All AP Biology Resources
Example Questions
Example Question #1 : Cell Structures
Which of the following cellular structures is not seen in both prokaryotes and eukaryotes?
DNA
Ribosomes
A cell wall
Mitochondria
Mitochondria
Prokaryotes do have organelles, but not complex, membrane-bound organelles. As a result, the membrane-bound mitochondria would not be seen in prokaryotes. Remember that plants are eukaryotes, and have cell walls just like prokaryotes. In addition, prokaryotes have ribosomes as well as DNA.
Example Question #1 : Cellular Biology
Prokaryotes, but not eukaryotes, lack which of the following structures?
Ribosomes
DNA
Flagella
Mitochondria
Mitochondria
Prokaryotes do not have membrane-bound organelles, such as mitochondria or an endoplasmic reticulum.
Flagella are hair-like structures that allow the cell to move, and are present in both prokaryotes and eukaryotes. Although prokaryotes don't have multiple chromosomes like eukaryotes, they do still have DNA in the form of a cyclic chromosome. Ribosomes are not bound by a membrane, and are essential to the process of translation, which creates proteins in the cell. Prokaryotes and eukaryotes possess ribosomes in order to form functional proteins.
Example Question #2 : Cellular Biology
Where does the electron transport chain occur in prokaryotic cells and eukaryotic cells, respectively?
The chloroplasts; the mitochondria
The chloroplasts; the cellular membrane
The mitochondria; the cellular membrane
The mitochondria; the mitochondria
The cellular membrane; the mitochondria
The cellular membrane; the mitochondria
Prokaryotes, such as bacteria, do not contain membrane-bound organelles such as the nucleus, mitochondria, and chloroplasts that we might find in a eukaryotic cell. Since we know the electron transport chain (ETC) is important in providing cellular energy, prokaryotes must still perform some form of this process. The complexes of the ETC are found in the actual cellular membrane that separates the cell from the environment in prokaryotes, while they are found in the inner mitochondrial membrane in eukaryotes. Eukaryotes are then able to generate a proton gradient between the two mitochondrial membranes within the intermembrane space, while prokaryotes can generate a gradient between the cell membrane and cell wall.
Example Question #1 : Understanding Eukaryotic And Prokaryotic Differences
Prokaryotes and eukaryotes are defined by a series of differences. Which of the following structures is found in one class of cell, but not the other?
Cell wall
Plasma membrane
Mitochondria
Ribosomes
Mitochondria
Prokaryotes do not have membrane-bound organelles, so they would not have mitochondria.
Cell walls and plasma membranes are found in both bacteria (prokaryotes) and plants (eukaryotes). Ribosomes are not bound by a membrane, and are mainly composed of rRNA; they are used for protein synthesis in both prokaryotes and eukaryotes.
Example Question #1 : Cell Structures
Which structure is present in prokaryotic cells, but not eukaryotic cells?
A cell membrane
80S ribosomes composed of one 60S and one 40S subunit
A nuclear envelope
Numerous organelles like mitochondria and lysosomes
A circular, double-stranded molecule of DNA as its main genetic material
A circular, double-stranded molecule of DNA as its main genetic material
In general, prokaryotic cells are smaller and less complex than eukaryotic cells. They lack membrane-bound organelles (such as mitochondria) and contain a nucleoid region instead of a membrane-bound nucleus. They do have ribosomes, but those are small (70S) and composed of one 30S and one 50S subunit. Only eukaryotic ribosomes are 80S. Finally, both prokaryotes and eukaryotes are encased in cell membranes.
One difference between prokaryotic and eukaryotic cells is the organization and storage of genetic material. Both use DNA in the double-helix structure. In eukaryotes, this DNA is stored as chromatin or chromosomes within the nucleus, but in prokaryotes it is stored in a circular bundle known as the nucleoid in the cytoplasm.
Example Question #2 : Understanding Eukaryotic And Prokaryotic Differences
Prokaryotic cells have __________.
a membrane-bound nucleus, but no lysosomes
a plasma membrane encasing the cell, but no membrane-bound organelles
a Golgi apparatus, but no membrane-bound nucleus
a nucleoid region, but no plasma membrane encasing the cell
mitochondria, but no nucleus
a plasma membrane encasing the cell, but no membrane-bound organelles
When comparing prokaryotes to eukaryotes, the main fact to remember is that prokaryotes do not contain membrane-bound organelles. This means they have no mitochondria, Golgi apparatus, or endoplasmic reticulum. They also lack a membrane-bound nucleus, although they do have genetic material located in a nucleoid region. Prokaryotic cells are surrounded by a plasma membrane, and some types of bacteria have cell walls as well.
Example Question #2 : Cell Structures
Which structure could be found in a prokaryotic cell?
Centrioles
Rough endoplasmic reticulum
Peroxisomes
Mitochondria
Plasma membrane
Plasma membrane
Prokaryotic cells differ from eukaryotic cells in that they lack any membrane-bound organelles, including a nucleus. Instead, prokaryotic cells simply have an outer plasma membrane, DNA nucleoid structure, and ribosomes.
Rough endoplasmic reticulum, peroxisomes, and mitochondria are all bound by their own plasma membranes, and are only found in eukaryotic cells. Centrioles are a component of the cytoskeleton of eukaryotic cells, but are not found in prokaryotes.
Example Question #2 : Understanding Eukaryotic And Prokaryotic Differences
A group of researchers in a laboratory have found what they believe to be an unknown organism. They notice that this organism lacks a nuclear membrane and mitochondria. Using this information, which of the following structures would this organism most likely possess?
Cilia
Endoplasmic reticulum
Chloroplasts
Lysosomes
Ribosomes
Ribosomes
The organism is likely a prokaryotic organism, since it lacks a nuclear membrane and mitochondria. Prokaryotes lack all membrane-bound organelles, including nuclei, mitochondria, endoplasmic reticulum, chloroplasts, and lysosomes.
Both prokaryotes and eukaryotes contain ribosomes. Ribosomes are not membrane-bound, and are primarily composed of rRNA. Prokaryotes require ribosomes in order to synthesize proteins.
Cilia are composed of microtubules. While many prokaryotes have cilia, we cannot draw any conclusions without knowing more about the identity of the organism.
Example Question #1 : Cell Structures
A prokaryotic cell contains which of the following?
Microtubules
Endoplasmic reticulum
Nucleus
Ribosomes
Golgi apparatus
Ribosomes
Prokaryotic cells are simple cells that lack membrane-bound nuclei and complex organelles. Endoplasmic reticulum, microtubules, and the Golgi apparatus are unique to eukaryotic cells, and will not be found in prokaryotes. Prokaryotes do, however, contain ribosomes, though smaller than the ribosomes in eukaryotic cells. Prokaryotes and eukaryotes are both capable of the main processes of the central dogma: DNA replication, transcription, and translation. For this to be possible, prokaryotes must contain DNA, transcription proteins, RNA, and ribosomes.
Example Question #9 : Cellular Biology
What structure can be found in all living cells?
Nucleolus
Mitochondria
Ribosomes
Cell wall
Nucleus
Ribosomes
Unlike eukaryotes, prokaryotes have no membrane-bound organelles. This means that they lack a nucleus, mitochondria, and other advanced cell structures.
All cells rely on protein components in order to function. Protein synthesis takes place on ribosomes, which can be found in all cell types. In prokaryotes, ribosomes are free floating the cytoplasm; in eukaryotes, ribosomes can be free floating in the cytoplasm, bound to the rough endoplasmic reticulum, in mitochondria, or in chloroplasts.