Discovery In 1928 it was discovered by Frederick Griffith in an experiment generally known as transformation.
Experiment
In his experiment he considered two strains of <em>streptococus pneumonia,</em> one was R-type which was non-virulent and cause no disease in mice, other was virulent and S-type which cause disease and at last death of mice.
This experiment was comprised of four steps which are as follow:
Step 1: First he injected living strain of S into mice, after sometime mouce died.
Step 2: He injected living strain of R into mice, the mice alive as he did not got any disease.
Step 3: He injected heat killed strain of S into mice and mice remain alive.
Step 4: He mixed living R strain with heat killed S strain and then inject into mice. As a result the mice died.
Conclusion: It was found that genetic material from heat killed S stain were transferred to living R (non-virulent) strain, as a result R become virulent and cause the death of mice.
Answer:
The Wood
Explanation:
The wood has the most friction because the final speed is less than the others when the fan is on and the cart slowed down the fastest when the fan is turned off.
The cuticle decreases water loss and stomata assist gas exchange. The plants from wet habitats must have a comparatively large number of stomata and thin cuticle. The plants existing in dry habitats must have comparatively few stomata and thick cuticle.
Marshall Nirenberg and Heinrich Mattaeis contributed to out current understanding of the genetic code by discovering genetic codons. Their experiment deciphered the first of the 64 triplet codons in the genetic code by using nucleic acid homopolymer to translate specific amino acids. Their experiment cracked the first codon of the genetic code and showed that RNA controlled the production of certain types of proteins.<span />