| A | B |
|---|
| operan | consists of three segments. |
| promoter, operator, structural genes | segments of an operan |
| lac operan | causes the expression of the polypeptides that aid in the control of lactose in prokaryotes. |
| repressor | a molecule that inhibits a gene from being expressed. |
| regulator gene | codes for the repressor. |
| inducer | a molecule that iniates gene expression. |
| nucleosomes | DNA arapped around histone complexes. |
| heterochromatin | tightly coiled nucleosomes |
| euchromatin | uncoiled DNA |
| enhancer | must be activated for the gene in euchromatin to be expressed |
| introns | do not code for proteins |
| Exons | function as codons during protein synthesis. |
| blastula | the beginning of a baby |
| cell differentiation | the change in morphology or physiology of a cell |
| gastrula | a blastula that has formed a pocket |
| homeotic genes | genes that control the development of specific adult structures |
| imaginal disks | become prominent in the pupa stage. |
| sarcomas | gro in the bone and muscle. |
| lymphoma | solid tumors that grow in the tissues that form blood cells. |
| leukemia | the uncontrolled production of immature white blood cells |
| benign tumors | pose no threat |
| malignant tumors | called cancer |
| malignant tumors | break away and cause new tumors. |
| carcinomas | grow in the skin and nerves |
| lymphomas | solid tumors that grow in tissue that form blood cells. |
| leukemia | abnormal growth of immature white blood cells. |
| carcinogen | any substance that causes cancer. |
| oncogene | causes a normal cell to become cancerous. |
