(a)+Chromosomes

Mana

// **Chromosomes** //
A chromosome is a coiled DNA molecule within a cell’s nucleus that carries an individual’s GENETIC CODE. Each organism has a distinct number of chromosomes, in humans, every cell contains 46 chromosomes. 23 chromosomes are from the father and the other 23 chromosomes are from the mother //.(秀雄)// One chromosome from the father and one chromosome from the mother will be combined together to form a pair of chromosomes. Other organisms have different numbers, for instance, a dog has 78 chromosomes per cell.. Chromosomes also contain proteins that are bound in DNA. These help the packaging of the DNA and the controlling of the DNA's functions. //(Chromosomes)// //Other animals that are known to have the same number of chromosomes as humans are the Reeves's Muntjac and the Sable Antelope both with 46 chromosomes. The Reeves's Muntjac is a specie of Muntjac that lives mostly in southeastern China. The Sable Antelope on the other hand lives in East Africa, the south of Kenya and Southern Africa. Here are pictures of the Reeves's Muntjac and Sable Antelope:// //The Reeves's Muntjac The Sable Antelope//

the structure of the chromosome//.(// //Pickering)//



the three-dimentional diagram of chromosome.

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// **Karyotype** //

A karyotype is a number and the visual appearance of a person's (or fetus) chromosomes. A karyotype is often done to determine if the offspring has the correct number of chromosomes. This karyotype is used to observe and analyze chromosomal errors. If there are missing chromosomes (monosomy), or extra chromosomes (trisomy or polydactyl); or if individual chromosomes have extensions or deletions; the subject will then have a chromosomal disorder. Having the incorrect number of chromosomes indicates that the child will have a disability such as Down Syndrome. //(Oszust)//

In a karyotype, each chromosome is arranged by size and therefore the order is from largest to smallest. The reason for this arrangement of the chromosome is because by doing so, scientists are able to quickly identify alterations in the chromosomes that could lead to a genetic disorder as mentioned above. This process is also known as the organization of chromosomes in karyograms. Human autosomes, non-sex chromosomes, contain chromosomes numbered from 1-22 in decreasing size order, however, with the exception of #21 being smaller than #22. The sex chromosomes are usually placed at the end of the karyogram.In order to make it easier to detect the structural details of a chromosome, scientists have invented stains which create different banding patterns for each chromosome by binding with the DNA.Scientists can detect aneuploidy (when there is one more or less chromosome), subtle deletions/insertions that are different from the normal banding patterns, and translocations through the use of karyotypes.

//The karyotype in the male cell.//

// Eukaryotes  //

Eukaryotes contain multiple linear chromosomes contained in the cell's nucleus. The nucleus contains all the Eukaryote cell DNA, for instance the Mitochondria is where energy is generated. Nearly all other life forms are eukaryotes. They are cells with nuclei, which can be found in animals, plants and yeast.



Unlike the eukaryotes, prokaryotes lack a nucleus or any membrane-bound organelles. This means that the DNA within a prokaryote is less structures than that of a eukaryote. Additionally, the DNA in a prokaryote is shaped like a single circular loop.

[[image:http://www.earthlife.net/prokaryotes/images/bacteria1.gif width="400" height="208"]]
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Works Cited

"Chromosomes and DNA." __The Biology Corner__. 05 Feb. 2012 [].

Oszust, Steven. "What is the purpose of Karyotyping?" __Columbia University Summer Research Program__. Aug. 2004. 05 Feb.2012 [].

Pickering, W. R. "Chapter 11." __Complete biology__. Oxford: Oxford UP, 2000.

"Gordon's Introduction to The Kindoms of Life." // The Earth Life Web //. Web. 06 Feb. 2012. [].

秀雄, 毛利. __高等学校　生物　１__. 東京都: 三省堂.

"Karyotyping | Learn Science at Scitable." //Nature Publishing Group : Science Journals, Jobs, and Information//. Web. 14 Feb. 2012. [].

"Make a Karyotype." //Learn.Genetics™//. Web. 14 Feb. 2012. [].

"Prokaryotes and Eukaryotes - Comparing Prokaryote and Eukaryote Cells." // Animals Wildlife - Animal Facts, Animal Pictures, Habitat Facts, Evolution and Zoology //. Web. 09 Feb. 2012. [].

"The Earth Life Web, Welcome to the Miniature World of the Prokaryotes." // The Earth Life Web //. Web. 09 Feb. 2012. [].

"What Is a Chromosome?" //THE MEDICAL NEWS | from News-Medical.Net - Latest Medical News and Research from Around the World//. Web. 09 Feb. 2012. [].

__Learn Biology: CellsâProkaryotic Cells vs. Eukaryotic Cells__. Dir. Mahalodotcom. Perf. Mary Poffenroth. __YouTube__. 11 Feb. 2011. Google Inc. 16 Feb. 2012 [].

__How DNA is Packaged (Advanced)__. Dir. DNALearningCenter. __YouTube__. 22 Mar. 2010. 16 Feb. 2012 [].

ilson, Don E. "Reeves's Muntjac." __Wikipedia, the free encyclopedia__. 13 Jan. 2012. Wikipedia Foundation. 16 Feb. 2012 [].

"Sable Antelope." __Wikipedia, the free encyclopedia__. 19 Jan. 2012. Wikipedia Foundation. 16 Feb. 2012 [].