Chapter 8 Critical Thinking
1.) Hagfishes and lampreys are the only living representatives of a very ancient group. Why do you suppose there are still some of these jawless fishes around?
--> Jawless fishes are know to be the most primitive fishes living today. I suppose they have exsited this long due to their feeding habits. They feed mostly on dead or dying fishes. This resource is simply impossible to run out off.
2.) A deep-water shark, new to science, is collected for the first time. The specimen is studied in detail, but its stomach is empty. How could you get a rough idea of its feeding habits? The specimen is a female, and its reproductive tract is found to contain 20 eggs. Can you tell the type of developement characteristic of this species?-->
In order to determine the feeding habits of this new specimen, you can study the jaws. Not all of the nearly 350 living species of sharks conform the same body plan, but the majority are known to contain rows of numerous sharp, often triangular teeth. This feature helps since sharks are known to be adapted for predatory feeding. Also to keep in mind, that there are sharks (whale sharks) that are filter feeders. This is could very well help explain an empty stomach. Because this specimen is yet to be unknown, it is hard to study the type of developement characteristic of the 20 eggs found. There are two different types of sharks that may very well affect the developement. One is oviparous and the other is viviparous. In an oviparous shark, the yolk is needed to provide energy for at least several months of development. Without this amount of time, the eggs won't be fully developed. And in a vivparous shark, nutrition is provided by direct contact with the reproductive tract of the female.
3.) Individuals of some species of bony fishes change sex, some to maintain more males than females, others more females than males. What are the advantages and disadvantages of each situation? Are there any advantages and disadvantages in having an equal number of males and females?
-->One advantage of maintaining more males than females is that there will be more chances of having a dominant male. Since a dominant male is needed to triger these changes (protandry and protogyny). A disadvantage of this situation will be that with less female, there will be less chances of reproduction. Whereas, this would be an advantage of having more females than males. And as for having an equal number of males and females, I think that there will be no advantages or disadvantages, since everything will turn out to be average.
Sunday, November 18, 2007
Sea Floor Spreading
What is sea floor spreading?
-->Sea-floor spreading is the process in which the ocean floor is extended when two plates move apart. As the plates move apart, the rocks break and form a crack between the plates. Earthquakes occur along the plate boundary. Magma rises through the cracks and seeps out onto the ocean floor like a long, thin, undersea volcano. library.thinkquest.org/17457/platetectonics/4.php
What are some of the major land forms that are created from plate movement?
-->A long chain of mountains forms gradually on the ocean floor as magma piles up along the crack. This chain is called an oceanic ridge. library.thinkquest.org/17457/platetectonics/4.php
How were the Mariana Islands formed?
-->A theory known as plate tectonics presumes that the Asian continent and the North and South American continents are moving and that the Lithosphere (crust) of the continents are composed of different material. The edge of these plates are believed to be moving in such a manner that one moves under the other and the cataclysmic forces that result push material upward to form islands. www.cnmi-guide.com/history/formation
What evidence exists today that the plates are still moving and that the islands are ancient volcanoes?
-->Plate tectonics is a theory of geology that has been developed to explain the observed evidence for large scale motions of the Earth's lithosphere. That facts that the fitting together of the coasts of the continents on the opposite sides of the Atlantic Ocean, the similarity of geologic formations and fossils found on the opposite sides, a geologically active mid-ocean ridge running along the central Atlantic between the opposite coasts, bottom sediments that get thicker the farther one travels from the ridge, and rocks on the sea floor on one side of the ridge show magnetic bands that are mirror images of rocks found on the opposite side of the ridge. en.wikipedia.org/wiki/Plate_tectonics#Plate_tectonic_theory
What is an atoll?
-->An atoll is an island of coral that encircles a lagoon partially or completely. Darwin (an English Naturalist) reasoned that a fringing coral reef surrounding a volcanic island in the tropical sea will grow upwards as the island subsides, becoming an "almost atoll" (barrier reef island). The fringing reef becomes a barrier reef for the reason that the outer part of the reef maintains itself near sea level through biotic growth, while the inner part of the reef falls behind, becoming a lagoon because conditions are less favorable for the corals and calcareous algae responsible for most reef growth. In time, subsidence carries the old volcano below the ocean surface, but the barrier reef remains. At this point, the island has become an atoll. http://en.wikipedia.org/wiki/Atoll
Why are atolls mainly found on the Pacific?
Atolls are the product of the growth of tropical marine organisms, so these islands are only found in warm tropical waters. Volcanic islands located beyond the warm water temperature requirements of reef building organisms become seamounts as they subside and are eroded away at the surface. An island that is located where the ocean water temperatures are just sufficiently warm for upward reef growth to keep pace with the rate of subsidence is said to be at the Darwin Point.http://en.wikipedia.org/wiki/Atoll
Thursday, October 11, 2007
Starfish
Lateral Canal- tube feet are attached.
