Thursday, October 28, 2010

Retreat blog post:

1. What did the retreat mean to me?

It meant bonding people I don't know, and create new friendships. I definitely think that I met that goal on this retreat. I watched the movie 'Groundhog Day' and responded to it, and I think the movie had a lot behind it: a lot of deeper meanings... I think that the retreat helped me become a better leader, follower, and team member.

2. What did I learn about myself?

I learned that I could do many things that I didn't think I could do! I learned that I could shoot  a bow and arrow, and that I could steer a boat from the stern. I thought that the saying, "if you put your mind to it, anything is possible" but now I understand, that it is, in fact, a true statement.

3. What connections to science did I find or here or make with any experience I had?

In the high ropes, when Leora was climbing the ladder, she told me to twist the ladder so that she could continue climbing. I twisted the ladder a little bit, and then more and more until she continued to climb. 
When I looked up, the ladder was forming a DNA shape! I told Mr. Chrystal as soon as I found it.

Thursday, October 14, 2010

Definitions for P-M-A-T

P= Prophase: the nuclear envelope disappears and replicated chromosomes coil together into X - shaped chromosomes.

M= Metaphase: the tugging of the spindle fibres pulls the chromosomes into a single line across the middle of the cell.

A= Anaphase: The spindle fibres begin to contract and shorten. This action pulls the centromere apart, allowing the sister chromatids to move to opposite pole of the cell. Once they separate, each sister chromatid is considered as a chromosome.

T= Telophase: final stage of mitosis. one complete set of chromosomes stand at each pole of the cell. the spindle fibres begin to disappear, and a nuclear membrane forms around each set of chromosomes. Now there are two nuclei in one cell. the cell is ready to divide.

SCIENCE 5 QUESTIONS:

By: Noahm Rozen

1. What is a chromosome made of?
DNA and genes.

2. How many chromosomes are there in one human cell?
46 chromosomes or 23 pairs. The 23rd pair tells us if you are male or female.

3. What organelle makes protein?
the ribosomes make the protein for the cells.

4. a) How would the bases A, C, G and T be paired in DNA? 
Answer: A always pairs with T,  C always pairs with G.
   b) If ATTGTCACCTG was the sequence of one side of a part of DNA, what would the other side be?
Answer: TAACAGTGGAC.

5. What is the name of the messenger that carries the information to make protein from the DNA?
mRNA is the messenger that actually SENDS ITSELF to the ribosomes with the information to make proteins.

Tuesday, October 12, 2010

science mutation questions/answers by Noahm Rozen

1. It is important to protect these bears since black bears can carry the mutated gene for a spirit. So by protecting the black bears we are also protecting the spirit bears.

2. a) G is substituted for C
    b) A is missing at the end of the sequence
    c) There is an extra G in the sequence

3. Positive, neutral, and negative mutations.

4. For a whale, instead of having a blowhole on his face (nose) from a long time ago, now it has one on top of its head. It helps him so that he doesn't have to come up all the way for air, he just needs to get the top of his head out. The whale adapted to its environment over time.

5. the mutation is bad. The cell is half of what it was before and it is a negative mutation.

6. Because having black or white fur does not affect the bear. Only the genes are affected.

7. It could be a neutral or negative mutation like you have a hand and if a certain letter is taken away from the sequence, then the hand could lose its mobility.

8. to replace a defective gene with a normal copy of the same gene in attempt to restore it with a gene that works.

Tuesday, October 5, 2010


Science Notes (textbook pgs. 120-132)
By: Noahm Rozen

CELLS AND ORGANELLES

PLANT CELLS:

Cell wall – a tough rigid structure surrounding the cell membrane. Provides support for the plant cell.

Chloroplast – an organelle that traps energy from the sun and uses it as energy for the plant cells.

Vesicles – membrane covered sacs that form off the ends of the endoplasmic reticulum. Vesicles transport new proteins to the Golgi
Body for further processing and export out of the cell.

BOTH (animal and plant cells):
Cell membrane – a thin covering that goes over a cell, controls what goes in and out of the cell

Cytoplasm – a jelly-like substance that contains the organelles and other life-supporting materials such as water and sugar.

Mitochondria (p)/mitochondrion (s) – organelles that are specialized to provide energy for cells by engaging sugar called glucose into usable energy.

Ribosomes – are small organelles that do not have a membrane. Some float in cytoplasm, others are attached to the endoplasmic reticulum.

Proteins – are essential materials required for cells to carry out the activities necessary for survival.

Endoplasmic reticulum – a network of membrane-covered channels within a cell. The organelle acts as a transport system for materials made in the cell.

Golgi Body – a specialized organelle that sorts and packages proteins for transport.

Vacuole – a membrane covered storage within cells. Plant cells often contain small vacuoles to store starch and a large one to store water. Some animal cells have vacuoles.

NUCLEUS (plural nuclei) – the organelle that controls all the activities of cell parts described above.

THE NUCLEUS:

Nuclear membrane – surrounds the nucleus, is similar to the structure of the cell membrane. The nuclear membrane protects the contents of a nucleus.

Nucleolus – a membrane free organelle that floats in the interior of the nucleus. The function of the nucleolus is to make ribosomes.

Nuclear pores – openings in the nuclear membrane that allow only certain materials into and out of the nucleus. Ribosomes made in the nucleus will leave through the pores and go to the cytoplasm or endoplasmic reticulum.
DEOXYRIBONUCLEIC ACID (DNA)

The instructions in the nucleus are carried in long two-stranded molecules called DNA. It looks like a twisted ladder (as seen above). Scientists call it the double helix.
·      The sides of the DNA ladder are made of sugar
·      The “steps” of the ladder are made of four nitrogen bases, which are represented by letters.
·      The letters are: A (adenine), G (guanine), C (cytosine), and T (thymine)
Everything that occurs within a cell is the result of how the bases on the DNA molecule are arranged. Bases in a DNA molecule always join in a specific way:
·      A always joins with T
·      G always joins with C
The order and number of these bases can vary within the DNA molecule.
In humans, single DNA molecule can be several million base pairs in length.

DNA IS STORED IN CHROMATIN:
Most of the time, DNA exists in the nucleus as chromatin
Chromatin – a substance that contains DNA and proteins.
Within each strand of chromatin is one molecule of DNA. When a cell is growing, the DNA is uncoiled and helps in the distribution of proteins the cell requires.

EVERY ORGANISM HAS A CERTAIN NUMBER OF CHROMOSOMES:
Most human cells have 46 chromosomes arranged in 23 pairs, including one pair that helps determine gender. For males the 23rd pair is the XY pair, and for females it’s the XX pair.

GENES ARE FOUND ON CHROMOSOMES:
Genes – small segments of DNA located at specific places on a chromosome.