<span>It was the culmination of research in the 1930s and early 1940s at the Rockefeller Institute for Medical Research to purify and characterize the "transforming principle" responsible for the transformation phenomenon first described in Griffith's experiment of 1928: killed Streptococcus pneumoniae of the virulent strain type III-S, when injected along with living but non-virulent type II-R pneumococci, resulted in a deadly infection of type III-S pneumococci.</span>
There should be options for this question. I manged to find them elsewhere. They are:
A) the period during which tremendous growth occurs and the organs continue to develop and become functional
B) the period during which the umbilical cord develops
C) the period during which the major organs and structures of the organism first develop
D) the period during which the zygote moves down to the uterus and begins to implant in the lining
The correct answer is C. The embryonic period is the period during which the major organs and structures of the organism first develop. The embryonic period lasts from implantation of the egg in the uterus until about 8 weeks from the time of conception. It is the second major stage of prenatal development, prior to embryonic is the germinal stage and lastly is the fetal stage.
<span>Chlorofluorocarbons
(CFCs) chemicals contain carbon, chlorine and fluorine and is t so expensive at
the same time it’s not flammable, the reason why it is mainly used in business
such as refrigerators and plastics. However, these chemicals destroys our
stratosphere, the second layer of the Earth’s atmosphere and protects us by
blocking the ultraviolet radiation (UV Light). This type of radiation can seep
through organisms skins and can leave destructive effects on DNA molecules
which will also cause skin cancer.</span>
The three main worm phyla are flatworms, roundworms, and segmented worms. Roundworms have a digestive tube that has two openings. Segmented worms have a closed circulatory system in which blood is enclosed in blood vessels. These are important steps in the evolutionary development of animals.