Stone Canal- where water enters.
canal- leads from the ring canal to the madreporite.
abulacral groove- extends down the underside of each arm.
spines- protects starfish and are part of internal skeleton.
madreporite- this is where water enters.
central disc- center of starfish.
dorsal or aboral- top of starfish.
mouth- underside
Name of organism: Starfish - Phylum
Habitat: usually in rock places in the ocean, bottom of sea, coral reefs, or even sands.
Food source: algal films, feed on something dead, or mussels.
Life cycle: Male or female, Fertilization is external and occurs when sea stars release enormous numbers of sperm and eggs in the ocean.
Moves by: The underside of the starfish is covered with hundreds of tube feet, which it uses for walking around, for attaching tightly to rocks, and for holding on to prey. To move, each tube foot swings like a leg, lifting up and swinging forward, then planting itself on the ground and pushing back. At the tip of each tube foot is a suction cup. These aren't used when walking on level ground, but can be used when walking up sheer surfaces (How starfish move-online).
Unique Characteristics: On the underside of each sea star is the mouth along with a distinct cleft through which food is moved to the mouth. Some sea stars do not have a separate opening for removing waste and as such, their "mouths" act as both the site for the import of food and the export of waste materials. Interestingly, these invertebrates are also capable of regenerating body parts from body fragments.
Role: The starfish role in the ecosystem is just plain and simple. They are harmless and come in beautiful colors. They just tend to make the ocean more colrful and beautiful. it is an eye catcher to marine life and humans as well.
Stone Canal- where water enters.
canal- leads from the ring canal to the madreporite.
abulacral groove- extends down the underside of each arm.
spines- protects starfish and are part of internal skeleton.
madreporite- this is where water enters.
central disc- center of starfish.
dorsal or aboral- top of starfish.
mouth- underside
Name of organism: Starfish - Phylum
Habitat: usually in rock places in the ocean, bottom of sea, coral reefs, or even sands.
Food source: algal films, feed on something dead, or mussels.
Life cycle: Male or female, Fertilization is external and occurs when sea stars release enormous numbers of sperm and eggs in the ocean.
Moves by: The underside of the starfish is covered with hundreds of tube feet, which it uses for walking around, for attaching tightly to rocks, and for holding on to prey. To move, each tube foot swings like a leg, lifting up and swinging forward, then planting itself on the ground and pushing back. At the tip of each tube foot is a suction cup. These aren't used when walking on level ground, but can be used when walking up sheer surfaces (How starfish move-online).
Unique Characteristics: On the underside of each sea star is the mouth along with a distinct cleft through which food is moved to the mouth. Some sea stars do not have a separate opening for removing waste and as such, their "mouths" act as both the site for the import of food and the export of waste materials. Interestingly, these invertebrates are also capable of regenerating body parts from body fragments.
Role: The starfish role in the ecosystem is just plain and simple. They are harmless and come in beautiful colors. They just tend to make the ocean more colrful and beautiful. it is an eye catcher to marine life and humans as well.
Wednesday, October 3, 2007
DNA and RNA
DNA and RNA
1. What is DNA?
- DNA - the Blueprint of Life
Every living organism contains within itself the information it needs to build a new organism. This information, you could think of it as a blueprint of life, is stored in the organism's genome. The genome is made up of a material called DNA, which stands for deoxyribonucleic acid. If you take a really, really close look at the DNA molecule you will see that it looks like an ordinary ladder, although somewhat twisted. The steps that connects the two strands in this ladder are composed of four different molecules of the same type, called nucleotides.
2. What are the 4 bases?
- In DNA they are A, T, C and G; where A stands for adenine, T for thymine, C for cytosine and finally G for guanine.
3. What 2 peices of information did the scientists need to solve the elusive structure of DNA?
- Phosphate backbone, double helix.
4. What are the specific base pairs?
- (adenine,thynine) (guanine,cytosine)
5. How does the pairing rule effect the shape and structure of DNA?
- Each rung of the twisted ladder in the Helix would be of equal size, and the sugar-phosphate backbone would be smooth.
6. What does the DNA do during cell division?
- It is able to unzip into two pairs.
7. How many base pairs does E. Coli have? How long does it take to replicate? How is the DNA packaged in the cell?
- It makes 4 million pairs in once every 20 minutes and it is curled up in a condensed fashion.
8. How many base pairs does Human DNA have? How long does it take to replicate? How is the DNA packaged in the cell?
- It makes 3 billion pairs in about 12 - 24 hours and is packaged into 23 distinct chromosome pairs.
