The changes in foot structure in a bird population over. Evolution leads to less complex organisms. And also the lock-and-key model.
Answer:
2.5 billion years ago.
Explanation:
Evolutionary tree is constructed to understand the phylogeny and evolution relationship of the organism. The evolutionary tree is constructed by looking at the molecular and physiology of the different organisms.
The eukaryotes are more closely related to the archaea. Depending on the biochamical and molecular evidence is has been found that they share the common ancestor almost 2.5 billion years ago. This can also be deduced by the fossil evidence as well.
Thus, the answer is 2.5 billion years ago.
Since there are no given choices, I would just compare and contrast DNA and RNA. These are the two types of nucleic acids in the human body. The structural unit of nucleic acids are composed of repeating units of monomers called nucleotides. Nucelotides are composed of three functional groups: sugars which are specifically pentoses (5-Carbon sugars), phosphate group and nitrogenous base.
Now, the RNA and DNA differ in the composition of these sugars and the bases. Based on the nitrogenous bases and sugar, the DNA has a deoxyribose as the sugar and its 4 bases are adenine, guanine, cytosine and thymine. For RNA, the sugar is ribose while its 4 bases are <span>adenine, guanine, cytosine, and uracil.
They also differ in their structure. </span>DNA is a double stranded β-helix with a long chain of nucleotides. RNA is composed of a shorter chain with a single strand α-helix structure.
Lastly, they differ in their functions. T<span>he DNA is responsible for storing the genetic information while the RNA is responsible for transporting the genetic information to the ribosomes which synthesize proteins.</span>