1.
Damage and errors in DNA cause___________
Correct Answer
A. Mutation
Explanation
Damage and errors in DNA can lead to changes in the genetic information, resulting in a mutation. Mutations can occur due to various factors such as exposure to harmful substances, errors during DNA replication, or environmental factors. These mutations can have different effects, ranging from no impact to significant changes in the organism's traits or functions. Thus, damage and errors in DNA can cause mutations, altering the genetic makeup of an organism.
2.
All types of mutations are transferable among generations.
Correct Answer
B. False
Explanation
Mutations are changes in the DNA sequence that can occur randomly or due to environmental factors. While mutations can be inherited and passed on to future generations, not all mutations are transferable. Some mutations may occur in somatic cells and only affect the individual in which they occur, while others may occur in germ cells and be passed on to offspring. Therefore, it is incorrect to say that all types of mutations are transferable among generations.
3.
Mark the INCORRECT statement about mutation.
Correct Answer
A. Mutation is predestined
Explanation
The statement "Mutation is predestined" is incorrect. Mutations are random and spontaneous changes in the DNA sequence and are not predetermined or predestined. They can occur due to various factors such as errors during DNA replication or exposure to mutagens. Mutations can have different effects on an organism, and they can be beneficial, neutral, or deleterious. Therefore, the statement that mutations are predestined is incorrect.
4.
Which of the following is NOT a type of reverse mutation?
Correct Answer
D. Missense mutation
Explanation
A missense mutation is a type of point mutation where a single nucleotide change results in a different amino acid being incorporated into the protein sequence. It is not a type of reverse mutation because it does not revert the mutated gene back to its original form. In contrast, back mutation, intergenic suppressor mutation, and intragenic suppressor mutation are all types of reverse mutations where the mutated gene reverts back to its original form.
5.
Which of the following is NOT true for loss of function mutation?
Correct Answer
C. Increases the activity of the gene
Explanation
Loss of function mutations typically result in a decrease or complete loss of the activity of a gene. This means that the gene is not functioning properly or not producing the expected protein. Therefore, it is not true that loss of function mutations increase the activity of the gene.
6.
Name the term given to the type of mutation which depends on the conditions of the environment.
Correct Answer
C. Conditional lethal mutation
Explanation
A conditional lethal mutation refers to a type of mutation that only causes cell death under specific conditions in the environment. This means that the mutation is not lethal in all conditions, but instead, it depends on certain factors such as temperature, pH, or the presence of certain substances. The mutation may disrupt essential cellular processes or functions, leading to cell death only when the specific conditions required for its lethality are met.
7.
What is the detection technique of auxotrophs?
Correct Answer
B. Replica plating
Explanation
Replica plating is a detection technique used for auxotrophs. It involves making an imprint of bacterial colonies onto a replica plate containing a different medium. This allows for the identification of auxotrophs, which are mutant strains that require specific nutrients not needed by wild-type strains. By comparing the growth patterns on the replica plate to the original plate, auxotrophs can be detected based on their inability to grow on the medium lacking the required nutrients.
8.
Name the type of mutation in which the cause of mutation is not known.
Correct Answer
A. Spontaneous mutation
Explanation
Spontaneous mutation refers to a type of mutation where the cause is not known. It occurs naturally without any external factors or exposure to mutagens. These mutations can arise from errors during DNA replication or from spontaneous changes in the DNA structure. Since the cause is unknown, it is difficult to pinpoint the exact reason behind the occurrence of these mutations.
9.
Addition or deletion of bases causes which kind of mutation?
Correct Answer
B. Frameshift mutation
Explanation
Frameshift mutation occurs when bases are added or deleted in the DNA sequence, causing a shift in the reading frame during translation. This mutation can have significant effects on the resulting protein, as it alters the entire sequence of amino acids downstream of the mutation. It can lead to a nonfunctional or completely different protein being produced, which can have detrimental effects on the organism. Therefore, frameshift mutation is the correct answer for the given question.
10.
Which of the following chemical mutagen affects only replicating DNA?
Correct Answer
D. Base analog
Explanation
Base analogs are chemical mutagens that resemble the nucleotide bases found in DNA. They can be incorporated into the DNA during replication, leading to the introduction of mutations. Since base analogs specifically affect replicating DNA, they do not have a significant impact on non-replicating DNA. This makes base analogs a unique type of chemical mutagen that selectively targets replicating DNA.