Here is a complete HTML practice test with 10 true/false questions on cellular respiration, no answers shown, a final score, and a 1-minute timer that locks the quiz when time is up and then lets you reset it. ```html Cellular Respiration True/False Quiz

Cellular Respiration Practice Quiz

True / False (10 Questions)

Time remaining: 60 s

1. Cellular respiration is the process by which cells break down glucose to release usable energy in the form of ATP.

2. Glycolysis occurs in the mitochondria of eukaryotic cells.

3. The Krebs cycle (citric acid cycle) requires oxygen indirectly and takes place in the mitochondrial matrix.

4. During the electron transport chain, most of the ATP in aerobic respiration is produced.

5. Oxygen is the final electron acceptor in the electron transport chain of aerobic respiration.

6. Anaerobic respiration and fermentation allow cells to keep producing ATP when oxygen is not available.

7. A single molecule of glucose can yield a maximum of about 2 ATP molecules through aerobic respiration.

8. NADH and FADH₂ are high-energy electron carriers generated during cellular respiration.

9. Carbon dioxide is produced during both the Krebs cycle and the link (transition) reaction that converts pyruvate to acetyl-CoA.

10. In lactic acid fermentation, pyruvate is converted into ethanol and carbon dioxide in muscle cells.

``` This uses a 60-second countdown with `setInterval`, disables answer choices when time ends, automatically grades at 0 seconds, and then lets you press Reset to take the quiz again. [aamnah](https://aamnah.com/notes/javascript/countdown-timer-enable-button/) Do you want the timer to start automatically when the page loads instead of using the Start button?
Below is a complete HTML file with 100 true/false questions drawn from the GI diseases we discussed. It does NOT show which answers are correct, but it calculates a final score and lets you reset the test. Because of length, I organized questions in sections (esophagus, stomach, intestines, liver/pancreas, etc.) but kept everything in one page. You can copy–paste this into a `.html` file and open it in a browser. ```html GI Diseases True/False Practice Test (100 Questions)

Gastrointestinal Diseases True/False Test

100 Questions – No Answers Shown, Final Score Only

Esophagus & Upper GI

1. Gastroesophageal reflux disease (GERD) is caused by repeated backflow of stomach contents into the esophagus due to an incompetent lower esophageal sphincter.

2. Chronic GERD can lead to Barrett’s esophagus, in which the normal squamous epithelium of the distal esophagus is replaced by columnar intestinal-type epithelium.

3. In Barrett’s esophagus, the risk of esophageal adenocarcinoma is lower than in the general population.

4. Hiatal hernia occurs when a portion of the stomach herniates through the diaphragmatic hiatus into the chest cavity.

5. Achalasia is characterized by failure of the lower esophageal sphincter to relax and loss of normal esophageal peristalsis.

6. Progressive difficulty swallowing both solids and liquids is a typical symptom of achalasia.

7. Esophageal varices are dilated veins in the distal esophagus mainly caused by systemic hypertension rather than portal hypertension.

8. Massive upper gastrointestinal bleeding with hematemesis can result from rupture of esophageal varices.

9. Esophageal cancer commonly presents with progressive dysphagia and unintentional weight loss.

10. Adenocarcinoma of the esophagus is strongly associated with long-standing GERD and Barrett’s esophagus.

Stomach & Duodenum

11. Gastritis refers to inflammation of the stomach lining and may be acute or chronic.

12. Long-term NSAID use and Helicobacter pylori infection are important causes of gastritis.

13. Peptic ulcer disease includes both gastric and duodenal ulcers caused by acid-induced damage of the mucosa.

14. Duodenal ulcers are most commonly associated with malignancy and always require surgical resection.

15. Gastric ulcers often need endoscopy and biopsy to exclude underlying gastric cancer.

16. Viral gastroenteritis typically causes acute nausea, vomiting, and watery diarrhea over a few days.

17. Dehydration is the main serious complication of acute gastroenteritis, especially in infants and older adults.

18. Gastric intestinal metaplasia is a benign finding that carries no increased risk of gastric cancer.

19. Chronic H. pylori infection can lead to gastric atrophy, intestinal metaplasia, and increased risk of stomach cancer.

20. Gastric adenocarcinoma commonly presents early with dramatic, specific symptoms, making early detection easy.

Small Intestine, Malabsorption & Infections

21. Celiac disease is an autoimmune disorder in which gluten ingestion damages the small intestinal villi.

