Question 1

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

Accepted Answer

In temperate lakes during winter, the water column undergoes a process called "turnover," where the water becomes isothermal (uniform temperature) from top to bottom due to mixing caused by winds and changes in density. This would result in very little variation in temperature between the surface and the bottom of the lake. In contrast, tropical lakes typically have a stratified water column, where the surface water is warmer than deeper water, and this stratification is maintained throughout the year, making option C less likely.

Question 2

The purest form of water containing the fewest solutes occurs in

Accepted Answer

Clouds consist of condensed water vapor, making the water in clouds very pure compared to other sources, as it has not yet mixed with contaminants found in surface or groundwater.

Question 3

The primary ions that contribute to the salinity of ocean waters are

Accepted Answer

The most common ions in seawater are sodium and chloride, which together form salt (sodium chloride). Calcium and carbonate are also present in seawater, but in much lower concentrations compared to sodium and chloride.

Question 4

The density of water is greatest at

Accepted Answer

The density of water increases as temperature decreases until it reaches 4°C, after which it begins to decrease. Therefore, the greatest density of water occurs at 4°C.

Question 5

Water takes longer than air to warm up or cool off because of water's high

Accepted Answer

Water has a high specific heat which means that it can absorb and hold more heat energy than air for a given change in temperature. Similarly, it can also release heat energy more slowly than air when cooling down. This is why it takes longer for water to warm up or cool off compared to air.

Question 6

The primary sources of oxygen in a water body are the atmosphere and

Accepted Answer

Oxygen in water bodies primarily comes from the process of photosynthesis carried out by aquatic plants and algae. These organisms absorb carbon dioxide and release oxygen during photosynthesis, which can then dissolve in water. Other sources such as the atmosphere and decomposition do contribute to the level of oxygen in water, but to a lesser extent compared to photosynthesis. Evaporation does not have any direct contribution to the level of oxygen in water.

Question 7

About 75% of the Earth's surface is covered by

Accepted Answer

According to the United States Geological Survey (USGS), approximately 71% of the Earth's surface is covered by water, which includes oceans, seas, lakes, and rivers. Additionally, another 3% is covered by ice caps and glaciers, leaving only about 26% of the Earth's surface as bare ground, forest, grassland, and other types of land cover.

Question 8

The individual atoms of a water molecule are held together by

Accepted Answer

A water molecule is comprised of two hydrogen atoms and one oxygen atom, and these atoms are held together by covalent bonds. In a covalent bond, two atoms share electrons in order to fill their outer valence shells and become more stable. This sharing of electrons creates a strong bond between the atoms. Ionic bonds involve the transfer of electrons between atoms, and hydrogen bonds involve an attraction between a partially positive hydrogen atom and a partially negative atom in a different molecule. While water molecules do participate in hydrogen bonding with one another, the individual atoms within a water molecule are held together by covalent bonds. Weak bonds, such as van der Waals forces, can also exist between molecules, but they are not responsible for holding a water molecule together.

Question 9

The evaporation of water from internal surfaces of leaves,stems,and other living parts of a plant is called

Accepted Answer

The evaporation of water from internal surfaces of leaves, stems, and other living parts of a plant is known as transpiration. Option A, osmosis, refers to the movement of water from an area of low salt or solute concentration to an area of high salt or solute concentration through a semi-permeable membrane. Option C, diffusion, refers to the net movement of molecules from an area of high concentration to an area of low concentration. Option D, infiltration, refers to the process of water moving from the surface into the soil.

Question 10

Molecules spontaneously move from an area of higher concentration to an area of lower concentration in a process known as

Accepted Answer

Diffusion is the process of the movement of molecules from a higher concentration to a lower concentration without the intervention of any external forces. This process continues until the concentration of the molecules is equal throughout the space. Conduction refers to the transfer of heat or electricity from one point to another within a substance, solution involves the dissolving of a solute in a solvent, and evaporation is the process of liquid turning into a gas.

Question 11

Most of Earth's water resides in

Accepted Answer

Oceans contain approximately 97% of Earth's water.

Question 12

As light enters water,the last wavelengths absorbed are

Accepted Answer

Blue wavelengths are the last to be absorbed by water, which is why water appears blue in color when viewed in large quantities, like oceans or lakes.

Question 13

The depth of a thermocline is directly influenced by all the following factors,except

Accepted Answer

The answer of The depth of a thermocline is directly...

Question 14

The upper layer of warm,less dense water is referred to as the

Accepted Answer

The epilimnion is the upper layer of warm, less dense water in a lake or pond, typically characterized by high levels of dissolved oxygen and the presence of phytoplankton. This layer is separated from the colder, denser hypolimnion by the thermocline, a zone of rapid temperature change. The benthic zone refers to the bottom of the lake or pond, where sediment and organisms reside.

Question 15

Concentrations of solutes are greatest in

Accepted Answer

Oceans have the highest concentration of solutes among the given options due to the continuous inflow of minerals from the land and the presence of various salts dissolved in seawater.

Question 16

An organism that lives in a deep marine environment may exhibit all the following physical characteristics,except

Accepted Answer

Colorful skin pigmentation is not generally important in deep marine environments since there is little to no light at those depths. Large eyes and bioluminescence are advantageous for seeing and attracting prey or mates, respectively, and a streamlined body is useful for efficient movement through the water.

Question 17

Aquatic organisms generally require less structural support (e.g.,skeletons)due to water's high

Accepted Answer

Water's high buoyancy helps to support the weight of aquatic organisms, therefore requiring less structural support such as skeletons.

Question 18

In comparison with the epilimnion of a lake,the water of the hypolimnion is

Accepted Answer

The hypolimnion is the bottom layer of water in a stratified lake and is usually cooler than the epilimnion, the top layer of water.

Question 19

The energy driving the global water cycle is provided by

Accepted Answer

Solar energy is the primary source of energy driving the global water cycle. Energy from the sun heats the Earth's surface, causing water to evaporate and enter the atmosphere. This water vapor then condenses to form clouds, which can eventually lead to precipitation. Without solar energy, the global water cycle would not function.

Question 20

The streamlined body shape of many aquatic organisms that swim helps reduce frictional resistance caused by water's high

Accepted Answer

The streamlined body shape helps reduce frictional resistance caused by water's high viscosity, not buoyancy, surface tension, or density.

Quiz 3: The Aquatic Environment