Cellular Differences
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Biology › Cellular Differences
A special dye bonds chiefly to the DNA in cells and is used to help visualize DNA under the microscope. After preparing a microscope slide from human intestine epithelium and observing, a researcher notices that there are differences in the concentration of the dye in the cells on the slide; some dye spots are denser or more defined than in other cells. Which of the following represents the most logical conclusion?
There are eukaryotic and prokaryotic cells in the sample
The dye is unable to bond to any DNA due to residual stomach acids and collects unevenly
Procedural error
There could only be Prokaryotic cells in the sample and the unevenness in dye concentration is due to the differing cell density across the microscope slide
None of these
Explanation
Eukaryotes and prokaryotes are distinguished based on a structure called the nucleus. Eukaryotes have a nucleus, which houses their genetic material. Prokaryotes do not have a nucleus; instead their DNA is localized in an area (i.e. it is not membrane bound). So if the researcher were to stain a sample containing both types of cells, the eukaryotic cells would have darker, more defined stains within their cells. This would indicate the presence of a more compacted and localized DNA than that found in prokaryotes.
A special dye bonds chiefly to the DNA in cells and is used to help visualize DNA under the microscope. After preparing a microscope slide from human intestine epithelium and observing, a researcher notices that there are differences in the concentration of the dye in the cells on the slide; some dye spots are denser or more defined than in other cells. Which of the following represents the most logical conclusion?
There are eukaryotic and prokaryotic cells in the sample
The dye is unable to bond to any DNA due to residual stomach acids and collects unevenly
Procedural error
There could only be Prokaryotic cells in the sample and the unevenness in dye concentration is due to the differing cell density across the microscope slide
None of these
Explanation
Eukaryotes and prokaryotes are distinguished based on a structure called the nucleus. Eukaryotes have a nucleus, which houses their genetic material. Prokaryotes do not have a nucleus; instead their DNA is localized in an area (i.e. it is not membrane bound). So if the researcher were to stain a sample containing both types of cells, the eukaryotic cells would have darker, more defined stains within their cells. This would indicate the presence of a more compacted and localized DNA than that found in prokaryotes.
Histones .
All of the answer choices are true.
are only found in eukaryotic cells
are only found in the nucleus
are protiens around which DNA coils
play a role in gene regulation
Explanation
Histones are proteins found in the nucleus of eukaryotic cells. DNA wraps itself around histones to further condense. Also, depending on how tightly the DNA is wrapped around the histones, it may or may not be availible for activity (e.g. replication or transcription). Cells modify the interaction between DNA and histones around certain genes under certain conditions to make those genes available or unavailable as needed.
Which of the following organelles is present in plant cells, but not in animal cells?
Chloroplasts
Mitochondria
Cell membrane
Nucleus
Rough endoplasmic reticulum
Explanation
Mitochondria are membrane-bound organelles found in both plant and animal cells, and provide energy for the cell by converting different forms of reactants into ATP. The cell membrane is present in both types of cells and separates the environment from the inside of the cell, and provides cell structure and protection. The rough endoplasmic reticulum is present in both types of cells and is responsible for the storage and packaging of proteins and vesicles. The nucleus is present in both types of cells and controls the general activities of the cell, including gene expression and cell division.
Of these answer choices, only chloroplasts are present in plants cells, but not animal cells. Plant cells are photosynthetic and create their own form of energy from sunlight. The photosynthesis occurs in the chloroplasts of plant cells, which contain the pigment chlorophyll.
Which of the following organelles is found in plant cells, but not in animal cells?
Chloroplasts
Mitochondria
Ribosomes
Nucleus
Explanation
Plant cells are very similar to animal cells, but receive energy from sunlight. As a result, they require chloroplasts in order to house the chlorophyll where photosynthesis takes place. Animal cells are incapable of photosynthesis, and do not contain chloroplasts.
The other listed structures are found in both animal and plant cells.
Histones .
All of the answer choices are true.
are only found in eukaryotic cells
are only found in the nucleus
are protiens around which DNA coils
play a role in gene regulation
Explanation
Histones are proteins found in the nucleus of eukaryotic cells. DNA wraps itself around histones to further condense. Also, depending on how tightly the DNA is wrapped around the histones, it may or may not be availible for activity (e.g. replication or transcription). Cells modify the interaction between DNA and histones around certain genes under certain conditions to make those genes available or unavailable as needed.
Which of the following organelles is found in plant cells, but not in animal cells?
Chloroplasts
Mitochondria
Ribosomes
Nucleus
Explanation
Plant cells are very similar to animal cells, but receive energy from sunlight. As a result, they require chloroplasts in order to house the chlorophyll where photosynthesis takes place. Animal cells are incapable of photosynthesis, and do not contain chloroplasts.
The other listed structures are found in both animal and plant cells.
Which of the following organelles is present in plant cells, but not in animal cells?
Chloroplasts
Mitochondria
Cell membrane
Nucleus
Rough endoplasmic reticulum
Explanation
Mitochondria are membrane-bound organelles found in both plant and animal cells, and provide energy for the cell by converting different forms of reactants into ATP. The cell membrane is present in both types of cells and separates the environment from the inside of the cell, and provides cell structure and protection. The rough endoplasmic reticulum is present in both types of cells and is responsible for the storage and packaging of proteins and vesicles. The nucleus is present in both types of cells and controls the general activities of the cell, including gene expression and cell division.
Of these answer choices, only chloroplasts are present in plants cells, but not animal cells. Plant cells are photosynthetic and create their own form of energy from sunlight. The photosynthesis occurs in the chloroplasts of plant cells, which contain the pigment chlorophyll.
In which of the following organisms are vacuoles not usually found?
Mammals
Plants
Fungi
Bacteria
Explanation
Vacuoles are membrane-bound structures that are found in bacterial, plant, fungal, and occasionally, animal cells. Vacuoles function in storage of water and waste and in maintenance of turgor pressure in plants.
In which of the following organisms are vacuoles not usually found?
Mammals
Plants
Fungi
Bacteria
Explanation
Vacuoles are membrane-bound structures that are found in bacterial, plant, fungal, and occasionally, animal cells. Vacuoles function in storage of water and waste and in maintenance of turgor pressure in plants.