Question: Instructions: 5 pages. Answer for 1-2 pages of text for each answer
1) Answer for 1-2 pages of text for each answer
2) Spell check and use good grammar. Write in full sentences with verbs and nouns.
3) TYPE each answer and put NO MORE than 2 answers on one piece of paper.
4) Answer ONLY FOUR out of the SEVEN questions.
Each Question has two or three parts. Make sure answer all parts
5) List your sources on a separate piece of paper at the end of the test (sources are journal articles, peer-reviewed scientific documents)
QUESTIONS: (remember please answer only 4!)
3) METABOLISM
A) Why are large male iguanas capable of diving for food while smaller juvenile iguanas are not? How does this affect the feeding patterns of the smaller iguanas versus the larger ones?
B) Are there terrestrial mammals larger than a blue whale? Why or why not?
4) DEEP – SEA BIOLOGY
A) Bioluminescence is an unusual physiological trait. You are either emitting light or you are not. How did evolution cross the gap? In your explanation include a description of how animals use chemistry to make light?
B) List and describe three major functions of bioluminescence. About 50% of all jellyfish are bioluminescent. What do they mostly use bioluminescence for?
5) MARINE CONSERVATION AND DIVERSITY
A) What and where are Ocean Garbage Patches?
B) Explain in detail what kinds of garbage make up ocean garbage patches.
C) Explain using one example of how ocean garbage patches might benefit marine diversity. Do you agree that this is a benefit?
6) CORAL REEFS
A) Assess the vulnerability of coral reef animals to climate-related changes in aragonite saturation states in the ocean.
B) There are only a few reefs off the northeast coast of Brazil, even though it lies in the tropics. How would you explain this?
7) SALT BALANCE & OSMOREGULATION
A) Are whales isosmotic, hyposmotic or hyperosmotic to seawater? What about humans? After drinking one liter of seawater, why are whales able to osmoregulate while humans dehydrate? Explain in detail.
B) Describe the structures common to three marine taxa that allow these animals to maintain osmotic balance. Describe for each of the three marine taxa how this (these) structure(s) helps each of the animals live in the sea.
Answer
Answers to Each Question
By: Essayicons.com
ANSWER 1: THERMOREGULATION
A) Describe the temperature classification of fish and reptiles. Why can fish, but not reptiles inhabit the cold temperate and polar oceans? What physiological factors cause the largest aquatic vertebrates to be mammals and endotherms, and the smallest teleosts to be ectotherms?
Fish and reptiles are ectothermic, meaning that they use external heat sources to regulate their body temperature. Their temperature grouping is based on their metabolism’s range preferred temperature. For instance, fish are classified into three, i.e. cold-water, cool-water, and warm-water, depending on their preferred temperature range. Cold-water fish survive in temperatures below 15 degree Celsius but not less than 10 degree Celsius. Examples include salmon and trout. Cool-water fish on the other hand thrive in temperatures ranging from 15°C- 20°C. Examples of these kinds of fish include walleye and the northern pike. Lastly, the warm-water fish prefer temperature above 20°C. Examples include bass and cat fish. Similarly, reptiles have the same classifications, with some being adapted to warmer temperatures while other thriving well in cold temperatures.
Fish can inhabit cold temperature and polar oceans because of their bodies’ ability to withstand cooler temperatures. Unlike reptiles, fish produce antifreeze proteins that counter the formation of frozen water in their cells and tissues. This adaptation allows some species such as the Arctic cod to thrive in water temperatures of below 0°C. Since reptiles do not have this adaptation, they cannot survive in very cold environments. Reptiles are adapted to warmer environments since in these environments, they are able to regulate their body temperatures by sunbathing or shading.
The largest aquatic vertebrates are mammals and endotherms (they can generate their own body heat). This enables them to maintain constant body temperatures when in cold-waters. These vertebrates also have a thick blubber layer that enables insulation which helps in heat conservation. The smallest teleosts (ectothermic fish) cannot generate their own heat and depend on external sources of heat to regulate their temperature. This inhibits them from thriving in cold waters.
B) Explain the functioning of the rete mirabile. How does this “miraculous net” help tuna function as a regional heterotherm? Describe another example where rete mirabile are used to control other environmental factors (e.g. oxygen, salinity).
The rete mirabile is a dense system comprised of arteries and veins found in some aquatic animals including tuna, sharks, and some amphibians. It is a network of veins and arteries (blood vessels). In tuna, the rete mirabile regulates their bod temperature, hence helping them to function as a regional heterotherm. A regional heterotherm refers to an animal that is adapted to maintain high temperatures in specific body parts such as muscles and some tissues while maintaining the environmental temperature in the other body parts. Due to their metabolic rate, tuna are adapted to swim at high speeds and generate a lot of body heat. However, if tuna were to generate excess heat leading to very high temperatures in their muscles, their tissues would possibly be damaged.
To avoid this catastrophe, the rete mirabile counter-flows warm blood in the arteries against cool blood in the veins. This enables the warm blood from the muscles to cool as it flows against the veins and vice versa. This adaptation helps tuna to keep their muscles’ temperature at a moderate level, while still allowing them to swim at high speeds.
Another example of rete mirabile being used to control environmental factors is in the swim bladder of some fish. A swim bladder enables fish to regulate their flexibility and maintain a stable position in the water. In some fish species such as the mackerel, the swim bladder has a rete mirabile that helps to regulate the amount of gas in the bladder. The rete mirabile enables the fish to regulate the gas volume in the bladder to sustain neutral flexibility at different depths. This functioning is essential since it prevents the fish from using a lot of energy to remain at a certain depth. It also prevents the adverse effects of pressure differences as the fish swim through different water depths. Also in some amphibians, the rete mirabile is used to extract oxygen from the air.