Biology Questions and Answers
(placement of additional nucleotides in
the DNA molecule).
- Does every gene mutation
cause alteration in the protein
the gene normally codifies?
Not every gene mutation causes
alteration protein the gene codifies. Since tin the composition of thehe (^)
genetic code is degenerated, i.e., there
are amino one different DNA nacids codified by more thanucleotide triplet, if
by chancor more nucleotide the mutation sues of a codifier triplbstitutes oneet
and the newly formed triplet still
codifies ththe original triple same amiet there will beno acid co nodified by
modification in the protein made from
the gene.
- How do genetic mutations
influence biological diversity?
Too extensive mutations generally aror too frequent genetice deleterious for (^)
individuals and species. These
mutationsphenotypical chan often cause imges or defectsportant
incompatible with the survival of the
body and the continuity of the species.
However small genetic mutations that
do not cause tchanges are continuously accumulatedhe appearing of lethal (^)
in the genetic patrimony of the species.
These mutations gother giving birth to smallradually a phenotypicaldd to each (^)
changes in individuals. Tchanges are exposed to the hese smallselective (^)
criticism of the environment (natural
selection) and the more favorable for
survival and reproduction are preserved
(the remaider are carriers have difficulty in eliminatesurviving d as theirand (^)
reproducing). In this manner the
combined processes osmall mutations and of natural selectionf accumulation of (^)
incorporate new features in the species
and they may e(formation of new species) aven lead to speciationnd
promotion of biological diversity.
(Obviously only genetic mutationstransmitted by cells that originate n (^) ew
individuals, in reproduction, have evolutionary esexual or asexual (^) ffect.)
- What are mutagenic
agents?
Mutagenic agents, or mutagens, are
physical,that can chemical or biological factorscause alteration in DNA
molecules.
Examples obe mutagenic agents are: X, alpha, f well-known or believed tobeta (^)
and gamma rays, ultraviolet ranitrous acid, many dyes, some diation,
sweeteners, some herbicides, many
substanceslike HPV, etc. Small of tobacco, DNA fra some viruses,gments
known as transposons can also act as
mutagens when incorporateDNA molecules. d into other
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