Proteins are formed from monomers called amino acids. These are naturally found substances that polymerize in order to form proteins. These are compounds which has amine and carboxyl groups and are characterized by an R-group. In proteins, there are about 20 amino acids that can be found.
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.
TRUE. the placenta develops in the mother's uterus during pregnancy. The structure provides oxygen and nutrients to the growing baby and removes waste products from the babys blood
Answer: B. False
Explanation:
“Hox” genes are a highly conserved group of genes, all of whose products are transcription factors bearing a specific domain (called a ”homeodomain”). The transcriptional activity of a large amount of genes relevant to embryonic development is controlled by regulatory sites which are able to bind to this domain. Changes in the transcriptional activity of even a single Hox gene may thus have dramatic downstream effects on the phenotype, as this will result in several further genes having their transcription either enhanced or suppressed.