A chromosome has the following segments, where ● represents the centromere: M N O ● P Q R S T. The chromosome sequences resulting from the following mutations are: a. Deletion of MN: O ● P Q R S T b. Pericentric inversion of NOP: P N O ● M Q R S T c. Inversion of RS, followed by tandem duplication of QRST: M N O ● P Q T S R Q R S T

Let's break down the given chromosome segments and the resulting sequences after the mentioned mutations:

Original Chromosome Sequence: M N O ● P Q R S T

a. Deletion of MN: O ● P Q R S T

• This mutation involves the deletion of MN from the original sequence, resulting in the sequence O ● P Q R S T.

b. Pericentric inversion of NOP: P N O ● M Q R S T

• Pericentric inversion involves a reversal of a chromosome segment, including the centromere.
• The sequence NOP gets inverted to PNO, so the segment before the centromere is rearranged, resulting in the sequence P N O ● M Q R S T.

c. Inversion of RS, followed by tandem duplication of QRST: M N O ● P Q T S R Q R S T

• Inversion of RS: The segment RS gets inverted, resulting in the sequence M N O ● P Q R S T.
• Tandem duplication of QRST: After the inversion of RS, the segment QRST gets duplicated, resulting in the sequence M N O ● P Q T S R Q R S T.

Therefore, summarizing the mutations:

a. Deletion of MN: O ● P Q R S T

b. Pericentric inversion of NOP: P N O ● M Q R S T

c. Inversion of RS, followed by tandem duplication of QRST: M N O ● P Q T S R Q R S T