What is the meaning of endocytosis?
- A. The cell engulfs solid particles.
- B. The cell engulfs liquid material.
- C. The cell expels solid particles.
- D. The cell releases liquid material.
Correct Answer: A
Rationale: Endocytosis is a cellular process where the cell engulfs and internalizes solid particles by forming vesicles. It is a mechanism used for nutrient uptake, cell signaling, and maintaining cellular homeostasis. Options B, C, and D describe processes that are opposite to endocytosis. Choice B is incorrect because it describes pinocytosis, which is the process of engulfing liquid material. Choice C is incorrect as it describes exocytosis, the process of expelling material from the cell. Choice D is incorrect as it describes the process of releasing liquid material from the cell. Therefore, the correct answer is A.
You may also like to solve these questions
When the pulmonary valve and aortic valves are open, where can blood flow?
- A. Between the two ventricles of the heart
- B. From atrium to ventricle within the heart
- C. Between the heart and the rest of the body
- D. Between the atria in the heart
Correct Answer: C
Rationale: When the pulmonary valve and aortic valves are open, blood can flow between the heart and the rest of the body. The pulmonary valve allows blood to flow from the right ventricle to the lungs for oxygenation, while the aortic valve permits blood to flow from the left ventricle to the rest of the body for distribution of oxygen and nutrients. This circulation pathway ensures that oxygen-rich blood is pumped to the body tissues. Choices A, B, and D are incorrect because when the pulmonary valve and aortic valves are open, blood is not flowing between the ventricles, from atrium to ventricle, or between the atria; instead, it is being pumped out of the heart to the lungs and the rest of the body.
A tissue examined under the microscope exhibits the following characteristics: cells found on the internal surface of the stomach, no extracellular matrix, cells tall and thin, no blood vessels in the tissue. What type of tissue is this?
- A. Epithelial
- B. Connective tissue
- C. Cartilage
- D. Nervous
Correct Answer: A
Rationale: The correct answer is 'Epithelial.' Epithelial tissue is characterized by cells lining surfaces and cavities, such as the stomach. It does not contain blood vessels, and the cells are tall and thin. The absence of an extracellular matrix is typical of epithelial tissue, making it the most suitable choice in this scenario. Connective tissue, like cartilage and nervous tissue, have different characteristics that do not align with the description provided in the question.
The orthopedic surgeon informs you that you have broken the middle region of the humerus. What area is he describing?
- A. Epiphysis
- B. Articular cartilage
- C. Perichondrium
- D. Diaphysis
Correct Answer: D
Rationale: The diaphysis is the correct answer in this scenario. It refers to the middle or shaft region of a long bone like the humerus. The epiphysis is the end of a long bone, while articular cartilage is the smooth tissue covering the ends of bones at a joint. The perichondrium is the dense irregular connective tissue that surrounds cartilage.
How many bones are found in the human skull?
- A. Approximately 5
- B. Approximately 30
- C. Approximately 60
- D. Approximately 210
Correct Answer: B
Rationale: The correct answer is B: Approximately 30. The human skull is composed of 22 bones that are fused together. These 22 bones consist of 8 cranial bones and 14 facial bones, totaling approximately 30 bones in total. Choices A, C, and D are incorrect because the human skull does not have as few as 5 bones, as many as 60 bones, or as many as 210 bones. Understanding the basic anatomy of the skull helps in identifying the correct number of bones it comprises.
Which of the following structures has the lowest blood pressure?
- A. arteries
- B. arterioles
- C. venules
- D. veins
Correct Answer: D
Rationale: Veins have the lowest blood pressure among the listed structures. This is because veins carry blood back to the heart at a slower rate compared to arteries, arterioles, and venules. The lower blood pressure in veins allows for the efficient return of blood to the heart despite the decreased pressure. Arteries have high blood pressure as they transport blood away from the heart at a rapid rate. Arterioles are smaller branches of arteries and contribute to resistance in the circulatory system, leading to a pressure drop. Venules are small blood vessels that collect blood from capillaries and gradually converge into veins, having slightly higher pressure than veins.