Monday, December 3, 2007

Chapter 6 Critical Thinking

2.) Only very few flowering plants have invaded the oceans, but those that have are very successful. What are some possible reasons for the small number of marine flowering plants? How do those that have taken the step manage to thrive in some environments?
-An example is the Seagrass flowers, whose closest relatives seem to be members of the lily family, which shows that seagrasses evolved from land plants. But they have very well adapted to life in the marine environment. Instead of attracting insect for pollination, the pollen is carried by the water currents. Tiny seeds result from successful fertilization. These seeds are dispersed by water currents and perhaps in the feces of the fish and other animals that browse on the plants.

Chapter 5 Critical Thinking

1.) Scientists use the particular structure of nucleic acids and other chemical differences to separate the archaea from the bacteria. Can you think of other characteristics that could be used to distinguish not only between these two domains but also between them and Protists?
Ancestral Organism
a. Archae
b. Bacteria
a. Fungi
b. plants
c. animals
The two prokaryotic domains, Bacteria and Archaea, have important differences, including the chemistry of their cell walls and plasma membranes, and the cellular machinery that manufactures proteins. They are the simpliest and most primitive form of life that we know. Protists are mostly aquatic primary producers that lack the specialized tissues of plants. They range in size and compllexity from single cells to large multicellular seaweeds.

Chapter 14 Critical Thinking

1)What factors might account for the fact that the vast majority of atolls occur in the INdian and Pacific oceans and that atolls are rare in the Atlantic?
-Atolls are strongly influenced by these winds called the trade winds blow from latitudes of about 30 degrees toward the equator. And there are more warm surface currents in the Indian and Pacific Ocean than in the Atlantic Ocean.

3)There are only a few reefs off the northeast coast of Brazil, even though it lies in the tropics. How would you explain this?
- It is common for reef building corals also because rivers bring in a lot of silty sediment, which is generally unfavorable to corals.

2) Scientist predict that the ocean will get warmer and the sea level will rise as a result of an intensified greenhouse effect. How might this affect coral reefs?
- Because of global warming the earth is getting warmer. This change will affect the already stressed ecosystems such as mangrove forests and estuaries will be flooded; coral reefs may not grow fast enough to keep up with the rising sea levels.

Sunday, November 18, 2007

Chapter 9 Critical Thinking

Sea turtles have disappeared from many regions, and one way of trying to save them is to reintroduce them to areas where they have been wiped out. This is done by reburying eggs or by releasing newborn baby turtles on beaches. Why are eggs reburied or baby turtles released instead of fully grown individuals?

Maybe because new born and/or eggs would be more effective to reproduce again...the old turtles may be more relaxed and unable to reproduce. The only thing about reburying eggs is that other species may eat the egg which leads to no baby turtles.

Chapter 1 Critical thinking

2.) In Chapter 1 it was expalined that the statement "There are mermaids in the ocean" is not a valid scientific hypothesis. Can the same be said of the statment "There are no mermaids in the ocean"? Why?

-->The statement, "There are no mermaids in the ocean", is not a valid scientific hypothesis, because it is not testable. This statement cannot be potentially proven to be false. Even if an army of marine biologists were to spend their entire career looking for a mermaid, the ocean is far too large for such a study. There may be some comments on individuals seeing a mermaid...then again people say things to noticed or known...proof would be the first step to proving the statement, "There are no mermaids in the ocean" or "there are mermaids in the ocean". As for now no hard core evidence to prove both these statements.

Chapter 3 Critcal Thinking

4.) Most tsunamis occur in the Pacific Ocean, as indicated by the map in the "Waves that Kill" boxed reading. How would you explain this?-->Tsunamis are caused from earthquakes, landslides, volcanoes, and other seismic disturbances of the sea floor. Unfortunately, 85% of all tsunamis occured in the Pacific Ocean. Around the rim of the Pacific Ocean are many volcanoes. This is known as the Pacific Rim of Fire. These eruptions are one of the main causes of the seismic activity in the Pacific Ocean.