what is the lysosome

ATI TEAS 7

TEAS 7 science practice

1. What is a lysosome?

A. A sac-like structure that contains enzymes that break down cellular components
B. A network of tubules that transport proteins and lipids throughout the cell
C. The site of protein synthesis
D. The site of cellular respiration

Correct answer: A

Rationale: A lysosome is a membrane-bound organelle found in animal cells that contains digestive enzymes. These enzymes are responsible for breaking down various cellular components, such as proteins, lipids, carbohydrates, and even foreign particles like bacteria. This breakdown process is crucial for maintaining cell health and function by recycling and disposing of cellular waste. Options B, C, and D are incorrect because lysosomes are not involved in transporting proteins and lipids throughout the cell (option B), protein synthesis (option C), or cellular respiration (option D). Lysosomes primarily function as the cell's 'recycling center' by breaking down and processing cellular materials.

2. Which condition is characterized by inflammation of the inner lining of the stomach?

A. Gastroesophageal reflux disease (GERD)
B. Diverticulitis
C. Ulcerative colitis
D. Gastritis

Correct answer: D

Rationale: Gastritis is the correct answer as it is characterized by inflammation of the inner lining of the stomach. This inflammation can be caused by various factors such as excessive alcohol consumption, prolonged use of nonsteroidal anti-inflammatory drugs (NSAIDs), infections, or autoimmune diseases. Symptoms of gastritis may include abdominal pain, nausea, vomiting, and loss of appetite. Gastroesophageal reflux disease (GERD) is incorrect because it involves the backflow of stomach acid into the esophagus, leading to symptoms like heartburn and regurgitation, not inflammation of the stomach lining. Diverticulitis refers to inflammation or infection of small pouches that can form in the walls of the colon, not the stomach. Ulcerative colitis is a type of inflammatory bowel disease characterized by inflammation and ulcers in the colon and rectum, not the stomach lining.

3. What is the difference between a pure substance and a mixture?

A. Pure substances have a fixed composition, mixtures don't.
B. Mixtures have a fixed composition, pure substances don't.
C. Pure substances can be in any state, mixtures are not always solids.
D. Pure substances are always elements, mixtures are always compounds.

Correct answer: A

Rationale: Pure substances have a definite and constant composition, meaning they are made up of only one type of atom or molecule with fixed proportions. This composition does not vary. On the other hand, mixtures are composed of two or more substances physically combined. The components of a mixture can be present in varying proportions, leading to a variable composition. Choice A is correct as it accurately distinguishes between pure substances and mixtures based on the fixed composition of pure substances and the variable composition of mixtures. Choice B is incorrect because mixtures, not pure substances, have variable compositions. Choice C is incorrect as both pure substances and mixtures can exist in different states. Choice D is incorrect because pure substances can be compounds as well, not exclusively elements, and mixtures can contain elements and compounds.

4. Which of the following is the main organ responsible for producing bile?

A. Liver
B. Gallbladder
C. Pancreas
D. Stomach

Correct answer: A

Rationale: The liver is the main organ responsible for producing bile. Bile, a greenish-yellow fluid, is produced by the liver and stored in the gallbladder. Its primary function is to aid in the digestion and absorption of fats in the small intestine. When needed, the gallbladder releases bile into the small intestine to facilitate fat digestion. The pancreas produces digestive enzymes and insulin, not bile, making choice C incorrect. The stomach's primary role is to digest food through gastric juice secretion, making choice D incorrect. Therefore, the correct answer is the liver, as it is the main organ responsible for bile production.

5. What is the primary function of the respiratory system?

A. To digest food
B. To transport nutrients
C. To exchange gases
D. To regulate body temperature

Correct answer: C

Rationale: The correct answer is C: To exchange gases. The primary function of the respiratory system is to facilitate the exchange of gases, specifically oxygen and carbon dioxide, between the body and the environment. This process is essential for cellular respiration, where oxygen is taken in and carbon dioxide is removed. Choices A, B, and D are incorrect. Digesting food is primarily the function of the digestive system, transporting nutrients is the role of the circulatory system, and regulating body temperature is primarily managed by the integumentary system and the nervous system, not the respiratory system.