<span>The gene sequence containing an operator, promoter and repressor is known as an operon. These genes are called as structural genes. the operon is regulated by the presence/absence of the inducer such as glucose/lactose. It may also be a constitutive operon, which works all the time.</span>
C.<span>trees going dormant in winter to survive unfavorable conditions</span>
The correct answer is option b, that is, a polygenic trait that is affected by the number of alleles present.
There are three genes associated with a usual form of glaucoma, so it must be the polygenic trait, that is, it comprises more than one gene. The polygenic traits are affected by the number of alleles. In this circumstance, there are more than twenty genetic loci present, which signify that there must be a larger quantity of alleles for all the loci.