Types of Genetic Mutations and Their Effects

Nonsense

The substitution causes a stop codon to be produced, meaning that the protein is ended prematurely, and causing the protein to not work as intended, or at all. This can sometimes lead to genetic diseases.

Missense

The substitution causes a different amino acid to be coded for, meaning the protein produced might be unaffected, might not work at all, or may in rare cases work better.

Silent

The substitution has no effect, as it codes for the same amino acid.

Somatic mutations

Occur within body cells after conception, meaning they are not inherited and cannot be passed onto offspring.

Germline mutations

Occur within reproductive cells, and will affect all cells of the zygote. Is heritable and can be passed onto offspring.

Point mutations

When a single nucleotide base is altered, substituted, deleted or inserted.

Frameshift mutations

Types of point mutations, including addition, and deletion.

Germline mutations occur

before fertilisation and during early stages of zygote production

Stage 6 of natural selection

Over many generations, the frequency of the alleles for the favourable traits increases. The less favourable alleles will decrease in frequency.

Stage 1 of natural selection

There is variation in a population due to mutations and / or sexual reproduction.

Stage 2 of natural selection

There are more individuals produced in a population than the environment can support. Not all individuals can survive.

stage 3 of natural selection

Due to the limited resources, the selection pressures favour those with better suited / more advantageous characteristics. They out-compete those who do not possess the favourable traits.

stage 4 of natural selection

Those with the advantageous traits survive and reproduce. (survival of the fittest)

stage 5 of natural selection

When the survivors reproduce, they pass on their advantageous traits to offspring, as the traits are heritable.