1. What is RNA? How different is it from DNA?
RNA - a Blueprint Copy
-When an organism needs to use the data stored in the genome, e.g. to build components of a new cell, a copy of the required DNA part is made. This copy is called RNA and is almost identical to DNA. Just like DNA, RNA is an abbreviated form of a chemical name which in the case of RNA is ribonucleic acid.
2. How are the RNA messages formed?
- The alphabet in the RNA molecule contains 4 letters, i.e. A, U, C, G as previously mentioned. To construct a word in the RNA language, three of these letters are grouped together. This three-letter word are often referred to as a triplet or a codon. An example of such a codon is ACG. The letters don't have to be of different kinds, so UUU is also a valid codon. These codons are placed after each other in the RNA molecule, to construct a message, a RNA sequence. This message will later be read by the protein producing machinery in the body. The RNA part to the left contains 39 letters and since each codon contains 3 letters, 13 codons are present (39 letters divided by 3 letters equals 13 words or codons.)
3. How are the RNA messages interpreted?
- Every organism has an almost identical system that is able to read the RNA, interpret the different codons and construct a protein with various combinations of the amino acids mentioned previously. In fact every RNA word or codon, corresponds to one single amino acid. These codons and their correlation with the amino acids in a protein sequence is what defines the genetic code.
1. Describe cell cycle.
- The cell cycle illustrates the different phases of division. The key molecules which control and coordinate cell division are called “CDK” and “Cyclin”. Chromosomes in cell nucleus Gap 1 Phase: Cell growth begins Synthesis Phase: Chromosomes divide and duplicate, Cell growth continues Gap 2 Phase: Cell reaches proper size Mitosis Phase: Cell Division.
2. What is nuclear division.
-
3. What is interphase.
- A stage in the cell cycle when a cell doubles its cytoplasm and synthesizes DNA. Interphase is the "holding" stage or the stage between two successive cell divisions.
4. Cytokinesis.
- Cytokinesis refers to the division of a eukaryotic cell. Cytokinesis usually occurs after a cell has undergone nuclear division as part of mitosis or meiosis. Except for some special cases, the amount of cytoplasm and number of organelles and cellular components in each daughter cell is redistributed equally to each daughter cell. Notable exceptions include oogenesis, where the ovum nearly takes all the cytoplasm and organelles, leaving little for the resulting polar bodies, which then die.
5. Homologous chromosomes.
- A pair of chromosomes made up of two homologs. Homologous chromosomes have corresponding DNA sequences and come from separate parents; one homolog comes from the mother and the other comes from the father. Homologous chromosomes line up and synapse during meiosis.
6. Phases of mitosis (5 of them).
- Phase 1: Interphase the chromosomes replicate Phase 2: Prophase the nuclear memebrane disintergrates and the spindle is formed. Phase 3:Metaphase the chromosomes line up on the equatorial plate of cell Phase 4: Anaphase the centrioles will separate in animal cells. The chromatids are pulled apart. Phase 5: Telophase cytokinesis occurs (cytoplasm divides) and two new nuclei are formed.
7. Phases of meiosis and how it is different from mitosis.
- meiosis 1: prophase 1, metaphase 1, anaphase 1, and telophase 1
meiosis 2: prophase 2, metaphase 2, anaphase 2, and telophase 2.
It is different from mitosis because mitosis only has one phase not two.
8. Describe the process and purpose of crossing over.
1. What is DNA?
- DNA - the Blueprint of Life
Every living organism contains within itself the information it needs to build a new organism. This information, you could think of it as a blueprint of life, is stored in the organism's genome. The genome is made up of a material called DNA, which stands for deoxyribonucleic acid. If you take a really, really close look at the DNA molecule you will see that it looks like an ordinary ladder, although somewhat twisted. The steps that connects the two strands in this ladder are composed of four different molecules of the same type, called nucleotides.
2. What are the 4 bases?
- In DNA they are A, T, C and G; where A stands for adenine, T for thymine, C for cytosine and finally G for guanine.
3. What 2 peices of information did the scientists need to solve the elusive structure of DNA?
- Phosphate backbone, double helix.
4. What are the specific base pairs?
- (adenine,thynine) (guanine,cytosine)
5. How does the pairing rule effect the shape and structure of DNA?
- Each rung of the twisted ladder in the Helix would be of equal size, and the sugar-phosphate backbone would be smooth.
6. What does the DNA do during cell division?
- It is able to unzip into two pairs.
7. How many base pairs does E. Coli have? How long does it take to replicate? How is the DNA packaged in the cell?
- It makes 4 million pairs in once every 20 minutes and it is curled up in a condensed fashion.
