OCR A Biology
| Front | What is the relationship between a regulatory gene and a structural gene? |
| Back | The regulatory gene controls the expression of the structural gene |
| Front | Why and when is lactose broken down in bacteria? |
| Back | Normally, a bacterium would use glucose in aerobic respiration as a respiratory substrate, however, when glucose isn’t present and lactose is present, it would use lactose. -Proteins produced by the lac operon are only needed if glucose is absent and lactose is present In order to break down lactose, the bacteria needs to produce enzymes to hydrolyse the sugar. It also needs to produce proteins to transport the lactose into the bacteria. |
| Front | What are the two types of mutation? |
| Back | Gene mutations- these are changes to the base sequence in DNA Chromosomal mutations- these affect the whole chromosome or number of chromosomes within a cell |