Question

evidence for evolution: molecular evidence
compare the dna sequences of these mammals and then answer the questions.
mouse a t g g c a a t a c c c t t g g
elephant a t g a c a a a a c a c t g g c
zebra a t g g c a a t a c a c a t g g

1. how many bases are different between the mouse and the elephant?
2. how many bases are different between the mouse and the zebra?
3. how many bases are different between the elephant and the zebra?
4. which two animals are most closely related? support your answer.

Explanation:

Step1: Compare mouse and elephant sequences

Count the different bases. Mouse: A T G G C A A T A C C C T T G G, Elephant: A T G A C A A A A C A C T G G C. There are 5 different bases.

Step2: Compare mouse and zebra sequences

Mouse: A T G G C A A T A C C C T T G G, Zebra: A T G G C A A T A C A C A T G G. There are 3 different bases.

Step3: Compare elephant and zebra sequences

Elephant: A T G A C A A A A C A C T G G C, Zebra: A T G G C A A T A C A C A T G G. There are 4 different bases.

Step4: Determine most - related animals

The fewer the base - differences, the more closely related. Since mouse and zebra have the fewest (3) base - differences, they are most closely related.

Answer:

1. 5
2. 3
3. 4
4. Mouse and zebra. They have the fewest number of different DNA bases (3) among the pairs compared.