Saturday, July 28, 2012

STPM Biology - chapter 2: Revision essay question 4


4. Distinguish bacteria chromosome from a eukaryotic chromosome.

Answer:

Chromosome is defined as a threadlike structure several to many which found in the nucleus. Chromosomes are composed of chromatin and carry genes, that is deoxyribonucleic acid (DNA).The eukaryotic cell such as animal cell and plant cell contains fins thread like structures called chromatin. Chromatin is made up of DNA and histone protein. The chromatin threads looked shorter and thicker during first phrase of mitosis when seen under the light microscope.  At this stage the chromatin is called chromosome. The chromosome is multiple linear which are DNA molecules wrapped around beads of histone protein. However, compared to the prokaryotic cells such as bacteria and cyanobacteria consists a single circular or “naked” DNA molecule compacted into nucleiod, that is, DNA not combine with protein.


Assignment submitted by S.M., Kang, E.S., Ong, T.W., Tan, K.Y., Ho. X.H., Wong 2011/2012 (IBM)


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