltwater is called a(n) Answer: estuary Topic: Section 3.10 Copyright © 2012 Pearson Education, Inc 20) An underground layer of permeable, water-bearing substrate is known as a(n) Answer: aquifer Topic: Ecological Issues: Groundwater Resources 3.2 Multiple-Choice Questions 1) About 75% of the Earth's surface is covered by A) water B) bare ground C) forest D) grassland Answer: A Topic: Introduction to Chapter 2) The energy driving the global water cycle is provided by A) wind B) tides C) rotation of the Earth on its axis D) solar energy Answer: D Topic: Section 3.1 3) The evaporation of water from internal surfaces of leaves, stems, and other living parts of a plant is called A) osmosis B) transpiration C) diffusion D) infiltration Answer: B Topic: Section 3.1 4) Most of Earth's water resides in A) the oceans B) the polar ice caps and glaciers C) freshwater lakes, ponds, rivers, and streams D) groundwater Answer: A Topic: Section 3.1 5) The individual atoms of a water molecule are held together by A) ionic bonds B) hydrogen bonds C) covalent bonds D) weak bonds Answer: C Topic: Section 3.2 Copyright © 2012 Pearson Education, Inc 6) Water takes longer than air to warm up or cool off because of water's high A) specific heat B) viscosity C) surface tension D) density Answer: A Topic: Section 3.2 7) The density of water is greatest at A) -4°C B) 0°C C) 4°C D) 100°C Answer: C Topic: Section 3.2 8) The streamlined body shape of many aquatic organisms that swim helps reduce frictional resistance caused by water's high A) buoyancy B) viscosity C) surface tension D) density Answer: B Topic: Section 3.2 9) Aquatic organisms generally require less structural support (e.g., skeletons) due to water's high A) specific heat B) buoyancy C) surface tension D) viscosity Answer: B Topic: Section 3.2 10) As light enters water, the last wavelengths absorbed are A) red wavelengths B) yellow wavelengths C) green wavelengths D) blue wavelengths Answer: D Topic: Section 3.3 Copyright © 2012 Pearson Education, Inc 11) An organism that lives in a deep marine environment may exhibit all the following physical characteristics, except A) large eyes B) bioluminescence C) colorful skin pigmentation D) streamlined body Answer: C Topic: Sections 3.2 and 3.3 12) The upper layer of warm, less dense water is referred to as the A) thermocline B) hypolimnion C) epilimnion D) benthic zone Answer: C Topic: Section 3.4 13) A scientist measures the temperature of a lake at various depths and finds very little variation between temperatures at the surface and at the bottom of the lake The temperature measurements were most likely taken in a A) temperate lake during summer B) temperate lake during winter C) tropical lake during summer D) tropical lake during winter Answer: B Topic: Section 3.4 14) The depth of a thermocline is directly influenced by all the following factors, except A) wind speed B) wave action C) input of solar radiation D) influx of water Answer: D Topic: Section 3.4 15) In comparison with the epilimnion of a lake, the water of the hypolimnion is A) warmer B) less dense C) cooler D) more oxygenated Answer: C Topic: Sections 3.4 and 3.6 Copyright © 2012 Pearson Education, Inc 16) The purest form of water containing the fewest solutes occurs in A) clouds B) surface water C) groundwater D) precipitation Answer: A Topic: Section 3.5 17) Concentrations of solutes are greatest in A) springs B) rivers C) lakes D) oceans Answer: D Topic: Section 3.5 18) The primary ions that contribute to the salinity of ocean waters are A) calcium and sodium B) sodium and chloride C) sodium and carbonate D) calcium and chloride Answer: B Topic: Section 3.5 19) Molecules spontaneously move from an area of higher concentration to an area of lower concentration in a process known as A) conduction B) solution C) evaporation D) diffusion Answer: D Topic: Section 3.6 20) The primary sources of oxygen in a water body are the atmosphere and A) decomposition B) evaporation C) photosynthesis D) respiration Answer: C Topic: Section 3.6 Copyright © 2012 Pearson Education, Inc 21) A solution with a pH of A) is more alkaline than a solution with a pH of B) has a higher concentration of OH- than a solution with a pH of C) is neutral D) is more acidic than a solution with a pH of 3.5 Answer: A Topic: Section 3.7 22) Aquatic organisms are unable to tolerate low pH conditions mainly because acidic waters contain high concentrations of toxic A) sodium B) chlorine C) aluminum D) carbon dioxide Answer: C Topic: Section 3.7 23) The density of seawater increases when A) temperature and salinity decrease B) temperature