Female twins who grew up in the same household go off to college. After four years, one of them develops schizophrenia, the other stays mentally healthy. What phenomenon can explain this development?

In mature mRNA, exons have been spliced out and introns will be translated into protein

Would transcription occur in lac operon, if lactose is absent and the mutation in the repressor is lacI-?

Imagine you have the following operon that includes the genes that encode enzymes A, B, and C, which are required for the biosynthesis of molecule X into Y in most bacteria.  The product of gene M regulates gene expression in this cell. When there is a high level of the M product, you do not detect any levels of A, B, and C enzymes but when there is a low level of the M product you detect higher levels of the enzymes. Thus, the product of the M gene is a:

Which of the following statements is/are true? Select all that apply.

Which process best explains the reason we have ~100,000 proteins, but only ~20,000 protein-encoding genes?

How are epigenetic changes and mutations different?

The TATA box can only be found in bacteria.

What is epigenetics?

Imagine you have the following operon that includes the genes that encode enzymes A, B, and C, which are required for the biosynthesis of molecule X into Y in most bacteria.  The product of gene M regulates gene expression in this cell. When there is a high level of the M product, you do not detect any levels of A, B, and C enzymes but when there is a low level of the M product you detect higher levels of the enzymes. Thus, the product of the M gene is a: