- Spontaneity of mutation means
(1) Mutation in absence of exogenous mutagen
(2) Mutation directly proportion to presence of mutagen
(3) Mutation inversely proportion to presence of mutagen
(4) Mutation at in appropriate time11. Spontaneity of mutation means (1) Mutation in absence of exogenous mutagen (2) Mutation directly proportion to presence of mutagen (3) Mutation inversely proportion to presence of mutagen (4) Mutation at in appropriate time solve this question in details explain every option and write SEO friendly article on it with key phrase and metadiscriprion and slug, slug shoud be from keywords of question. and the keyswords of slug and discription and keyphrase and introduction should be according to SEO and give also title nameSpontaneity of mutation refers to genetic changes occurring naturally without external mutagens, primarily due to errors in DNA replication or cellular processes. This concept is crucial for CSIR NET Life Sciences aspirants studying mutation types. The correct answer to the MCQ is option (1).
Option Analysis
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(1) Mutation in absence of exogenous mutagen: Correct. Spontaneous mutations arise naturally from replication errors, tautomerism, or depurination without any external agents like chemicals or radiation.
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(2) Mutation directly proportion to presence of mutagen: Incorrect. This describes induced mutations, where mutation frequency increases with mutagen exposure, such as UV light or chemicals.
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(3) Mutation inversely proportion to presence of mutagen: Incorrect. No biological basis exists; mutations do not decrease with more mutagen presence.
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(4) Mutation at in appropriate time: Incorrect. This vague phrasing lacks scientific meaning and does not define spontaneity.
Key Mechanisms
Spontaneous mutations occur at low rates (10^{-9} to 10^{-10} per nucleotide per generation) due to slipped strand mispairing, wobble base pairing, or transposon activity. These differ from induced mutations caused by deliberate mutagen application in labs. Examples include sickle cell anemia arising naturally.
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