Concept explainers
Videos
Which of the following is/are found only in prokaryotic cells?
a. plasmids
b. a cytoskeleton
c. mitochondria
d. ribosomes
Introduction:
Prokaryotes are mostly single-celled organisms with a distinct cell wall for protection and a cell membrane that is involved in cell transport. These cells are less complex than a eukaryotic cell. A major difference is that prokaryotes do not have a discrete nucleus.
Answer to Problem 1MC
Correct answer:
Plasmids are found in prokaryotes only.
Explanation of Solution
Justification for the correct answer:
Option (a) is given that only prokaryotes contain plasmids. The plasmid is an extrachromosomal circular deoxyribonucleic acid (DNA) segment that contains essential genes that provide resistance to the organism against stressful conditions. This DNA material can be transferred to another cell during reproduction. The prokaryotic cell is very small in size and accommodating a single large chromosome is difficult, therefore these plasmids contain a lot of essential genes in addition to the DNA molecule. Hence, option (a) is correct.
Justification for incorrect answers:
Option (b) is given that the cytoskeleton is a part of the prokaryotic cell only. The cytoskeleton is present in all eukaryotic as well as prokaryotic cells. It is essential for providing a cell with its shape and cell movement. So, it is an incorrect option.
Option (c) is given that only prokaryotic cells have mitochondria. This is not true as these primitive cells lack in membrane-bound organelles. Mitochondria is an organelle used for producing energy in the cell. Instead of utilizing mitochondria, a prokaryotic cell makes the use of its cell membrane for aerobic respiration. So, it is an incorrect option.
Option (d) is given that ribosomes are unique to prokaryotes. All living cells have ribosomes as they help in the production of proteins which are important for life. The only difference is in the type of ribosomes in eukaryotes and prokaryotes. So, it is an incorrect option.
Hence, options (b), (c), and (d) are incorrect.
Thus, it can be concluded that only prokaryotes contain plasmids. Cytoskeleton and ribosomes are found in both eukaryotes and prokaryotes, while mitochondria are only found in eukaryotes.
Want to see more full solutions like this?
Chapter 4 Solutions
Biology: Life on Earth (11th Edition)
- Selection of Traits What adaptations do scavengers have for locating and feeding on prey? What adaptations do predators have for capturing and consuming prey?arrow_forwardCompetition Between Species What natural processes limit populations from growing too large? What are some resources organisms can compete over in their natural habitat?arrow_forwardSpecies Interactions Explain how predators, prey and scavengers interact. Explain whether predators and scavengers are necessary or beneficial for an ecosystem.arrow_forward
- magine that you are conducting research on fruit type and seed dispersal. You submitted a paper to a peer-reviewed journal that addresses the factors that impact fruit type and seed dispersal mechanisms in plants of Central America. The editor of the journal communicates that your paper may be published if you make ‘minor revisions’ to the document. Describe two characteristics that you would expect in seeds that are dispersed by the wind. Contrast this with what you would expect for seeds that are gathered, buried or eaten by animals, and explain why they are different. (Editor’s note: Providing this information in your discussion will help readers to consider the significance of the research).arrow_forwardWhat is the difference between Uniporters, Symporters and Antiporters? Which of these are examples of active transport?arrow_forwardWhat are coupled transporters?arrow_forward
- How do histamine and prostaglandins help in the mobilization of leukocytes to an injury site? What are chemotactic factors? How do they affect inflammation process?arrow_forwardCompare and contrast neutrophils and macrophages. Describe two ways they are different and two ways they are similar.arrow_forwardDescribe the effects of three cytokines (not involved in the initial inflammation response). What cells release them?arrow_forward
