Question
Genetic Mutations
Mutation as a process that creates genetic variation. Mutation creates variations in protein-coding portions of genes that can affect the protein itself. More often, it creates variations in the switches that control when and where a protein is active and how much protein is made.
For example: lactase is an enzyme that helps infants break down lactose, a sugar in milk. Normally the gene that codes for lactase is active in babies and then turned off at about age four. When people who do not make lactase consume milk, they experience discomfort. But some people have a variation in a genetic switch that keeps the lactase gene active and people who have it can keep milk in their diets even as adults.
Mutations are a source of genetic variation. Mutations that occur in sex cells or gametes, can be passed from one generation to the next. Mutations that occur in somatic or body cells, like a mutation causing skin cancer, will not be passed on. Mutations can be classified as harmful, as is the case of the sickle cell gene, beneficial, or having no impact on the organism at all, neutral.
Most of the mutations in our DNA are naturally-occurring. For example, when a cell divides, it makes a copy of its DNA and sometimes the copy is not perfect. That small difference from the original DNA sequence is a mutation. Mutations can also be caused by exposure to specific chemicals or radiation; mutagens.
There are many different ways that DNA can be changed, resulting in different types of mutation.
Substitution
A substitution is a mutation that exchanges one base for another. A substitution could:
~change a codon to one that encodes a different amino acid and cause a small change in the protein produced. For example, sickle cell anemia is caused by a substitution in the beta-hemoglobin gene, which alters a single amino acid in the protein produced.
~change a codon to one that encodes the same amino acid and causes no change in the protein produced. These are called silent mutations.
~change an amino-acid-coding codon to a single "stop" codon and cause an incomplete protein. This can have serious effects since the incomplete protein probably won't function.
Insertion
Insertions are mutations in which extra base pairs are inserted into a new place in the DNA.
Deletion
Deletions are mutations in which a section of DNA is lost, or deleted.
Question 1
PART A
When DNA replication occurs before meiosis, the original DNA strand CAG TGT TTA TAG is copied into complementary strand GTC ACA GGC ATC. What type of mutation has occurred?
Responses
A deletiondeletion
B insertioninsertion
C inversioninversion
D substitutionsubstitution
Question 2
PART B
When DNA replication occurs before meiosis, the original DNA strand GTC ACA GGC ATC is copied into complementary strand CAG CCG TAG. What type of mutation has occurred??
Responses
A deletiondeletion
B insertioninsertion
C inversioninversion
D translocationtranslocation
Mutation as a process that creates genetic variation. Mutation creates variations in protein-coding portions of genes that can affect the protein itself. More often, it creates variations in the switches that control when and where a protein is active and how much protein is made.
For example: lactase is an enzyme that helps infants break down lactose, a sugar in milk. Normally the gene that codes for lactase is active in babies and then turned off at about age four. When people who do not make lactase consume milk, they experience discomfort. But some people have a variation in a genetic switch that keeps the lactase gene active and people who have it can keep milk in their diets even as adults.
Mutations are a source of genetic variation. Mutations that occur in sex cells or gametes, can be passed from one generation to the next. Mutations that occur in somatic or body cells, like a mutation causing skin cancer, will not be passed on. Mutations can be classified as harmful, as is the case of the sickle cell gene, beneficial, or having no impact on the organism at all, neutral.
Most of the mutations in our DNA are naturally-occurring. For example, when a cell divides, it makes a copy of its DNA and sometimes the copy is not perfect. That small difference from the original DNA sequence is a mutation. Mutations can also be caused by exposure to specific chemicals or radiation; mutagens.
There are many different ways that DNA can be changed, resulting in different types of mutation.
Substitution
A substitution is a mutation that exchanges one base for another. A substitution could:
~change a codon to one that encodes a different amino acid and cause a small change in the protein produced. For example, sickle cell anemia is caused by a substitution in the beta-hemoglobin gene, which alters a single amino acid in the protein produced.
~change a codon to one that encodes the same amino acid and causes no change in the protein produced. These are called silent mutations.
