A1.1 Water (IB HL Biology)

Water.. yum

What is the medium of life?

Water is the medium of life (because of the beneficial factors it provides.)

How do water molecules bond?

Water molecules bond through hydrogen bonding (because water is a polar molecule.)

What is Adhesion? (Referred to water)

Adhesion is the sticking together of dissimilar molecules (different/other polars or charges.)

What is Cohesion? (Regarding water)

Cohesion is the sticking together of similar molecules (the same polars or charges)

Solvent Properties of Water

Water can dissolve polar/charged molecules but not nonpolar molecules (like fats), due to “like dissolves like”… (water is polar)

Physical Properties of Water

Buoyancy, viscosity, thermal conductivity, and specific heat capacity.

Buoyancy

The upward force of the liquid

Viscosity

Resistance to flow (thickness)

Thermal Conductivity

Ability of material to transfer heat

Specific Heat Capacity

Amount of energy it takes to change the temperature (of the capacity: unit of mass of a substance by one degree Celsius.)

Ringed Seal Adaptations (Regarding water)

Seal is less buoyant due to relatively dense bones (allowing it to stay submerged underwater upon diving), streamlined body to help get through water (since water has higher viscosity than air, Fur and fat that prevents heat loss while in water (low thermal conductivity), low specific heat capacity due to non-effective cooling mechanisms.

Black-Throated Loon (Regarding water)

Loon had medium buoyancy due to less dense bones (but not hollow, so it can drive underwater), Higher viscosity against water due to their legs, Thermal conductivity from feathers (the oil clashes against the water; making the water unable to wet the feathers, and creating a barrier that prevents heat loss)—(water has a higher thermal conductivity).

Where does Water come from?

Water comes from asteroids, as the frozen water located on them melts and becomes a liquid upon hitting earth (the water stays on earth.)

Where do we look for aliens and why?

We look for aliens at the Goldilocks zone, as the area is where water is able to take liquid form (and as we know, water as a liquid provides hydration, crucial for living.)