Bio Water Quiz

Why is water a polar molecule?

oxygen is more electronegative than hydrogen. So e

Water has a high specific heat. How is this a benefit for life on earth?

water holds on to a lot of thermal energy before raising temperature, keeping organisms + ecosystems cooler/ less prone to temperature swings

Adhesion

An attraction between molecules of different substances

Cohesion

Attraction between molecules of the same substance

How are cohesion & adhesion a benefit to life?

Because of its polarity, water is the universal solvent. What does this mean?

Can dissolve other polar substances or ionic substances

Polar molecules & Ionic compounds are hydrophilic/soluble in water. List 3 examples:

Glucose = polar, sucrose=polar, Salt + NaCl = ionic

Explain what happens to a cell when placed in a hypotonic environment?

Hypotonic environments are lower in concentration, so water will enter the cell (net movement into the cell)

Distinguish between how an animal cell and plat cell responds to a hypotonic environment.

Animal cells can lyse (burst) if exported to hypotonic environments for too long. Plant cells have a cell wall so become turgid in hypotonic environments.

The hydrogen bonding that occurs in water provides buoyancy for living things. What does this mean?

Certain organisms can float

this allows some to make habitats at the surface of water

Water readily conducts (transfers) heat which means living things like seals & loons are at risk of heat loss. How do they combat this?

Layers of non

How do animals deal with water's high viscosity?

Webbed feet. Streamlined body, other adaption of aquatic life

Where did the water on Earth come from?

Extra

What is the "Goldilocks Zone"

Earth is close enough to the sun to have thermal (heat) energy but not "too close" to be too hot. Earth's surface is not too hot or too cold for liquid water to exist.

Explain what happens to a cell when placed in a hypertonic environment?

Hypertonic environments are higher in concentration so water will exit cells (net movement out of cell).

Explain the importance of turgor pressure inside a plant. What could make turgor pressure drop?

Gives plant cells support Turgor pressure can drop if plants are exposed to hypertonic environments or not enough water (plants wilt)

Use what you know about osmosis to explain why donated human organs are stored in a solution of 0.9% NaCl. The same 0.9% solution is also used as an intravenous (IV) drip, for wounds/abrasions, and as eye drops! Why would we want to expose our cells to 0.9% salt solution rather than 0.0?

0.0% would be hypotonic to our cells, so water would enter our cells and they could potentially lyse (burst)

All living things work to maintain WATER BALANCE. When you have too much water, how does your body help you maintain homeostasis?

Filter it out = urinate more

What about when your body has too little water?

Thirst= physical indicators that you need more water