whales have similar structures to mammals for both their front limbs and even back legs. however a well uses its front limbs to swim while mammals like horses use their front limbs to walk based on our live class are theses homologous structures or analogous structures

Pls me i need this ! each cell has genes activated depending on it's job and what kind of cell it is. it is the presence of that causes the repressor protein to fall off and unblock the gene on the lac operon. if a gene is turned on then it is being an additional circular chromosome found in some bacteria that is used in genetic engineering.