27
Which element of the cell theory has practical applications in health care because it promotes the use of sterilization and disinfection?
  1. All cells come from pre-existing cells.
  2. All living organisms are composed of one or more cells.
  3. A cell is the basic unit of life.
  4. A nucleus and organelles are found in prokaryotic cells.
28
What are the advantages and disadvantages of light microscopes? What are the advantages and disadvantages of electron microscopes?
  1. Advantage: In light microscopes, the light beam does not kill the cell. Electron microscopes are helpful in viewing intricate details of a specimen and have high resolution. Disadvantage: Light microscopes have low resolving power. Electron microscopes are costly and require killing the specimen.
  2. Advantage: Light microscopes have high resolution. Electron microscopes are helpful in viewing surface details of a specimen. Disadvantage: Light microscopes kill the cell. Electron microscopes are costly and low resolution.
  3. Advantage: Light microscopes have high resolution. Electron microscopes are helpful in viewing surface details of a specimen. Disadvantage: Light microscopes can be used only in the presence of light and are costly. Electron microscopes uses short wavelength of electrons and hence have lower magnification.
  4. Advantage: Light microscopes have high magnification. Electron microscopes are helpful in viewing surface details of a specimen. Disadvantage: Light microscopes can be used only in the presence of light and have lower resolution. Electron microscopes can be used only for viewing ultra-thin specimens.
29
Mitochondria are observed in plant cells that contain chloroplasts. Why do you find mitochondria in photosynthetic tissue?
  1. Mitochondria are not needed but are an evolutionary relic.
  2. Mitochondria and chloroplasts work together to use light energy to make sugars.
  3. Mitochondria participate in the Calvin cycle/light independent reactions of photosynthesis.
  4. Mitochondria are required to break down sugars and other materials for energy.
30
In what situation, or situations, would the use of a light microscope be ideal? Why?
  1. A light microscope is used to view the details of the surface of a cell as it cannot be viewed in detail by the transmission microscope.
  2. A light microscope allows visualization of small living cells, which have been stained and cannot be viewed by scanning electron microscope.
  3. A standard light microscope is used to view living organisms with little contrast to distinguish them from the background, which would be harder to see with the electron microscope.
  4. A light microscope reveals the internal structures of a cell, which cannot be viewed by transmission electron microscopy.
31
The major role of the cell wall in bacteria is protecting the cell against changes in osmotic pressure, pressure caused by different solute concentrations in the environment. Bacterial cells swell, but do not burst, in low solute concentrations. What happens to bacterial cells if a compound that interferes with the synthesis of the cell wall is added to an environment with low solute concentrations?
  1. Bacterial cells will shrink due to the lack of cell wall material.
  2. Bacterial cells will shrink in size.
  3. Bacterial cells may burst due to the influx of water.
  4. Bacterial cells remain normal; they have alternative pathways to synthesize cell walls.
32
We have discussed the upper limits of cell size; yet, there is a lower limit to cell size. What determines how small a cell can be?
  1. The cell should be large enough to escape detection.
  2. The cell should be able to accommodate all the structures and metabolic activities necessary to survival.
  3. The size of the cell should be large enough to reproduce itself.
  4. The cell should be large enough to adapt to the changing environmental conditions.
33
Which of these is a possible explanation for the presence of a rigid cell wall in plants?
  1. Plants remain exposed to changes in temperature and thus require rigid cell walls to protect themselves.
  2. Plants are subjected to osmotic pressure and a cell wall helps them against bursting or shrinking.
  3. Plant cells have a rigid cell wall to protect themselves from grazing animals.
  4. Plant cells have a rigid cell wall to prevent the influx of waste material.
34
Bacteria do not have organelles; yet, the same reactions that take place on the mitochondria inner membrane, the phosphorylation of ADP to ATP, and chloroplasts, photosynthesis, take place in bacteria. Where do these reactions take place?
  1. These reactions take place in the nucleoid of the bacteria.
  2. These reactions occur in the cytoplasm present in the bacteria.
  3. These reactions occur on the plasma membrane of bacteria.
  4. These reactions take place in the mesosomes.
35
What are the structural and functional similarities and differences between mitochondria and chloroplasts?
