Lian Beng from Spinning Top to Inverted Hammer

Inverted hammer waiting for confirmation. Immediate resistance is the red downtrend line followed by the 20 days EMA resistance line. Breakout above 20 days EMA will propel price towards 43 cents the recent peak and provide momentum to establish a new higher peak. Immediate support is 34 to 31.5 cents band formed during the recent low in March 2008. Major support is at 30 cents and support failure here will result in further downslide.

Karyotype

Main article: Karyotype

Figure 3: Karyogram of a human male

In general, the karyotype is the characteristic chromosome complement of a eukaryote species.^[36] The preparation and study of karyotypes is part of cytogenetics.

Although the replication and transcription of DNA is highly standardized in eukaryotes, the same cannot be said for their karotypes, which are often highly variable. There may be variation between species in chromosome number and in detailed organization. In some cases there is significant variation within species. Often there is variation 1. between the two sexes. 2. between the germ-line and soma (between gametes and the rest of the body). 3. between members of a population, due to balanced genetic polymorphism. 4. geographical variation between races. 5. mosaics or otherwise abnormal individuals. Finally, variation in karyotype may occur during development from the fertilised egg.

The technique of determining the karyotype is usually called karyotyping. Cells can be locked part-way through division (in metaphase) in vitro (in a reaction vial) with colchicine. These cells are then stained, photographed and arranged into a karyogram, with the set of chromosomes arranged, autosomes in order of length, and sex chromosomes (here XY) at the end: Fig. 3.

Like many sexually reproducing species, humans have special gonosomes (sex chromosomes, in contrast to autosomes). These are XX in females and XY in males.

Historical note

Investigation into the human karyotype took many years to settle the most basic question: how many chromosomes does a normal diploid human cell contain? In 1912, Hans von Winiwarter reported 47 chromosomes in spermatogonia and 48 in oogonia, concluding an XX/XO sex determination mechanism.^[37] Painter in 1922 was not certain whether the diploid number of man was 46 or 48, at first favouring 46.^[38] He revised his opinion later from 46 to 48, and he correctly insisted on man having an XX/XY system.^[39] Considering their techniques, these results were quite remarkable.

New techniques were needed to definitively solve the problem:

1. Using cells in culture

2. Pretreating cells in a hypotonic solution, which swells them and spreads the chromosomes

3. Arresting mitosis in metaphase by a solution of colchicine

4. Squashing the preparation on the slide forcing the chromosomes into a single plane

5. Cutting up a photomicrograph and arranging the result into an indisputable karyogram.

It took until the mid 1950s until it became generally accepted that the karyotype of man included only 46 chromosomes.^[40][41] Rather interestingly, chimpanzees (our closest living relatives) have 48 chromosomes.

http://en.wikipedia.org/wiki/Chromosome