Chapter 2: Adaptations to Aquatic Environments Flashcards
(94 cards)
What gives water its important characteristics?
Its polarity
What property of water allows for the hydrologic cycle?
Its ability to exist in all three phases of matter on Earth
Why is the fact that ice floats important to biological life?
If water reached its higest density as ice, in shallow freshwater environments in temperate and subartic climates, ice freezing at the surface would sink an dthe water body would be more likely to freeze solid, killing species contained therein
When is water most dense?
At 4 degrees Celsius
What does water become a solid?
0 degrees Celsius
What happens to the freezing temperature of water when compounds are dissolved within it?
The temperature drops to below 0 degrees Celsius
What happens to the boiling point of water when substances are dissolved within it?
The boiling point increases above 100 degrees Celsius
Water remains liquid over a broad range of temperatures because of its _____________________, which is the amount of heat required to increase water’s temperature by 1 degree Celsius
High specific heat
As water cools to 4 degrees Celsius, its _____________ stays the same but its __________ decreases, resulting in its most dense form
Mass
Volume
When water freezes at 0 degrees Celsius, its _________ stays the same, but its __________ increases, making it less dense
Mass
Increases or expands
What two things determine whether an organisms will sink or float in water?
- Body composition
- Presence of air pockets
What are three adaptations organisms have developed to reduce density and retard sinking?
- Many fish have air-filled bladders
- Some kelps have air-filled bulbs
- Whales release air slowly
Why do some microscopic unicellular algae float in great numbers?
They use oil as flotation devices because oils are less dense than water
What diatomic organism produces an oil droplet to help it float?
Cyclotella cryptica
__________________ refers to the thickness of a fluid that causes objects to encounter resistance as they move through water
Viscosity
What two adaptations were discussed in class to combat the high viscosity of water?
- Large animals developed streamlined shapes
- Small animals developed long, filamentous appendanges
Large animals, like fish, penguins, and whales, have evolved highly streamlined shapes that reduce _______________ caused by the high viscocsity of water
Drag
Many tiny marine animals have evolved long, filamentous appendances that cause greater _____________ in water, functioning like a parachut, slowly the fall of the body through water
Drag
What contributes to the ability of small snimals from sinkin?
Increased surface area
________________ are partial intermolecular bonding interactions between a lone pair on an electron rich donor atom, particularly the second-row elements nitrogen, oxygen, or fluorine, and the antibonding molecular orbital of a bond between hydrogen and a more electronegative atom or group
Hydrogen bonds
___________________ is a type of chemical bond where a pair of electrons is unequally shared between two atoms. In a polar covalent bond, the electrons are not equally shared because one atom spends more time with the electrons than the other atom
Polar covalent bonding
_____________________ measures the tendency of an atom to attract a shared pair of electrons (or electron density)
Electronegativity
_______________ refers to the tendency of water molecules to be attracted, or ‘‘stick’’, to other substances. This is a result of the covalent bond between the two hydrogen atoms and the one oxygen atom in the water molecule
Adhesion
__________________ refers to the attraction of molecules for other molecules of the same kind, and water molecules have strong cohesive forces thanks to their ability to form hydrogen bonds with one another
Cohesion
