Genetic diversity and adaptations

When a base in a sequence of amino acid is changed.

When a base is removed from a sequence of amino acids this changes the sequence and results in the sequence being read differently.

DNA replication - chromosomes and chromatids Homologous chromosomes line up in pairs randomly (independent segregation) Division 1- homologous pairs separate Division 2- chromosomes and copies split Gametes formed (haploid)

Any change to one or more nucleotide bases, or a change in the sequence of the bases in DNA

This can result in different amino acids however doesn’t often lead to a mutation as multiple codons code for the same amino acid and might occur in an intron which is non-coding and will be removed during splicing.

This will lead to a mutation as the exons will be changed as well as the introns changing the structure of the protein. - polypeptide will be entirely different and might not function correctly

-changes in whole sets of chromosomes -changes in the number of individual chromosomes

sometimes individual homologous pairs of chromosomes fail to separate during meiosis, this is known as non-disjunction.

results in gametes having either one more or one fewer chromosomes

-independent segregation -crossing over

homologous pairs line up randomly

-Chromatids of each pair become twisted around each other -chromatids break off due to tension -might re-join with the chromatid of its homologous pair

The number of different alleles of genes in a population

The process that leads to evolution in population

• New alleles for a gene are created by random mutations • If the new alleles increases the chances of survival in that environment then they are more likely to survive and reproduce 3.This reproduction passes on the advantageous allele to the next generation. • As a result over many generations the new allele increases in frequency in the population

A group of individuals of the same species that live in the same place and can interbreed

The total number of alleles in a particular population at a specific time

The process in which organisms that are better adapted to their environment tend to survive and breed

Occurs when the environmental conditions change and the phenotypes best suited to the new conditions are more likely to survive. As a result these individuals will breed and produce offspring.

Bacteria being resistant to antibiotics. -single bacteria has a mutation meaning it is not killed as it produces the enzyme penicillinase . -As a result it can grow and populate and the frequency of alleles that enabled penicillinase production increased in population -Therefore the population moved to have greater penicillin resistance

The phenotypes with successful characteristics are preserved and those of greater diversity are reduced. This selection doesn’t occur due to changes in the environment. If the environment stays the same then the individuals closest to the mean are favoured

New born babies weights. Those that have birth weights of around 3kg are more likely to survive than those at the extremes