22. People with celiac disease must follow a strict lifelong gluten-free diet to prevent complications.

23. Lactose intolerance is usually caused by an immune reaction to lactose that destroys intestinal villi.

24. Bloating and diarrhea after consuming milk products are common symptoms of lactose intolerance.

25. Small intestinal bacterial overgrowth (SIBO) involves an abnormally high number of bacteria in the small intestine, leading to gas and malabsorption.

26. Conditions that slow intestinal motility or alter anatomy can predispose to SIBO.

27. Ascariasis is a viral infection of the intestine acquired through inhalation of airborne spores.

28. Heavy Ascaris lumbricoides infections can cause intestinal obstruction and biliary or pancreatic complications.

29. Intussusception occurs when one segment of intestine telescopes into another, often leading to obstruction.

30. Volvulus refers to twisting of the intestine around its mesentery, which can compromise blood supply and cause ischemia.

Colon & Inflammatory Bowel Disease

31. Ulcerative colitis affects the colon and rectum with continuous superficial inflammation of the mucosa.

32. Crohn’s disease can affect any part of the GI tract and typically involves transmural, patchy (“skip”) lesions.

33. Chronic ulcerative colitis and Crohn’s colitis both increase the risk of colorectal cancer over time.

34. Microscopic colitis (collagenous or lymphocytic) typically causes chronic watery diarrhea with a normal-appearing colon on endoscopy.

35. Collagenous colitis is defined by a thickened subepithelial collagen band in colonic biopsies.

36. Irritable bowel syndrome (IBS) is a structural disease of the colon characterized by ulcers and bleeding.

37. IBS is a functional disorder characterized by abdominal pain associated with changes in bowel habits, without detectable structural damage.

38. Diverticulosis refers to the presence of multiple outpouchings of the colonic wall, often in the sigmoid colon.

39. Diverticulitis describes inflammation and infection of diverticula, often presenting with left lower quadrant pain and fever.

40. Colon polyps are always malignant and should be left in place to avoid bleeding during removal.

Colorectal Neoplasia & Syndromes

41. Adenomatous colon polyps can be precursors to colorectal cancer if left untreated.

42. Colorectal cancer often develops through an adenoma–carcinoma sequence over several years.

43. Lynch syndrome is a hereditary colorectal cancer syndrome caused by germline mutations in mismatch-repair genes.

44. Patients with Lynch syndrome have increased risks of colon, endometrial, and certain other cancers at younger ages.

45. Familial adenomatous polyposis (FAP) is characterized by hundreds to thousands of colorectal polyps and a very high risk of colorectal cancer.

46. Prophylactic colectomy is often recommended in classic FAP to prevent cancer.

47. Meckel’s diverticulum is a true congenital diverticulum of the small intestine that may contain ectopic gastric mucosa.

48. Meckel’s diverticulum always causes severe symptoms in early childhood and never remains asymptomatic.

49. Gastrointestinal stromal tumors (GISTs) are mesenchymal tumors often driven by KIT or PDGFRA mutations.

50. Tyrosine kinase inhibitors such as imatinib have no role in the management of GISTs.

Liver & Biliary – Hepatitis, Cirrhosis, Tumors

51. Hepatitis refers to inflammation of the liver, which can be caused by viruses, alcohol, drugs, autoimmune disease, or metabolic disorders.

52. Chronic hepatitis B and C infections can progress to cirrhosis and hepatocellular carcinoma.

53. Cirrhosis is characterized by diffuse hepatic fibrosis and regenerative nodules, which distort normal liver architecture.

54. Portal hypertension, ascites, and variceal bleeding are common complications of advanced cirrhosis.

55. Non-alcoholic fatty liver disease (NAFLD) is closely associated with obesity, insulin resistance, and metabolic syndrome.

56. Non-alcoholic steatohepatitis (NASH) is a severe form of NAFLD that can progress to cirrhosis and HCC.

57. Hepatocellular carcinoma most commonly arises in a normal liver with no underlying chronic disease.

58. Surveillance for HCC in cirrhosis often uses liver ultrasound with or without alpha-fetoprotein measurement.

59. Gallstones are hardened deposits that form mainly in the gallbladder from components of bile, such as cholesterol or pigment.

60. Biliary colic describes episodic right upper quadrant pain caused by transient obstruction of the cystic duct by gallstones.

Pancreas & Biliary Complications

61. Acute pancreatitis is an inflammatory condition in which pancreatic enzymes autodigest the pancreas.