and salinity increase C) temperature increases and salinity decreases D) temperature decreases and salinity increases Answer: D Topic: Section 3.8 24) Tides are strongest when the A) body of water is very large B) Sun is setting C) Earth, Moon, and Sun are in line D) Moon and Sun are at right angles to the Earth Answer: C Topic: Section 3.9 25) A tide occurs when the Moon and Sun are at right angles to the Earth A) low B) high C) spring D) neap Answer: D Topic: Section 3.9 Copyright © 2012 Pearson Education, Inc 26) Daily and seasonal fluctuations in temperature, salinity, and dissolved gases are most extreme in A) the intertidal zone B) sandy beaches C) the estuary D) the open ocean Answer: C Topic: Sections 3.9 and 3.10 27) Salinity within an estuary is greatest in A) surface water at high tide B) surface water at low tide C) deep water at high tide D) deep water at low tide Answer: D Topic: Section 3.10 28) An aquifer refers to A) an intermittent spring that flows during only part of the year B) a layer of water-bearing permeable rock, sand, or gravel C) any body of freshwater D) the cool, dense layer of water at the bottom of a body of water Answer: B Topic: Ecological Issues: Groundwater Resources 3.3 True/False Questions 1) The rotation of Earth on its axis is the driving force behind the water cycle Answer: FALSE Topic: Section 3.1 2) The turnover rate of water is longer in the ocean than in the atmosphere Answer: TRUE Topic: Section 3.1 3) Individual atoms within water molecules are held together by covalent bonds Answer: TRUE Topic: Section 3.2 4) Temperature fluctuates more in aquatic habitats than in terrestrial habitats Answer: FALSE Topic: Section 3.2 5) The viscosity of water is less than the viscosity of air Answer: FALSE Topic: Section 3.2 Copyright © 2012 Pearson Education, Inc 6) Of the visible light spectrum, blue wavelengths penetrate the deepest into water Answer: TRUE Topic: Section 3.3 7) The thermocline is permanent in tropical bodies of water and seasonal in temperate bodies of water Answer: TRUE Topic: Section 3.4 8) In lakes and ponds of temperate latitudes, the upper and bottom layers of water usually turn over as water warms up during spring Answer: FALSE Topic: Section 3.4 9) Saltwater has a higher concentration of solutes than freshwater Answer: TRUE Topic: Section 3.5 10) Cold water contains more oxygen than warm water Answer: TRUE Topic: Section 3.6 11) During summer, the amount of oxygen in the water is greatest at the bottom of ponds and lakes Answer: FALSE Topic: Section 3.6 12) A high pH indicates a very acidic solution Answer: FALSE Topic: Section 3.7 13) Aluminum is toxic to many aquatic species Answer: TRUE Topic: Section 3.7 14) Upwelling occurs in the equatorial waters of the ocean Answer: TRUE Topic: Section 3.8 15) The Sun has a stronger effect than the Moon on tides Answer: FALSE Topic: Section 3.9 16) Tides are highest and lowest during a spring tide, when the Sun and Moon are aligned with the Earth Answer: TRUE Topic: Section 3.9 Copyright © 2012 Pearson Education, Inc 17) Salinity is higher in an estuary than in the ocean Answer: FALSE Topic: Section 3.10 18) Aquifers, like the High Plains Ogallala aquifer, provide a limitless supply of water Answer: FALSE Topic: Ecological Issues: Groundwater Resources 3.4 Essay Questions 1) Describe the water or hydrologic cycle and explain how water arrives at various reservoirs where it is stored Topic: Section 3.1 2) Explain how differences in the viscosity of water and air affect the biology of plants and animals living in aquatic and terrestrial environments Topic: Section 3.2 3) Describe several adaptations that organisms have developed in response to the minimal light environments in deep water Topic: Section 3.3 4) Explain how temperature, density, and oxygen concentrations vary with depth in large bodies of water Topic: Sections 3.4 and 3.6 5) Explain why water can dissolve more substances than any other liquid Furthermore, explain the importance of this property to life on Earth Topic: Section 3.5 6) Explain how the pH of an aquatic environment can influence the organisms that live in or around the water body Topic: Section 3.7 7) Describe the causes of oceanic upwelling Topic: Section 3.8 8) Explain how tides form and why tidal heights vary over time Topic: Section 3.9 9) Define an estuary, and describe how gradients in salinity are maintained Topic: Section 3.10 10) Discuss the importance of the High Plains Ogallala aquifer to agriculture in the United States Topic: Ecological Issues: Groundwater Resources 10 Copyright © 2012 Pearson Education, Inc