PCB 3043 Chapter 2 || 100% Valid Answers.
Which occurs as water cools below 4C?
-The viscosity decreases.
-It becomes less polar.
-It decreases in density.
-Solutes begin to precipitate. correct answers It decreases in density.
How does the viscosity of water affect movement in small aquatic animals?
-It prevents them from sinking.
-It prevents changes in the direction of movement.
-It allows them to swim quickly.
-It allows them to swim against the currents. correct answers It prevents them from sinking.
Which water system would you expect to have the lowest dissolved-nutrient content?
-a lake
-a rain-fed stream
-an ocean
-a large river correct answers a rain-fed stream
The standard deviation of a sample is
-a measure of how close data are to a normal distribution.
-a way to determine whether the data have been measured correctly.
-an alternative measurement of the median.
-a measure of how widely the data are spread. correct answers a measure of how widely the data
are spread.
Without adaptations to control the movement of water and salts across their external surfaces,
what would happen to marine animals?
-They would be unable to maintain a sufficient nutrient concentration.
-They would be unable to maintain a boundary layer.
They would require more energy for respiration.
-They would accumulate too much salt in their cells. correct answers They would accumulate too
much salt in their cells.
What is the effect of a boundary layer in a photosynthetic organism?
-It makes it easier to diffuse carbon dioxide.
-It increases the effectiveness of sunlight collection.
-It allows the use of saltwater for photosynthesis.
-It slows the rate of gas diffusion. correct answers It slows the rate of gas diffusion.
, Why are deep ocean waters typically low in oxygen?
-slower diffusion of oxygen
-a lack of photosynthetic organisms
-the increased number of microorganisms
-reduced saturation point due to lower temperatures correct answers a lack of photosynthetic
organisms
Why are thermophilic bacteria able to withstand very high temperatures?
-high glycerol concentrations that protect cell membranes
-high proportions of particular amino acids that form strong bonds
-low concentrations of enzymes that change form at high temperatures
-cell membranes that reduce heat transfer correct answers high proportions of particular amino
acids that form strong bonds
Which is an adaptation that enables fish to survive in very cold seawater?
-increased trimethylamine oxide concentrations
-decreased urea concentrations
-increased glycerol concentrations
-decreased bicarbonate concentrations correct answers increased glycerol concentrations
Which helps organisms survive a wide range of temperatures?
-hyperosmotic molecules
-countercurrent circulation
-isozymes
-supercooling correct answers isozymes
Water has a high specific heat and thus
-only changes temperature seasonally.
-changes temperature slowly.
-never changes temperature.
-changes temperature rapidly. correct answers changes temperature slowly.
For some fish species, their swim bladder adjusts the density of their bodies to be ____ that of
the surrounding water, which facilitates energy efficient movement through the water.
-A fish's swim bladder cannot change the density of a fish's body.
-equal to
-greater than
-less than correct answers equal to
Which occurs as water cools below 4C?
-The viscosity decreases.
-It becomes less polar.
-It decreases in density.
-Solutes begin to precipitate. correct answers It decreases in density.
How does the viscosity of water affect movement in small aquatic animals?
-It prevents them from sinking.
-It prevents changes in the direction of movement.
-It allows them to swim quickly.
-It allows them to swim against the currents. correct answers It prevents them from sinking.
Which water system would you expect to have the lowest dissolved-nutrient content?
-a lake
-a rain-fed stream
-an ocean
-a large river correct answers a rain-fed stream
The standard deviation of a sample is
-a measure of how close data are to a normal distribution.
-a way to determine whether the data have been measured correctly.
-an alternative measurement of the median.
-a measure of how widely the data are spread. correct answers a measure of how widely the data
are spread.
Without adaptations to control the movement of water and salts across their external surfaces,
what would happen to marine animals?
-They would be unable to maintain a sufficient nutrient concentration.
-They would be unable to maintain a boundary layer.
They would require more energy for respiration.
-They would accumulate too much salt in their cells. correct answers They would accumulate too
much salt in their cells.
What is the effect of a boundary layer in a photosynthetic organism?
-It makes it easier to diffuse carbon dioxide.
-It increases the effectiveness of sunlight collection.
-It allows the use of saltwater for photosynthesis.
-It slows the rate of gas diffusion. correct answers It slows the rate of gas diffusion.
, Why are deep ocean waters typically low in oxygen?
-slower diffusion of oxygen
-a lack of photosynthetic organisms
-the increased number of microorganisms
-reduced saturation point due to lower temperatures correct answers a lack of photosynthetic
organisms
Why are thermophilic bacteria able to withstand very high temperatures?
-high glycerol concentrations that protect cell membranes
-high proportions of particular amino acids that form strong bonds
-low concentrations of enzymes that change form at high temperatures
-cell membranes that reduce heat transfer correct answers high proportions of particular amino
acids that form strong bonds
Which is an adaptation that enables fish to survive in very cold seawater?
-increased trimethylamine oxide concentrations
-decreased urea concentrations
-increased glycerol concentrations
-decreased bicarbonate concentrations correct answers increased glycerol concentrations
Which helps organisms survive a wide range of temperatures?
-hyperosmotic molecules
-countercurrent circulation
-isozymes
-supercooling correct answers isozymes
Water has a high specific heat and thus
-only changes temperature seasonally.
-changes temperature slowly.
-never changes temperature.
-changes temperature rapidly. correct answers changes temperature slowly.
For some fish species, their swim bladder adjusts the density of their bodies to be ____ that of
the surrounding water, which facilitates energy efficient movement through the water.
-A fish's swim bladder cannot change the density of a fish's body.
-equal to
-greater than
-less than correct answers equal to
