 Substituting a balancer chromosome for the wild-type chromosome homologous to the chromosome carrying the  mutation prevents the establishment of wild-type organisms in various ways.
<clarity>  Substituting a balancer chromosome for the wild-type chromosome homologous to the chromosome carrying the  mutation prevents the establishment of wild-type organisms in various ways.
 Substituting a balancer chromosome for the wild-type homolog of the chromosome carrying the mutation prevents the establishment of wild-type organisms in various ways.