Mutations Worksheet for students to practice identifying and classifying genetic mutations in DNA sequences.

Problem Analysis:

The task involves analyzing a series of mutations in a DNA sequence and determining the type of mutation (insertion, deletion, or substitution) that occurred at each step. The original DNA sequence is provided, along with subsequent mutated sequences. The goal is to identify the changes and classify them as insertions, deletions, or substitutions.

#### Given Data:
1. Original DNA Sequence: `TACCTCGGCAAGCCT`
2. Mutated DNA Sequences:
- Sequence #1: `TACACTTGCGGAAGACT`
- Sequence #2: `TACACCTTGCGGAAGACT`
- Sequence #3: `TACACTTAGCGGAAGACT`
- Sequence #4: `TACACCTTAGCGGAAGACT`
- Sequence #5: `TACACCTTTGCGGAAGACT`

#### Questions to Answer:
1. What type of mutation is responsible for obliterating a DNA strand?
2. What type of mutation would be an alteration of a DNA strand?
3. What type of mutation doesn't change the length of a DNA strand?

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Step-by-Step Solution:

#### 1. Analyze Each Mutation:
We will compare each mutated sequence with the original sequence to identify the changes.

##### Original Sequence: `TACCTCGGCAAGCCT`

##### Sequence #1: `TACACTTGCGGAAGACT`
- Comparison:
- Original: `TACCTCGGCAAGCCT`
- Mutated: `TACACTTGCGGAAGACT`
- Change: The base `T` at position 6 has been replaced by `A`.
- Type of Mutation: Substitution (a single base change).

##### Sequence #2: `TACACCTTGCGGAAGACT`
- Comparison:
- Original: `TACCTCGGCAAGCCT`
- Mutated: `TACACCTTGCGGAAGACT`
- Change: An additional `A` has been inserted after the first `C`.
- Type of Mutation: Insertion (an extra base added).

##### Sequence #3: `TACACTTAGCGGAAGACT`
- Comparison:
- Original: `TACCTCGGCAAGCCT`
- Mutated: `TACACTTAGCGGAAGACT`
- Change: The base `G` at position 9 has been replaced by `A`.
- Type of Mutation: Substitution (a single base change).

##### Sequence #4: `TACACCTTAGCGGAAGACT`
- Comparison:
- Original: `TACCTCGGCAAGCCT`
- Mutated: `TACACCTTAGCGGAAGACT`
- Change: An additional `A` has been inserted after the first `C`, and the base `G` at position 9 has been replaced by `A`.
- Type of Mutation: Insertion + Substitution (extra base added and a base changed).

##### Sequence #5: `TACACCTTTGCGGAAGACT`
- Comparison:
- Original: `TACCTCGGCAAGCCT`
- Mutated: `TACACCTTTGCGGAAGACT`
- Change: The base `G` at position 9 has been replaced by `T`.
- Type of Mutation: Substitution (a single base change).

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#### 2. Answer the Questions:

1. What type of mutation is responsible for obliterating a DNA strand?
- Deletion: A deletion removes one or more bases from the DNA strand, which can disrupt the reading frame and potentially render the strand non-functional.

2. What type of mutation would be an alteration of a DNA strand?
- Substitution: A substitution replaces one base with another, altering the sequence but not necessarily disrupting the length or reading frame.

3. What type of mutation doesn't change the length of a DNA strand?
- Substitution: A substitution only replaces one base with another, so the overall length of the DNA strand remains unchanged.

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Final Answers:

1. Deletion
2. Substitution
3. Substitution

Boxed Final Answer:

\[
\boxed{\text{Deletion, Substitution, Substitution}}
\]