4.3.10

Mutations

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Mutations

Mutations are random and permanent changes to the base sequence of existing genes. Mutations create new alleles.

Illustrative background for What rate do mutations happen at?Illustrative background for What rate do mutations happen at? ?? "content

What rate do mutations happen at?

  • Mutations are rare.
  • The rate of mutations can be increased by ionising radiation and some chemical mutagens (mutation-causing chemicals).
    • Gamma rays, x-rays and ultraviolet rays are types of ionising radiation.
    • Several chemicals in tobacco are mutagens.
Illustrative background for Do mutations always affect the phenotype?Illustrative background for Do mutations always affect the phenotype? ?? "content

Do mutations always affect the phenotype?

  • Most mutations do not affect the phenotype.
  • Mutations that do affect phenotype can have positive or negative effects.

Jump to other topics

1The Nature & Variety of Living Organisms

2Structure & Functions in Living Organisms

3Organism Functions

3.1Respiration

3.2Gas Exchange

3.3Transport

3.4Excretion

3.5Coordination & Response

4Reproduction & Inheritance

5Ecology

6Biological Resources

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