Concept explainers
More than one choice may apply.
Which of the following would you expect to find associated with cells producing hormones or neu-rotransmitters?
a. Cilia c. Gap junctions
b. Secretory vesicles d. Microvilli
Introduction:
Cells are the smallest structural and the functional unit of life. The cell has many specialized structures that perform specific functions that are required for proper growth and development of an organism.
Answer to Problem 1MC
Correct answer:
The cells that are specialized to produce neurotransmitter, as well as hormones, have secretory vesicles.
Explanation of Solution
Justification for the correct answer:
Option (b) is given that secretory vesicles are associated with cells that produce neurotransmitters and hormones. The secretory vesicles perform the function of excretion from the cells. The hormones and neurotransmitters are excreted into the bloodstream from the cells through secretory vesicles. Hence, option (b) is correct.
Explanation for the incorrect answers:
Option (a) is given that cilia are associated with cells that produce neurotransmitters and hormones. The cilia are specialized structures on the surface of the cells and provide motility to the cell, in the case of prokaryotes. In the case of eukaryotes, they perform the function of moving the contents of the organs further. So, it is an incorrect option.
Option (c) is given that gap junction are associated with cells that produce neurotransmitters and hormones. Gap junctions mainly function to pass the ions as well as molecules freely through the cells. They help in establishing an electrical communication between the cells. So, it is an incorrect option.
Option (d) is given that microvilli are associated with cells that produce neurotransmitters and hormones. The cells whose main function is absorption have microvilli in or on them. The body organs like intestines and kidneys perform the function of absorption. Thus, the cells of these organs should have a large surface area. This is accomplished by the presence of structures that extend outward from the plasma membrane.
These structures are called microvilli. These provide a brushy lining. These increase the area of absorption of various nutrients. They also perform the function of secretion of some factors. So, it is an incorrect option.
Hence, options (a), (c), and (d) are incorrect.
Therefore, the cells that are specialized to secrete the chemical messengers like hormones, as well as neurotransmitters, accomplish their function by passing these substances into the blood through secretory vesicles.
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