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The tetranucleotide hypothesis of Phoebus Levene [1] proposed that DNA was composed of repeating sequences of four nucleotides. [2] It was very influential for three decades, and was developed by Levene at least into the 1910, and the diagram at the right illustrates the view of Levene and Tipson. [3] In 1940, at the time of Levene's death ...
Phoebus Aaron Theodore Levene (25 February 1869 – 6 September 1940) was a Russian-born American biochemist who studied the structure and function of nucleic acids. He characterized the different forms of nucleic acid, DNA from RNA , and found that DNA contained adenine , guanine , thymine , cytosine , deoxyribose , and a phosphate group.
Hershey–Chase experiment. The Hershey–Chase experiments were a series of experiments conducted in 1952 [1] by Alfred Hershey and Martha Chase that helped to confirm that DNA is genetic material. While DNA had been known to biologists since 1869, [2] many scientists still assumed at the time that proteins carried the information for ...
According to Phoebus Levene's influential "tetranucleotide hypothesis", DNA consisted of repeating units of the four nucleotide bases and had little biological specificity. DNA was therefore thought to be the structural component of chromosomes , whereas the genes were thought likely to be made of the protein component of chromosomes.
For this research, Chargaff is credited with disproving the tetranucleotide hypothesis [14] (Phoebus Levene's widely accepted hypothesis that DNA was composed of a large number of repeats of GACT). Most researchers had previously assumed that deviations from equimolar base ratios (G = A = C = T) were due to experimental error, but Chargaff ...
Levene's test. In statistics, Levene's test is an inferential statistic used to assess the equality of variances for a variable calculated for two or more groups. [1] This test is used because some common statistical procedures assume that variances of the populations from which different samples are drawn are equal.
William Kruskal. Bonnie Ray. Howard Levene (January 17, 1914 – July 2, 2003) [1] was an American statistician and geneticist. He received his Ph.D. from Columbia University in 1947, and joined the faculty there shortly thereafter. He remained on the faculty at Columbia, where he served as professor of mathematical statistics and genetics ...
Bartlett's test is used to test the null hypothesis, H0 that all k population variances are equal against the alternative that at least two are different. If there are k samples with sizes and sample variances then Bartlett's test statistic is. where and is the pooled estimate for the variance. The test statistic has approximately a distribution.