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.

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.



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