Which of the following statements correctly distinguishes between the cellular characteristics and behavior of benign and malignant tumors?
Benign tumor cells down-regulate cell-adhesion molecules to remain anchored within a single tissue, whereas malignant tumor cells up-regulate these molecules to migrate and adhere to new organs during metastasis.
Benign tumors are typically encapsulated by a boundary of connective tissue and do not invade surrounding tissues, whereas malignant cells can secrete enzymes that degrade the extracellular matrix, enabling them to enter blood or lymph vessels.
Benign tumors consist of poorly differentiated, specialized cells that have lost all homeostatic control, whereas malignant tumors consist of highly differentiated cells that retain their tissue-specific structures.
Benign tumors actively secrete angiogenic factors to establish a localized blood supply for rapid systemic invasion, whereas malignant tumors lack a blood supply and survive solely through anaerobic respiration.
97 exam-style questions on OCR GCSE Biology 6.3 Monitoring and maintaining health, covering 6.3.1 Health and disease, 6.3.2 Interactions between diseases, 6.3.3 Spread of communicable diseases, 6.3.4 Common infections and diseases, 6.3.5 Physical plant defence responses, 6.3.6 Chemical plant defence responses, 6.3.7 Detecting and identifying plant diseases, 6.3.8 White blood cells and platelets, 6.3.9 Non-specific defence systems, 6.3.10 The immune system, 6.3.11 Monoclonal antibodies, 6.3.12 Vaccines and medicines, 6.3.13 Aseptic techniques, 6.3.14 Discovery and development of new medicines, 6.3.15 Causes of non-communicable diseases, 6.3.16 Treatments for cardiovascular disease, 6.3.17 Lifestyle factors and non-communicable diseases, 6.3.18 Cancer, 6.3.19 Stem cells in medicine, 6.3.20 Gene technology in medicine, and 6.3.21 The human genome and medicine. Each one has a worked solution and a mark scheme showing where the marks go.