1. As water cools below 4°C, it expands and becomes less dense. Why is this bene
ID: 148030 • Letter: 1
Question
1. As water cools below 4°C, it expands and becomes less dense. Why is this beneficial to organisms living in a lake during a cold winter?
2. Given that heat readily transfers between an organism’s body and water, what would you predict about the temperature of the boundary layer around an animal’s body compared to the temperature of the surrounding water in cold weather?
3. Based on the properties of water, why do non-polar compounds such as fats and oils not dissolve well in water?
4. In lakes around the world, some have thick deposits of limestone, which is made up of calcium carbonate, and are resistant to the effects of acid rain. What parallels can you draw between these lakes and the smokestack scrubbers being used in coal-powered factories?
5. Both saltwater and freshwater fish have adaptations to control the movement of water and salts across their external surfaces. Describe what would happen without these adaptations.
6. How would the process of natural selection favor the evolution of increased salt tolerance during the decades that cold regions of the world have increased the use of road salt, which ultimately finds its way into streams and lakes?
7. Using your knowledge of how CO2 dissolves and reacts in water, explain why global increases in atmospheric CO2 should cause a decrease in the pH of ocean water.
8. How would counter-current selection in fish gills be beneficial for an animal trying to get rid of CO2?
9. How might the use of isozymes permit an aquatic organism to persist with a gradual increase in thermal pollution but not a rapid increase in thermal pollution?
10. If the algae that live in corals need CO2 as a carbon source for photosynthesis, why do scientists argue that global increases in CO2 are playing a role in the decline in coral reefs around the world?
Explanation / Answer
1)As water cools below 4°C, it expands and becomes less dense. It is beneficial to organisms living in a lake during a cold winter because ice becomes less dense than liquid water so it starts floating as the water becomes dense. This allows lakes to freeze only at the surface and not inside the water which allows the organisms to eaisly survive.
2) T he temperature of the boundary layer around an animal’s body will be more compared to the temperature of the surrounding water in cold weather because the metabolism rate of the animal increases inside the water which makes the body warm in water. The temperature near the body will be more while that of water will always be less
3)Non-polar compounds such as fats and oils not dissolve well in water because their ends are not charged. This means that fats are nonpolar while on the other hand water is polar, As a result the non polar molecures and water molecules do not bond and they do not share any electrons in any way. As a result , they end up floating in the water rather than blending into it.
4)TThe parallels we can draw between these lakes and the smokestack scrubbers being used in coal-powered factories is that the smokestack scrubbers will not be affected by the acid rain as they contain calcium carbonate which is resistant to the acid rain. This ensures the coal does not have any affects caused by acid rain as the calcium carbonate present in the coal counters the acid rain.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.