2. Identify and describe four various chemical factors that affect marine life. Salinity, density, temperature, pH Describe one marine adaptation for each of the factors (in previous question) that helps organisms survive in a complex and hostile environment. Osmoconformation, lack of an internal skeleton, blubber, photosynthesis Compare and contrast cohesion and adhesion. Cohesion and adhesion are water’s stickiness to other things. Cohesion is water sticking to other water, adhesion is water sticking to non-water molecules. Identify the five properties unique to water. Liquid at room temperature, ice floats, its sticky, viscous, has surface tension Unit 2 Review

3. Explain how the unique chemistry of water causes ice to float. Similarly charged H & O atoms don’t want to be near to each other. As temperature decreases, density increases, to a point. At max. density, Hs and Os push apart, decreasing density  ice floats! Explain the concept of hydrogen bonding and three effects it has on the chemistry of water and real life examples. Water is a polar molecule with ends that are oppositely charged. These charges allow adjacent water molecules to stick to each other. This causes water to have a high heat capacity, surface tension, and ice floats. Unit 2 Review

4.  Explain how and why water is critical to the climate of Earth and its inhabitants.  Water absorbs heat much more than soil; as a result coastal regions are cooler than regions inland.  Identify two substances (such as salt and carbon) and describe how they move through Earth’s systems.  Carbon is added into the marine system by weathering and decomposition and is taken up in the food chain as organisms eat each other.  Phosphorous is also added through weathering and decay and removed by consumption. Unit 2 Review

5. Choose two key organic chemicals (C, N, O, P, Si, and others) and explain their importance. Carbon is the backbone of nearly all molecules in living organisms. Phosphorous and nitrogen are key to building DNA Compare and contrast diffusion and osmosis. Diffusion is movement of molecules from high to low concentration, osmosis is movement of WATER from high to low concentration. Both are forms of passive transport. Compare and contrast osmoregulators and osmoconformers. Describe the effect of temperature on water density and dissolved oxygen. As temperature decreases, density and level of DO increase.

6. Identify and describe four physical factors that affect marine life. Temp, light, pressure, acoustics (movement of sound through water) Describe one marine adaptation for each of the factors (in previous question) that helps organisms survive in a complex and hostile environment. Blubber, chloroplasts (photosynthesis) in algae, swim bladder/compressible lungs, echolocation Describe the effect of salinity on water density. More salt increases density Describe the effect of water depth on temperature, pressure and the absorbance of visible light. As depth increases, temperature and visible light decreases but pressure increases. Unit 2 Review

7. Explain how visible light interacts with water and is absorbed by water. Wavelengths of light (ROYGBV) are absorbed as they penetrate water. Red is absorbed out first because it contains the least amount of energy, and blue light is absorbed out last. Compare and contrast the photic and aphotic zones. Photic zone contains the greatest amount of light and permits photosynthesis and aphotic zone lacks light. In both zones, light is absorbed. Describe the adaptations that help organisms overcome the drag force of water; in other words, become more hydrodynamic. Streamlined body shape, mucous to make them slippery, moving slow so viscosity isn’t a factor Explain the hazards of high pressures on living organisms (associated with diving to great depths) and the various adaptations used to limit or overcome these hazards. Skip this one Unit 2 Review

8. Describe the adaptations that allow organisms to overcome these challenges: Viscous water: streamlined body Cold temperature: extensive capillary beds in circulatory system to exchange heat throughout body Salinity: osmoregulation Lack of light: bioluminescence Pressure: invertebrate body plan: pressure inside and outside body are equal. Unit 2 Review