Question

An analysis of DNA and RNA sequences can be used to classify organisms. A dendrogram, such as

the one shown below, is based on molecular data. It can be used to represent evolutionary
relationships within a group of organisms that are hypothesized to have descended from a common
ancestor.
Brown bear
Sun bear
Spectaded bear
Giant panda
Lesser panda
Raccoon
Dog
100 50 60 40 20
Millions of Years Ago
Which statement is best supported by the information in this dendrogram?
A. Lesser pandas are more genetically similar to giant pandas that they are to raccoons.
B.Brown bears are more genetically similar to giant pandas than they are to sun bears.
C.Lesser pandas are more genetically similar to raccoons than they are to giant pandas.
D. The bear species are all more genetically similar to dogs than they are to giant pandas.

Answer 1

Answer C is supported by the dendrogram, as it shows that lesser pandas are more genetically similar to raccoons than to giant pandas due to a more recent common ancestor. Molecular comparisons aid in classifying organisms based on their evolutionary relationships.

Step-by-step explanation:

C. Lesser pandas are more genetically similar to raccoons than they are to giant pandas. This conclusion comes from analyzing the molecular data and using the dendrogram to infer evolutionary relationships. The dendrogram shows the points in time where different species have diverged from common ancestors, meaning that the lesser panda and the raccoon share a more recent common ancestor than the lesser panda and the giant panda.

Molecular comparisons and advancements in DNA technology have significantly improved the practice of molecular systematics. By examining differences in DNA and RNA sequences, scientists can organize organisms based on evolutionary relationships. The assumption is that the more similar the sequences between two organisms, the more closely related they are, since changes in the sequences accumulate over time. It is important to remember that phylogenetic trees, such as dendrograms, are considered hypotheses, and as new evidence comes to light, they are subject to change.