  1. Similarities: double membrane, inter-membrane space, ATP production, contain DNA. Differences: mitochondria have inner folds called cristae, chloroplast contains accessory pigments in thylakoids, which form grana and a stroma.
  2. Similarities: DNA, inter-membrane space, ATP production, and chlorophyll. Differences: mitochondria have a matrix and inner folds called cristae; chloroplast contains accessory pigments in thylakoids, which form grana and a stroma.
  3. Similarities: double membrane and ATP production. Differences: mitochondria have inter-membrane space and inner folds called cristae; chloroplast contains accessory pigments in thylakoids, which form grana and a stroma.
  4. Similarities: double membrane and ATP production. Differences: mitochondria have inter-membrane space, inner folds called cristae, ATP synthase for ATP synthesis, and DNA; chloroplast contains accessory pigments in thylakoids, which, form grana and a stroma.
36
Is the nuclear membrane part of the endomembrane system? Why or why not?
  1. The nuclear membrane is not a part of the endomembrane system as the endoplasmic reticulum is a separate organelle of the cell.
  2. The nuclear membrane is considered a part of the endomembrane system as it is continuous with the Golgi body.
  3. The nuclear membrane is part of the endomembrane system as it is continuous with the rough endoplasmic reticulum.
  4. The nuclear membrane is not considered a part of the endomembrane system as the nucleus is a separate organelle.
37
What happens to the proteins that are synthesized on free ribosomes in the cytoplasm? Do they go through the Golgi apparatus?
  1. These proteins move through the Golgi apparatus and enter in the nucleus.
  2. These proteins go through the Golgi apparatus and remain in the cytosol.
  3. The proteins do not go through the Golgi apparatus and move into the nucleus for processing.
  4. The proteins do not go through the Golgi apparatus and remain free in the cytosol.
38
What are the similarities and differences between the structures of centrioles and flagella?
  1. Centrioles and flagella are made of microtubules but show different arrangements.
  2. Centrioles are made of microtubules but flagella are made of microfilaments and both show the same arrangement.
  3. Centrioles and flagella are made of microfilaments. Centrioles have a 9 + 2 arrangement.
  4. Centrioles are made of microtubules and flagella are made of microfilaments and both have different structures.
39
Inhibitors of microtubule assembly, vinblastine for example, are used for cancer chemotherapy. How does an inhibitor of microtubule assembly affect cancerous cells?
  1. The inhibitors restrict the separation of chromosomes, thereby stopping cell division.
  2. The inhibition of microtubules interferes with the synthesis of proteins.
  3. The inhibitors bind the microtubule to the nuclear membrane, stopping cell division.
  4. The inhibitor interferes with energy production.
40
How do cilia and flagella differ?
  1. Cilia are made of microfilaments and flagella of microtubules.
  2. Cilia are helpful in the process of engulfing food. Flagella are involved in the movement of the organism.
  3. Cilia are short and found in large numbers on the cell surface whereas flagella are long and fewer in number.
  4. Cilia are found in prokaryotic cells and flagella in eukaryotic cells.
41
In which human tissues would you find desmosomes? Think of tissues that undergo strong mechanical stress and must be held together with some flexibility.
  1. bone cells and cartilage cells
  2. muscle cells and skin cells
  3. nerve cells and muscle cells
  4. secretory cells and muscle cells
42
If there is a mutation in the gene for collagen, such as the one involved in Ehlers-Danlos syndrome, and the individual produces defective collagen, how would it affect coagulation?
  1. The syndrome affects the clotting factors and platelet aggregation.
  2. The disease leads to hyper-coagulation of blood.
  3. Coagulation is not affected because collagen is not required for coagulation.
  4. The disease occurs due to the breakdown of platelets.
43
How does the structure of a plasmodesma differ from that of a gap junction?
  1. Gap junctions are essential for transportation in animal cells and plasmodesmata are essential for the movement of substances in plant cells.
  2. Gap junctions are found to provide attachment in animal cells and plasmodesmata are essential for attachment of plant cells.
  3. Plasmodesmata are essential for communication between animal cells and gap junctions are necessary for attachment of cells in plant cells.
  4. Plasmodesmata help in transportation and gap junctions help in attachment, in plant cells.