62. Gallstones and chronic heavy alcohol use are the two most common causes of acute pancreatitis.

63. Chronic pancreatitis can lead to exocrine insufficiency, malabsorption, and diabetes due to destruction of pancreatic tissue.

64. Pancreatic ductal adenocarcinoma is typically detected early and has an excellent overall prognosis.

65. New-onset diabetes and painless jaundice in an older adult can be warning signs of pancreatic cancer.

Functional & Motility Disorders

66. Functional dyspepsia is defined by chronic upper abdominal symptoms without structural disease on standard testing.

67. In functional dyspepsia, endoscopy typically reveals multiple ulcers and obvious inflammation.

68. Constipation is commonly defined clinically as fewer than three spontaneous bowel movements per week or difficult stool passage.

69. Low-fiber diet, certain medications, and lack of physical activity can all contribute to chronic constipation.

70. Acute diarrhea is typically defined as watery stools lasting longer than six months.

Anorectal Disorders

71. Hemorrhoids are swollen vascular cushions in the anal canal that can cause bleeding, pain, or prolapse.

72. External hemorrhoids are typically painless, whereas internal hemorrhoids are usually very painful.

73. Anal fissures cause sharp pain during bowel movements and bright red rectal bleeding on toilet paper.

74. Perianal abscesses arise from infection of anal glands and may evolve into chronic anal fistulas.

75. Anal fistulas are abnormal connections between the anal canal and perianal skin that typically require surgical management.

Obstruction & Emergencies

76. Intestinal obstruction prevents normal passage of intestinal contents and can be caused by adhesions, hernias, tumors, or strictures.

77. Severe intestinal obstruction can lead to bowel ischemia, perforation, and peritonitis if untreated.

78. Volvulus and intussusception both involve forms of intestinal obstruction that may compromise blood supply.

79. Hirschsprung’s disease is a congenital condition in which segments of colon lack ganglion cells, causing functional obstruction.

80. Intestinal pseudo-obstruction is a mechanical blockage caused by a tumor in the colon.

Miscellaneous GI Conditions

81. Gastroesophageal reflux disease can worsen chronic cough and asthma symptoms by irritating the airways.

82. Irritable bowel syndrome is commonly divided into constipation-predominant, diarrhea-predominant, and mixed subtypes.

83. GERD, hiatal hernia, and obesity often coexist and can exacerbate one another’s symptoms.

84. Gastroenteritis caused by viruses usually requires long-term antibiotic therapy to resolve.

85. Ascites in cirrhosis is managed with sodium restriction, diuretics, and sometimes large-volume paracentesis.

86. Esophageal variceal bleeding is considered a minor complication of portal hypertension with low mortality.

87. Gallstones may be completely asymptomatic or cause biliary colic, cholecystitis, or pancreatitis.

88. Chronic heavy alcohol use increases the risk of both pancreatitis and cirrhosis.

89. Most cases of colorectal cancer occur in individuals with well-known hereditary syndromes like FAP and Lynch syndrome.

90. Early detection of colorectal cancer through screening significantly improves survival rates.

91. Celiac disease is strongly associated with HLA-DQ2 and HLA-DQ8 genetic types.

92. Functional dyspepsia and IBS can overlap and are both disorders of gut–brain interaction.

93. Hirschsprung’s disease usually presents with chronic diarrhea in infants who pass meconium early.

94. Intestinal pseudo-obstruction is a motility disorder that mimics mechanical obstruction without an actual physical blockage.

95. Anal fissures commonly occur in the posterior midline and can become chronic if not treated.

96. Perianal fistulas never occur in Crohn’s disease.

97. Microscopic colitis is often associated with chronic watery diarrhea in older adults.

98. Non-steroidal anti-inflammatory drugs (NSAIDs) can contribute to both gastritis and peptic ulcer disease.

99. Viral hepatitis A typically causes chronic infection leading to cirrhosis in most patients.

100. Hepatitis B and C viruses can be transmitted through blood and body fluids and may be prevented or treated with specific therapies.

``` This follows the same pattern as standard JS quiz examples (radio buttons, answer key, score calculation, reset function) but hides which options are correct and only shows the overall score. [stackoverflow](https://stackoverflow.com/questions/28403558/multiple-choice-quiz-getting-score) Do you also want a timed version of this 100-question test (for example, 20 or 30 minutes with auto-lock and score at time up)?