Question

The zebra fish mutation that reduced coloration created a null allele of the transport protein gene. Which of the following types of mutation would be most likely to create this null allele? a. a missense mutation b. a frameshift mutation c. a neutral mutation d. a silent mutation

Short answer

A frameshift mutation is the most likely type of mutation to create a null allele of the transport protein gene, resulting in reduced coloration in zebrafish. Therefore, the correct answer is b. a frameshift mutation.

Step-by-step solution

Understand the Types of Mutations

To solve this problem, first, you need to know what each type of mutation is: a. Missense Mutation: A type of mutation that replaces one amino acid with another within a protein, potentially altering its function. b. Frameshift Mutation: A type of mutation caused by an insertion or deletion of a number of nucleotides that is not divisible by three from a DNA sequence, which shifts the reading frame and leads to the production of a different protein or a nonfunctional protein. c. Neutral Mutation: A type of mutation that has no effect on the function or fitness of an organism, usually because it occurs in a non-coding region of the DNA or does not affect the protein function. d. Silent Mutation: A type of mutation that changes a codon (a sequence of three nucleotides in DNA or RNA) to another codon that still codes for the same amino acid, thus having no effect on the resulting protein.

Identify the Mutation Leading to a Null Allele

To find out which mutation is most likely to create a null allele of the transport protein gene, we should look for the type of mutation that can result in a nonfunctional protein. a. A missense mutation has the potential to alter the function of a protein, but it doesn't guarantee that it will always lead to a nonfunctional protein. Therefore, a missense mutation might or might not create a null allele. b. A frameshift mutation often leads to the production of a different or nonfunctional protein. Since null alleles result in nonfunctional or missing protein products, a frameshift mutation is highly likely to cause a null allele. c. A neutral mutation doesn't affect the function or fitness of an organism, so it's not likely to create a null allele. d. A silent mutation doesn't affect the resulting protein, so it's not likely to create a null allele.

Choose the Most Likely Type of Mutation

Based on our understanding of each type of mutation, we can conclude that a frameshift mutation is the most likely mutation to create a null allele that results in reduced coloration in zebrafish. So, the correct answer is: b. a frameshift mutation

Key concepts

null allele

A null allele is a genetic term used to describe a version of a gene that completely lacks the normal function associated with that gene. This often results from mutations that lead to the gene product being nonfunctional or not produced at all. When an organism carries a null allele, it means that the impact of that gene on the organism is nullified, hence the name.

• Null alleles can arise from a variety of genetic alterations.
• These changes often result in severe effects on the organism due to the lack of a functional gene product.
• In many cases, null alleles are identified when specific phenotypes linked to the gene function, like coloration in zebrafish, are noticeably absent or altered.

Understanding null alleles is essential in genetic studies, as they provide insights into gene function and help elucidate the biological processes they control.

frameshift mutation

A frameshift mutation is a type of genetic mutation resulting from insertions or deletions of nucleotides in the DNA sequence that are not in multiples of three. Because the genetic code is read in triplets, a frameshift alters the grouping of the codons, leading to a significantly different translation from the original.

• Frameshift mutations often result in severe consequences for the resulting protein's structure and function.
• The alteration generally leads to a completely different amino acid sequence downstream from the mutation site.
• This can generate a nonfunctional protein, potentially creating a null allele.

Due to their drastic effects, frameshift mutations are integral in understanding how specific genetic alterations can disrupt normal biological processes.

zebra fish

Zebra fish are small freshwater fish that are widely used in biological research due to their genetic similarity to humans and their transparent embryos, which allow easy observation of developmental processes.

• Their fast reproduction rates and easily observable phenotypes make them ideal for genetic experiments.
• Zebrafish are often used to study diseases, gene functions, and mutations.
• Mutations affecting certain genes in zebrafish can lead to noticeable phenotypic changes, such as altered coloration. This serves as a great model for studying genetic pathways and gene function in vivo.

With their robust genetic foundation and practical research applications, zebrafish are indispensable in advancing our understanding of genetics and developmental biology.