Molles Water Relations Exam Questions Chapter 6

Ecology, 8e (Molles)

Chapter 6 Water Relations

1) The water availability for organisms is determined by

A) internal dissolved ion concentrations.

B) external dissolved ion concentrations.

C) movement of water down its concentration gradient.

D) movement of water up its concentration gradient.

E) None of the choices are correct.

2) Saturation water vapor pressure

A) increases with temperature.

B) decreases with temperature.

C) parallels vapor pressure density.

D) both increases with temperature and parallels vapor pressure density.

E) both decreases with temperature and parallels vapor pressure density.

3) Movement of water ________ its concentration gradient is called ________.

A) down; diffusion

B) up; diffusion

C) down; active transport

D) up; osmosis

E) None of the choices are correct.

4) Aquatic organisms whose body fluids equal that of their surroundings are

A) hyperosmotic.

B) isosmotic

C) hypoosmotic.

D) osmotic.

E) None of the choices are correct.

5) Aquatic organisms whose ionic concentration of their body fluids exceeds that of their surroundings are

A) hyperosmotic.

B) hypoosmotic.

C) isoosmotic.

D) osmotic.

E) None of the choices are correct.

6) Aquatic organisms whose ionic concentration of their body fluids is less than that of their surroundings are

A) hyperosmotic.

B) isoosmotic.

C) hypoosmotic.

D) osmotic.

E) None of the choices are correct.

7) If a person were to place a marine fish into a fresh water lake, water would diffuse

A) up its concentration gradient and enter the fish.

B) down its concentration gradient and enter the fish.

C) down its concentration gradient and exit the fish.

D) up its concentration gradient and exit the fish.

E) None of the choices are correct.

8) The potential for evaporative water loss by terrestrial organisms

A) decreases with increased vapor pressure deficit.

B) increases with decreased vapor pressure deficit.

C) increases with increased vapor pressure deficit.

D) None of the choices are correct.

9) In a terrestrial plant, water movement is as follows:

A) from less negative water potential to a more negative water potential.

B) from more negative water potential to a less negative water potential.

C) from less positive water potential to a more positive water potential.

D) from zero water potential to a more negative water potential.

E) from zero water potential to a more positive water potential.

10) All of the following contribute to the movement of water in a terrestrial plant except

A) transpiration.

B) drying power of the sun.

C) hydrogen bonding.

D) water potential.

E) None of the choices are correct.

11) In general, a plant located in an arid climate will possess all of the following in order to prevent water loss except

A) waxy coating.

B) decreased root biomass.

C) decreased shoot biomass.

D) increased root length.

E) reduces leaf size.

12) In order to survive in the desert, a camel will employ which of the following mechanisms?

A) Face away from sun

B) Store water in its hump

C) Shed its fur

D) Allow its body temperature to rise

E) All of the choices are correct.

13) A desert scorpion will use all of the following mechanisms in order to survive in the desert except

A) waterproof cuticle.

B) nocturnal behavior.

C) burrowing.

D) decreased metabolic rate.

E) None of the choices are correct.

14) In general, desert organisms try to decrease their rate of evaporative cooling in order to conserve water. Which of the following desert organisms sweats?

A) Camel

B) Cactus

C) Cicada

D) Scorpion

E) Tiger beetle

15) Bony marine fish

A) drink sea water.

B) secrete Na+ into the surrounding water.

C) are hyperosmotic compared to the surrounding water.

D) both drink sea water and secrete Na+ into the surrounding water.

E) drink sea water, secrete Na+ into the surrounding water, and are hyperosmotic compared to the surrounding water.

16) Water vapor is continuously added to the air by

A) transpiration.

B) evaporation.

C) both transpiration and evaporation.

D) precipitation.

E) both evaporation and precipitation.

17) The evaporative water loss by an organism is high when the

A) vapor pressure deficit is low.

B) relative humidity is high.

C) water concentration gradient from the organism to the air is reduced.

D) actual water vapor density is very low relative to the saturation water vapor density.

E) All of the choices are correct.

18) A(n) ________ marine fish gains water through osmosis and loses salts through diffusion.

A) hyperosmotic

B) hypoosmotic

C) isoosmotic

D) osmotic

E) None of the choices are correct.

19) Which of the following may be used to study the uptake of water by plants in a natural ecosystem?

A) Non-stable isotope analysis

B) Radioactive isotope analysis

C) 14C isotope analysis

D) Stable isotope analysis

E) Water isotope analysis

20) The camel and saguaro cactus both

A) acquire massive amounts of water when water is available.

B) allow their internal temperature to rise.

C) reduce surface area exposed to direct sunlight.

D) reflect sunlight with dense hairs.

E) All of the choices are correct.

21) A cicada will use which of the following mechanisms in order to survive hot, dry conditions of the desert?

A) Nocturnal behavior

B) Burrowing

C) Torpor

D) Sweating

E) All of the choices are correct.

22) Water conservation mechanisms used by plants adapted to dry conditions include

A) dropping leaves.

B) thick leaves.

C) fewer stomata.

D) dormancy.

E) All of the choices are correct.

23) The Namib Desert beetle, Onymacris unguicularis, obtains its water through positional maneuvers during foggy weather conditions.

24) Desert kangaroo rats meet a portion of their water requirements through the metabolic processing of their food intake, but they still need to drink liquid water in order to survive.

25) Windy days will decrease a plant's evaporative water loss.

26) Most water loss in terrestrial animals is due to evaporation.

27) In general, a plant found growing in the desert can be expected to have a low shoot to high root biomass ratio.

28) In order to reduce heat gain, a camel will face into the sun.

29) Freshwater fish and freshwater mosquitoes must actively excrete ions such as Na+ and Cl-.

30) Sharks, rays, and skates retain urea and trimethylamine oxide (TMAO) within their blood allowing them to become only slightly hyperosmotic thereby reducing the cost of osmoregulation.

31) A high water vapor pressure deficit indicates that the water vapor content of the air is near saturation.

32) Water flows from the soil into the plant roots because the water potential of the soil is higher than the water potential of the roots.

33) Relative humidity = [ ________ / saturation water vapor density] x 100

34) The diffusion of water across a differentially permeable membrane is called ________.

35) Metabolic water is the water that is released by the process of ________.

36) D:1H ratios in plants can be used to evaluate relative use of summer and winter rainfalls because summer rains are ________ in D and winter rains are ________ in D.

37) The Sonoran desert cicada emits its buzzing call only when temperatures are below 10 ºC, when all other animals have taken refuge from the cold.