Earth has seasons because a. it rotates on its axis. b. the distance between earth and the sun changes. c. its axis is tilted as it moves around the sun. d. the temperature of the sun changes. select the best answer from the choices provided a b c d

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.