Chapter 2 Flashcards Preview

Ecology > Chapter 2 > Flashcards

Flashcards in Chapter 2 Deck (20)
Loading flashcards...
1
Q

Thermal properties of water

A

Pure water becomes a solid below 0°C and vapor above 100°C.

When water contains dissolved compounds, such as salts, its freezing temperature drops below 0°C.

Water has a high specific heat; which is the energy required to raise water temperature by 1°C.

2
Q

Density of water

A

Water is at its highest density at 4°C.

Above and below 4°C, the density of water decreases.

Ice is less dense than liquid water, so it floats on the surface. As a result, the lower layers of lakes and ponds are typically ice-free during winter.

3
Q

Adaptations to water density

A

Some body tissues are more dense than water (e.g., bone); some are less dense (e.g., fats).

Organisms have developed many adaptations to cope with their tendencies to sink or float.

4
Q

saturation

A

Every mineral has an upper limit of solubility in water, known as saturation.

Beyond saturation, minerals precipitate out of water.

5
Q

Acidity

A

the concentration of H+ ions in a solution.

Acidity is measured as pH: pH = –log(H+ concentration).

Water with low pH is acidic, medium pH is neutral, and high pH is basic or alkaline.

Acidic water can dissolve toxic metals and negatively affect enzyme activity.

6
Q

Acid rain

A

In the 1960s, many bodies of water downwind of coal-powered factories were becoming more acidic.

This was due to acid deposition, also known as acid rain; sulfur and nitrogen dioxides emitted by smokestacks were carried down to land by precipitation.

Water became toxic to many species of aquatic organisms.

On land, acid deposition caused nutrients to leach out of leaves and soils, and reduced the ability of plants to take up nutrients.

7
Q

Semipermeable membranes

A

membranes that allow only particular molecules to pass through; reduces free movement of solutes

8
Q

Osmotic potential

A

the force with which a solution attracts water by osmosis.

9
Q

Marine fish

A

hypo-osmotic (tends to gain salts and lose water)

continually drink seawater

excrete salts through gills

excretes small amounts of dilute urine

10
Q

Freshwater fish

A

hyper osmotic (tends to lose gain water and lose salts)

water enters body (does not drink water)

pees a lot but absorbs salts from urine

large amounts off urine

11
Q

Ammonia in sharks and rays

A

Sharks and rays convert ammonia, a by-product of protein digestion, into urea.

Most urea is excreted, but some is retained in the bloodstream.

This raises the osmotic potential of their blood to that of seawater, which balances water movement.

They accumulate trimethylamine oxide in blood to protect proteins from the harmful effects of urea.

12
Q

Diffusion of carbon dioxide

A

Plants need carbon dioxide (CO2) for photosynthesis.

CO2 diffuses slowly through water; plants use CO2 faster than it diffuses into leaf tissues.

CO2 is rapidly converted to bicarbonate (HCO3–) or carbonate (CO3–) ions, which accumulate in massive quantities and can be used for photosynthesis.

Even when CO2 and HCO3– are abundant, they diffuse slowly and limit plant growth.

13
Q

Boundary layer

A

a region of unstirred air or water that surrounds the surface of an object. Removed gases from this region are slow to be replaced; this further limits carbon availability.

14
Q

Oxygen gas (O2) in air is ___% by volume; in water it is ___%.

A

21% ; 1%

15
Q

Countercurrent circulation

A

is an adaptation where blood and water flow in opposite directions so that the concentration of O2 in water is always greater than the concentration in blood.

16
Q

anaerobic or anoxic

A

When an environment becomes completely devoid of oxygen

17
Q

Q10 value

A

a ratio of a physiological process rate at one temperature to the rate of that process when the temperature is 10°C cooler.

The rate of most biological processes increases 2 to 4 times for each 10°C rise in temperature.

18
Q

Glycerol and glycoproteins

A

chemicals present in some animals (e.g., Arctic cod) that prevent freezing by reducing strength of hydrogen bonds or via supercooling.

Marine vertebrates are susceptible to freezing; added solutes in seawater lower freezing point to –1.9°C, whereas the freezing point of water in animals is higher.

19
Q

Thermal optima

A

the range of temperatures in which an organism best performs.

20
Q

Isozymes

A

different forms of an enzyme that catalyze a reaction.

Having two or more isozymes suited for different temperature ranges is useful for organisms that must cope with variable temperatures