~change an amino-acid-coding codon to a single "stop" codon and cause an incomplete protein. This can have serious effects since the incomplete protein probably won't function.
Insertion
Insertions are mutations in which extra base pairs are inserted into a new place in the DNA.
Deletion
Deletions are mutations in which a section of DNA is lost, or deleted.
Question 1
PART A
When DNA replication occurs before meiosis, the original DNA strand CAG TGT TTA TAG is copied into complementary strand GTC ACA GGC ATC. What type of mutation has occurred?
Responses
A deletiondeletion
B insertioninsertion
C inversioninversion
D substitutionsubstitution
Question 2
PART B
When DNA replication occurs before meiosis, the original DNA strand GTC ACA GGC ATC is copied into complementary strand CAG CCG TAG. What type of mutation has occurred??
Responses
A deletiondeletion
B insertioninsertion
C inversioninversion
D translocationtranslocation
Answers
GPT-4o mini
**Question 1 - PART A:**
The original DNA strand is CAG TGT TTA TAG, and the complementary strand is GTC ACA GGC ATC.
To find the mutation type, we need to compare the original strand with the complementary strand:
- Original: CAG TGT TTA TAG
- Complementary (from the question): GTC ACA GGC ATC
If we align these:
CAG TGT TTA TAG
GTC ACA GGC ATC
If we analyze both strands, it seems there are several discrepancies between the two, which indicate that changes have occurred from the original to the new strand.
Particularly, there are specific differences:
- The original CAG was copied to GTC, indicating a substitution.
- The GTs and ACs also suggest variations and different arrangements compared to what would be expected.
Since the initial strand (CAG TGT TTA TAG) shows an alteration in bases in the copied strand, and if we observe it changes specific nucleotides, the mutation is a **D. substitution**.
---
**Question 2 - PART B:**
The original DNA strand is GTC ACA GGC ATC, and the complementary strand is CAG CCG TAG.
Aligning them:
- Original: GTC ACA GGC ATC
- Complementary (from the question): CAG CCG TAG
Comparing:
- The first three bases from the original GTC become CAG in the new strand.
- The middle basing changes occur, as ACA becomes CCG while GGC becomes just TAG (one base short), showcasing that some bases are missing.
From this analysis, we observe that not only are bases altered but also that entire sections of the original strand (like the last one or two bases) appear to be missing (or deleted).
This indicates that there was a **A. deletion** from the original strand to the complementary one.
**Final Answers:**
1. D. substitution
2. A. deletion
The original DNA strand is CAG TGT TTA TAG, and the complementary strand is GTC ACA GGC ATC.
To find the mutation type, we need to compare the original strand with the complementary strand:
- Original: CAG TGT TTA TAG
- Complementary (from the question): GTC ACA GGC ATC
If we align these:
CAG TGT TTA TAG
GTC ACA GGC ATC
If we analyze both strands, it seems there are several discrepancies between the two, which indicate that changes have occurred from the original to the new strand.
Particularly, there are specific differences:
- The original CAG was copied to GTC, indicating a substitution.
- The GTs and ACs also suggest variations and different arrangements compared to what would be expected.
Since the initial strand (CAG TGT TTA TAG) shows an alteration in bases in the copied strand, and if we observe it changes specific nucleotides, the mutation is a **D. substitution**.
---
**Question 2 - PART B:**
The original DNA strand is GTC ACA GGC ATC, and the complementary strand is CAG CCG TAG.
Aligning them:
- Original: GTC ACA GGC ATC
- Complementary (from the question): CAG CCG TAG
Comparing:
- The first three bases from the original GTC become CAG in the new strand.
- The middle basing changes occur, as ACA becomes CCG while GGC becomes just TAG (one base short), showcasing that some bases are missing.
From this analysis, we observe that not only are bases altered but also that entire sections of the original strand (like the last one or two bases) appear to be missing (or deleted).
This indicates that there was a **A. deletion** from the original strand to the complementary one.
**Final Answers:**
1. D. substitution
2. A. deletion