8. How many base pairs does Human DNA have? How long does it take to replicate? How is the DNA packaged in the cell?
- It makes 3 billion pairs in about 12 - 24 hours and is packaged into 23 distinct chromosome pairs.
1. What is RNA? How different is it from DNA?
RNA - a Blueprint Copy
-When an organism needs to use the data stored in the genome, e.g. to build components of a new cell, a copy of the required DNA part is made. This copy is called RNA and is almost identical to DNA. Just like DNA, RNA is an abbreviated form of a chemical name which in the case of RNA is ribonucleic acid.
2. How are the RNA messages formed?
- The alphabet in the RNA molecule contains 4 letters, i.e. A, U, C, G as previously mentioned. To construct a word in the RNA language, three of these letters are grouped together. This three-letter word are often referred to as a triplet or a codon. An example of such a codon is ACG. The letters don't have to be of different kinds, so UUU is also a valid codon. These codons are placed after each other in the RNA molecule, to construct a message, a RNA sequence. This message will later be read by the protein producing machinery in the body. The RNA part to the left contains 39 letters and since each codon contains 3 letters, 13 codons are present (39 letters divided by 3 letters equals 13 words or codons.)
3. How are the RNA messages interpreted?
- Every organism has an almost identical system that is able to read the RNA, interpret the different codons and construct a protein with various combinations of the amino acids mentioned previously. In fact every RNA word or codon, corresponds to one single amino acid. These codons and their correlation with the amino acids in a protein sequence is what defines the genetic code.
1. Describe cell cycle.
- The cell cycle illustrates the different phases of division. The key molecules which control and coordinate cell division are called “CDK” and “Cyclin”. Chromosomes in cell nucleus Gap 1 Phase: Cell growth begins Synthesis Phase: Chromosomes divide and duplicate, Cell growth continues Gap 2 Phase: Cell reaches proper size Mitosis Phase: Cell Division.
2. What is nuclear division.
-
3. What is interphase.
- A stage in the cell cycle when a cell doubles its cytoplasm and synthesizes DNA. Interphase is the "holding" stage or the stage between two successive cell divisions.
4. Cytokinesis.
- Cytokinesis refers to the division of a eukaryotic cell. Cytokinesis usually occurs after a cell has undergone nuclear division as part of mitosis or meiosis. Except for some special cases, the amount of cytoplasm and number of organelles and cellular components in each daughter cell is redistributed equally to each daughter cell. Notable exceptions include oogenesis, where the ovum nearly takes all the cytoplasm and organelles, leaving little for the resulting polar bodies, which then die.
5. Homologous chromosomes.
- A pair of chromosomes made up of two homologs. Homologous chromosomes have corresponding DNA sequences and come from separate parents; one homolog comes from the mother and the other comes from the father. Homologous chromosomes line up and synapse during meiosis.
6. Phases of mitosis (5 of them).
- Phase 1: Interphase the chromosomes replicate Phase 2: Prophase the nuclear memebrane disintergrates and the spindle is formed. Phase 3:Metaphase the chromosomes line up on the equatorial plate of cell Phase 4: Anaphase the centrioles will separate in animal cells. The chromatids are pulled apart. Phase 5: Telophase cytokinesis occurs (cytoplasm divides) and two new nuclei are formed.
7. Phases of meiosis and how it is different from mitosis.
- meiosis 1: prophase 1, metaphase 1, anaphase 1, and telophase 1
meiosis 2: prophase 2, metaphase 2, anaphase 2, and telophase 2.
It is different from mitosis because mitosis only has one phase not two.
8. Describe the process and purpose of crossing over.
Our beautiful hike to Mt. LauLau...on the left is a picture of a Daog plantation up on the mountains. Locals burn up on the mountains to attract deers. The try and attract deers for hunting. The soil up on the mountains then get washed away into the ocean when it rains. The trees and plantation on the mountain is dry due to burning. The picture on the right is taken from from the mountain isn't it beautiful? If we allow hunters to keep burning LauLau beach would not look like this in the nest couple of years. SO PLEASE HELP SAVE THIS BEACH AND MOUNTAIN!!!!!
Monday, October 1, 2007
Photosynthesis is the process where green plants use sunlight, carbon dioxide, and water to make food and oxygen.Respiration is the process where cells use this food to release stored energy.
Photosynthesis: 6CO2 + 6H2O + energy --> 6O2 + C6H12O6
Cellular Respiration: 6O2 + C6H12O6 --> 6H2O + 6CO2 + energy
- Sunlight produces the energy source for Photosynthesis. It uses water and carbon dioxide to make glucose. Cellular Respiration is the opposite of Photosynthesis. It breaks down glucose, using oxygen which creates water and carbon dioxide.
Results are: O2+C6H12O6->H2O+ATP+CO2
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