Adaptations to Aquatic Environments

Flashcards covering key ecological and physiological concepts regarding aquatic environment adaptations, including physical properties of water, osmoregulation, gas diffusion, and thermal optima.

What is the specific heat of water?

It requires $1\,\text{Calorie}$ of energy to raise $1\,g$ of liquid water by $1\,^\circ\text{C}$.

At what temperature does pure water reach its highest density?

Pure water reaches its highest density at $4\,^\circ\text{C}$.

Which specific micronutrient is required by diatoms to form their outer shells?

Silica.

What term describes the upper limit of solubility of a mineral in water?

Saturation.

How is acidity measured on the pH scale?

$$\text{pH} = -\log([H^+])$$

What chemical equation represents the weathering of limestone by acidity?

$$H^+ + CaCO_3 \rightarrow Ca^{2+} + HCO_3^-$$

How do algae adapt to maintain buoyancy in water?

They use droplets of oil as floatation devices.

How does temperature affect the viscosity of water?

Cooler water is more viscous than warm water.

What rule governs the net direction of water movement during osmosis?

Water moves towards the higher concentration of dissolved solutes.

How do freshwater fish maintain their water and solute balance?

They gain water osmotically through gills and mouth, eliminate excess water with urine via kidneys, actively take up solutes through gills, and retain most solutes in urine.

How do sharks and rays maintain an isosmotic balance with ocean water?

They convert metabolic waste into urea and retain it in their blood to increase solute concentration to match the ocean's osmolarity.

How does the concentration of oxygen in air compare to its concentration in water?

The concentration of oxygen in air is $21$ times greater than in water ($[O_2]_{\text{air}} = 21 \times [O_2]_{\text{water}}$).

How does countercurrent flow in fish gills maximize oxygen uptake?

Blood and water flow in opposite directions across gill lamellae, maintaining a continuous gradient where oxygen concentration in water is always greater than in blood.

What is a boundary layer on an aquatic plant leaf, and how does it impact gas exchange?

It is a region of unstirred air or water surrounding the surface of an object that slows down the delivery of gases like $CO_2$ to the leaf.

What compounds do aquatic organisms produce to prevent cell damage from freezing?

Glycerol and glycoproteins, which lower freezing points by supercooling or reducing hydrogen bond strength.

What are isozymes, and how do rainbow trout use them to adapt to temperature changes?

Isozymes are different structural forms of an enzyme optimized for different thermal conditions; rainbow trout produce winter and summer forms to maintain enzyme-substrate affinity across seasons.

What primary physiological process occurs during coral bleaching?

Abnormally warm temperatures cause coral hosts to expel their symbiotic photosynthetic algae.

In the metabolic theory of ecology, what is the $Q_{10}$ value?

It is a ratio measuring a physiological process rate at one temperature compared to the rate of that process at a temperature $10\,^\circ\text{C}$ cooler.