Biology Vocab: A1

Buoyancy

the tendency of an object to float in a fluid

• Buoyancy allows living organisms to exert less energy by floating on the surface of water

Viscosity

Thermal conductivity

Specific heat capacity

Physical and behavioral adaptations of a ringed seal

• Low-density blubber to increase buoyancy

• Streamlined, torpedo-like shape to reduce drag against viscosity

• Large, powerful flippers to exert force against viscous water

• Insulating blubber to reduce heat loss

• Seal pups survive in lairs insulated by warm, trapped air

Physical and behavioral adaptations of a black-throated loon

• large wings to generate lift in less buoyant air

• hydrodynamic shape to reduce drag against viscosity

• aerodynamic shape to reduce drag and maximize lift in less buoyant air

  • Holding wings out increases lift, wings held in reduces drag

• Hydrophobic, oil feathers to prevent penetration of water and maintain body heat

• Insulated air trapped in down feathers

Hydrogen bonds are formed by…

partially negative oxygen atoms in one hydrogen molecule being attracted to the partially positive charge of the hydrogen atom in another molecule, forming and intermolecular force.

Which atom in hydrogen has a greater attractive force?

Oxygen is more electronegative than hydrogen.

- Therefore, overall, the oxygen atom attracts the shared electrons more strongly than does the hydrogen atom

Metabolism

the sum of a cell’s chemical reactions, which must take place in liquid water.

capillary action

a phenomenon where the ascension of liquids through a tube or cylinder takes place.

In plants:
- Plants also use capillary action to move water into cell walls
- Cellulose fibers of the cell wall pull water into the spaces between them
- Adhesive forces cause water to bond to a surface AND cohesive forces hold the molecules together against the force of gravity
- As each water molecule evaporates, its hydrogen bonds pull additional water up the xylem forming continuous columns of water