What is the original source of energy for most ecosystems? A grass
B) humans
C)the sun
D)heat

If t=tall and t=short what will be the physical appearance of the offspring the cross below? a.some will be tall and some will be short b.they will all be tall c.they will all be short d.they will be medium height

Which of the following statements is true of cells

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.