<span>The two scientists, who are credited with creating the first accurate model of DNA are JAMES WATSON and FRANCIS CRICK. The success that these two scientists achieved concerning DNA structure is based on the works of other scientists, who have carried out series of research on DNA. The real proof of Watson - Crick model for DNA was released in 1982, this was after the B form of DNA was crystallized and its X ray pattern was solved.</span>
Cladogram is a diagram that tells the relationships between different groups of taxa called “clades”. Cladogram gives phylogeny (evolutionary history) of the taxa. The organisms which share derived characteristics are grouped together while constructing a cladogram. Jelly fish is a cnidarian share common characteristics such as radial symmetry, simple tissues and no body organs with other members like corals and sea anemones.
<h3><u>Answer;</u></h3>
d. before the Neogene era.
<h3><u>Explanation;</u></h3>
- <em><u>The Silurian Period was a third period of the Paleozoic Era that occurred from 443 million to 416 million years ago. This period occurred after the Ordovician Period and was then followed by the Devonian Period.</u></em>
- Silurian period is the period that many biologically significant events took place. There was a widespread radiations of crinoids, continued priliferation and expansion of the brachiopods and also the oldest known fossils of coral reefs.
The correct option is D.
A scientific theory refers to an in depth explanation of a specific observed phenomenon while a scientific law refers to a statement about a particular observed phenomenon. Scientific laws are usually presented in form of mathematical expressions for the observed phenomenon; examples of these are Newton's law of gravity, Mendel's law of independent assortment, etc. Scientific law basically describes the observations that are made and these observations are usually similar to other related observations.
