The table below shows the number of nucleotide differences between a region of mitochondrial DNA in humans, chimpanzees and a Neanderthal - VCE - SSCE Biology - Question 6 - 2003 - Paper 1
Question 6
The table below shows the number of nucleotide differences between a region of mitochondrial DNA in humans, chimpanzees and a Neanderthal.
| | Human 2 | Chimp... show full transcript
Worked Solution & Example Answer:The table below shows the number of nucleotide differences between a region of mitochondrial DNA in humans, chimpanzees and a Neanderthal - VCE - SSCE Biology - Question 6 - 2003 - Paper 1
Step 1
a. Based on the data in the table, which individual is most closely related to the Neanderthal?
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Answer
Human 1 has the fewest nucleotide differences (20) from the Neanderthal, making it the individual most closely related to the Neanderthal.
Step 2
b. Explain why 77 nucleotide differences is a minimum number of base substitutions.
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Answer
The 77 nucleotide differences represent the total accumulated changes between the two DNA sequences. Since mutations can be reversible, some of these differences may revert back to an earlier nucleotide. Thus, the actual number of base substitutions could be fewer than 77.
Step 3
c.i. What other type of information obtained from the fossil could be used to assist in determining the evolutionary relationship of Neanderthals with humans and chimpanzees?
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Answer
Skeletal structure/morphology can provide crucial information about the physical characteristics and evolutionary relationships of Neanderthals with modern humans and chimpanzees.
Step 4
c.ii. What method would be used to estimate the absolute age of the Neanderthal fossil?
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Answer
Carbon dating can be used to estimate the absolute age of the fossil, as it is approximately 25,000 years old.
Step 5
c.iii. What method could be used to determine the relative age of the Neanderthal fossil?
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Answer
To determine the relative age of the fossil, stratigraphy can be used, which states that the oldest stratum is at the bottom and younger layers lie above older ones.
