Down Syndrome.

Down Syndrome.

My blogger assignment will be on Down Syndrome. First of all, Humans normally have 46 chromosomes in our bodies, these chromosomes are in 23 pairs. 22 pairs are alike in both men and women, which are called the "autosomes." The last pair(23rd) are sex chromosomes(X and Y).

Human cells divide in two ways. The first way is ordinary cell division, which is Mitosis, by which the body grows. In this method, one cell becomes two cells which have the exact same number and type of chromosomes as the parent cell. The second method of cell division occurs in the ovaries and testicles, which is Meiosis, and consists of one cell splitting into two, with the resulting cells having half the number of chromosomes of the parent cell. So, normal eggs and sperm cells only have 23 chromosomes instead of 46.

Many errors can occur during cell division. In meiosis, the pairs of chromosomes are supposed to split up and go to different spots in the dividing cell. This event is called "disjunction." However, occasionally one pair does not divide, and the whole pair goes to one spot. This means that in the resulting cells, one will have 24 chromosomes and the other will have 22 chromosomes. This accident is called "nondisjunction." If a sperm or egg with an abnormal number of chromosomes merges with a normal mate, the resulting fertilized egg will have an abnormal number of chromosomes.

In Down syndrome, 95% of all cases are caused by this event: one cell has two 21st chromosomes instead of one, so the resulting fertilized egg has three 21st chromosomes. That's why they call it Trisomy 21. Recent research has shown that in these cases, approximately 90% of the abnormal cells are the eggs. The cause of the nondisjunction error isn't known, but there is definitely connection with maternal age. Research is currently aimed at trying to determine the cause and timing of the nondisjunction event.

I found my research at this website. CLICK ME!

Cancer Will Come Back, Just Like It Came Back For My Cousin...

There are more than one-hundred different types of CANCER. Follow me! These are the different types of CANCERS that you can get:
~CARCINOMA- CANCER that begins in the skin. It can also begin in tissues that line or cover internal organs.
~SARCOMA- CANCER that begins in connective/supportive tissues such as bone, cartilage, fat, muscle, or blood vessels.
~LEUKEMIA- CANCER that starts in tissue that forms blood, such as the bone marrow. It produces large numbers of abnormal blood cells and enters the blood.
~LYMPHOMA and MYELOMA- CANCERS that are made in the cells of the immune system. ~CENTRAL NERVOUS SYSTEM CANCERS- CANCERS that are made in the tissue of the brain and/or spinal cord. Research shoes that there is a maximum of 100,000 victims diagnosed with CANCER per year. That's a lot of people! Follow this link to learn more. In fact, my cousin, AnnaMaria Kakis, died two years ago at the age of 19 years old. She suffered from LYMPHOMA. She had it ever since she was born. Then it left her for good, or so we thought. Turns out, she was in remission. So, make sure that if you have CANCER to get it treated as soon as possible, even if you think it's going away. It will come back, just like it came back for my cousin...

Lucifer The Snail<3

hi, I'm Irene Mavroudis. I am in Mr. Olson's Biology Class at Mills High School. We did a experiment on snails. I got teamed up with Brittany and Maeyra. We names our Snail, Lucifer. He was small and cute. I fed him lettuce and we noticed that it had black teeth/mouth. We placed him on a concave lense of some type and pointed him near the light and looked at the bottom of the lense and saw wave-like movements under his foot. This is what allows him to move. We also noticed that at the end of his antenna-like eyes, there was a tiny, black dot...which was his eye. I hope that Mr. Olson gives us more fun experiments to do!!!