quiz4

Which of the following is NOT true about the mechanism of miRNA?

• a) There is limited complementarity with the target, allowing for multiple possible targets
• b) It is an endogenous mechanism that is used by eukaryotes
• c) A hairpin structure is formed when pri-miRNA forms a complex with Argonaute protein
• d) Dicer degrades the pre-miRNA into small 21-25 base fragments
• e) It results in the prevention of translation of the target

Which one of the following statements regarding siRNA, miRNA and CRISPR technologies is NOT true:

• a) siRNA can be used to determine the phenotypic expression of a gene
• b) The ultimate goal of miRNA is to inhibit protein formation
• c) The PAM sequence taken from the bacteriophage and put into the Crispr array allows future recognition of the bacteriophage DNA
• d) Cas-9 would be able to bind to an invading bacteriophage DNA with the sequence:
• e) siRNA, miRNA and CRISPR-Cas9 are all able to cleave specific recognition sites

None

• 1
• 2
• 3
• 4
• 5

A group of scientists is studying a population of plants that display a wide range of leaf sizes. They have identified a gene, "Leafy1," which they believe influences leaf size. To test the function of "Leafy1," they plan to compare leaf sizes between normal plants and plants in which "Leafy1" has been disrupted. Given this scenario, choose the appropriate genetic approach and the expected observation to validate their hypothesis:

• Use forward genetics to induce mutations in "Leafy1" and look for plants with unchanged leaf sizes, suggesting "Leafy1" does not influence leaf size.
• Apply reverse genetics to disrupt "Leafy1" in some plants and observe if there is a significant difference in leaf sizes between the modified and normal plants, indicating "Leafy1" plays a role in determining leaf size.
• Employ forward genetics to cross plants with the largest leaves and observe if the "Leafy1" gene is present in the offspring with larger leaves, implying "Leafy1" is linked to leaf size.
• Implement reverse genetics to introduce additional copies of "Leafy1" into some plants and if leaf size decreases in these plants, it confirms "Leafy1" is negatively associated with leaf size.
• Utilize forward genetics to analyze "Leafy1" expression levels in plants exposed to varying soil nutrient conditions, expecting a straightforward relationship between nutrient availability and "Leafy1" activity affecting leaf size.

Which of the following statements does NOT reflect a characteristic of a switch regulatory pathway in the context of epistatic analysis?

• Constitutive mutation phenotypes
• An epistatic gene is downstream of the gene that it masks
• Gene products activate or inactivate each other
• Epistatic analysis requires mutations with distinct, but not opposite, phenotypes
• None of the above statements are correct; all statements are reflect the true characteristics of a switch regulatory pathway

which of the following examples represent expression of maternal effect mutation.

• fruit fly homozygous for bcd lays normal eggs but offsprings are headless
• fruit fly heterozygous for bcd lays normal eggs but offsprings are headless
• fruit flies homozygous for bcd are headless
• fruit flies heterozygous for bcd are headless
• none of the above

In a population of mice, fur colour is determined by two genes, A and B. Gene A controls the production of pigment, while gene B determines whether the pigment will be deposited in the fur or not. In this scenario, which of the following describes the epistatic relationship between gene A and gene B?

• A) Gene B is epistatic to gene A
• B) Gene A is epistatic to gene B
• C) Neither gene A nor gene B displays epistasis in this scenario
• D) Both genes A and B are epistatic to each other
• E) Not enough information was provided

What is the order of function in this switch regulation pathway?

• BCA
• ABC
• ACB
• CAB
• CBA

What would occur to CRISPR if there was a mutation in PAM?

• CRISPR would function normally and would be able to incorporate the phage DNA into their CRISPR array
• the acquisition step would be affected and the phage DNA would not be incorporated into the CRISPR array
• the acquisition step would occur normally but the immunity step would not
• the acquisition step would be affected but the phage DBA could still be incorporated into the CRISPR array
• Nothing, PAM is not involved in CRISPR