When is gene expression blocked in the lac operon system? RNA polymerase begins transcribing the genes.

The repressor protein blocks the genes from making mRNA.

The repressor protein destroys the genes required to produce enzymes.

Lactose binds to the repressor and changes its shape.

any abiotic or biotic factor in an ecosystem that causes a population's size to slow or decrease is a limiting factor.

emerging idea only occurs as a raw idea that could appear out of nowhere. meanwhile, to reach scientific consensus , that idea must be structured and tested over and over again through various experiments. the scientific consensus transforms the raw idea into idea that is more reliable through the process of scientific elimination.

genetic variation will increase because of a new habitat and food source.

explanation:

c. heat from the poles back down towards the equator.