Question 1

A student collects water from a freshwater pond and views samples of the water under a microscope.She observes several unicellular organisms and begins to classify them as prokaryotic or eukaryotic.To do this, she looks for the presence or absence of _______ structures inside the cells.

Accepted Answer

The answer of A student collects water from a freshwater...

Question 2

Some proteins on the surface of a mammalian cell contain carbohydrates.These proteins are synthesized by _______ and the sugars are added in the _______.

Accepted Answer

Proteins with carbohydrates on their surface are glycoproteins. These are synthesized by ribosomes on the rough endoplasmic reticulum and the sugars are added in the Golgi apparatus before the final protein is transported to the cell membrane.

Question 3

A biologist discussing the discovery of horseshoe crab fossils that date to 445 mya mentions that these fossils were the ancestors of horseshoe crabs living today.Which biological principle does this illustrate?

Accepted Answer

The principle that life is continuous is illustrated by the fact that horseshoe crabs living today are descended from ancient ancestors, showing an unbroken lineage over millions of years.

Question 4

What property of organelles and other subcellular structures is used to separate them using the lab technique known as cell fractionation?

Accepted Answer

The answer of What property of organelles and other subcellular...

Question 5

Refer to the figure below.  The villi of the small intestine are lined with epithelial cells that absorb nutrients from digested food on one side and transfer these nutrients into the blood on the other side.Which cell shown in the figure would be most efficient as an epithelial cell in the intestinal villi, and why?

Accepted Answer

The most efficient epithelial cell in the intestinal villi would be the one with the highest surface area-to-volume ratio, as this would allow for the most efficient absorption of nutrients. Cell A has a larger surface area-to-volume ratio than cell B, making it the most efficient cell for this function.

Question 6

Refer to the figure below.  The figure depicts a theoretical model describing an evolutionary process involving invagination of the cell membrane to form the _______ system that is now observed in all modern eukaryotes.

Accepted Answer

The answer of Refer to the figure below.  The...

Question 7

If all the lysosomes within a cell suddenly ruptured, what would be the most likely result?

Accepted Answer

Lysosomes contain hydrolytic enzymes that break down macromolecules into their smaller subunits. If all the lysosomes within a cell suddenly ruptured, these enzymes would be released into the cytoplasm, where they could hydrolyze proteins, lipids, carbohydrates, and other biomolecules. This would likely result in a loss of cellular function and could potentially lead to cell death. More proteins would not be made, as the machinery responsible for protein synthesis would also be affected by the lysosomal rupture. The DNA in mitochondria would not be directly affected by lysosomal rupture, and the division of mitochondria and chloroplasts is not related to lysosome function. Therefore, the most likely result of lysosomal rupture would be the breakdown of proteins in the cytosol.

Question 8

How might a researcher study the presence of a specific protein in cells from different tissues of the body?

Accepted Answer

Treating cells with a dye that selectively binds to the protein of interest and then using light microscopy to look for evidence of this dye in cells would be the most effective way to study the presence of a specific protein in cells from different tissues of the body. This technique is known as immunofluorescence staining and allows for the specific visualization of the protein in question.

Question 9

Refer to the diagram below.  The diagram illustrates the early steps in the evolution of eukaryotes according to the theory of _______.

Accepted Answer

The answer of Refer to the diagram below.  The...

Question 10

Five statements about cell membranes are given.Which statement can be used to explain the importance of the cell membrane to cell survival?

Accepted Answer

The selective permeability of the cell membrane allows the cell to control what enters and exits, which is crucial for maintaining homeostasis and survival.

Question 11

Plastids are

Accepted Answer

Plastids are organelles that are only present in nearly all plant cells. While they are most commonly associated with photosynthesis, they also serve other functions such as storage and pigment synthesis. Plastids are not present in all eukaryotes, are not always green, are not present in photosynthetic prokaryotes, and are distinct from mitochondria.

Question 12

Researchers studying a proteolytic enzyme observed that it could not be found free in the cytoplasm but was localized inside lysosomes within the cytoplasm.This compartmentalization of proteolytic enzymes _______ the cell against unwanted digestion of cytoplasmic proteins.

Accepted Answer

The answer of Researchers studying a proteolytic enzyme observed that...

Question 13

Suppose you are observing both prokaryotic and eukaryotic cells, using light microscopy.Your microscope has objectives that can be adjusted to give the following magnifications: 2X, 4X, 10X, 20X, and 100X.If you use the 10X objective to observe human cells with a diameter of 80 $\mu$m, you will likely need to use the _______ objective to observe bacterial cells.

Accepted Answer

The answer of Suppose you are observing both prokaryotic and...

Question 14

Refer to the figure below.  Which numbers represent cytoplasm, pili, ribosome, and cell wall, in that order?

Accepted Answer

The answer of Refer to the figure below.  Which...

Question 15

Which structure is present in some prokaryotic cells?

Accepted Answer

Capsules are present in some prokaryotic cells and are a protective layer made of polysaccharides or proteins. Chloroplasts, nuclei, mitochondria, and microtubules are structures found in eukaryotic cells.

Question 16

The major factor limiting cell size is the

Accepted Answer

As cells grow larger, their volume increases much more quickly than their surface area. This means that a larger cell has a smaller ratio of surface area to volume, which can limit the cell's ability to efficiently exchange materials with the environment. This can lead to problems such as inadequate nutrient uptake and waste removal. Therefore, the ratio of surface area to volume is the major factor limiting cell size.

Question 17

Refer to the sketch of a prokaryote below.  The arrow points to the nucleoid, a region that contains a single molecule of _______.

Accepted Answer

The answer of Refer to the sketch of a prokaryote...

Question 18

The diagram below shows the interface between a blood vessel and several kidney cells.The arrows indicate the direction of flow of molecules from the blood into the kidneys to form urine.The extracellular matrix is shown lying between the kidney cells and the cells lining the blood vessel walls.  This is an example of an extracellular matrix functioning in _______ of molecules, ensuring that proteins are retained in the blood while water, salts, and other small molecules pass into the urine.

Accepted Answer

The answer of The diagram below shows the interface between...

Question 19

Refer to the figure below.  The flowchart can be completed by filling in the unlabeled boxes with the word _______ to identify the structures used to transport proteins both between organelles and to the cell exterior, where they are secreted into the external environment.

Accepted Answer

The answer of Refer to the figure below.  The...

Question 20

Which lab procedure is the best to use to determine whether a newly discovered single-celled organism is prokaryotic or eukaryotic?

Accepted Answer

The presence or absence of membrane-bound structures is the main differentiating factor between prokaryotic and eukaryotic cells. Transmission electron microscopy allows for visualization of these structures at a high resolution, making it the best lab procedure to determine the type of cell. Chemical analysis of the cell membrane (B) does not necessarily indicate whether the cell is prokaryotic or eukaryotic. Staining cells for ribosomes (C) can indicate whether the cells have ribosomes, but this does not distinguish between prokaryotic and eukaryotic cells since both have ribosomes. Biochemical methods for determining cell wall composition (D) and the ability to carry out photosynthesis also do not definitively differentiate between prokaryotes and eukaryotes. Analyzing the number of genes encoded in the DNA (E) can provide information on the complexity of the organism, but does not necessarily determine whether it is prokaryotic or eukaryotic.

Quiz 5: Cells: the Working Units of Life

A student collects water from a freshwater pond and views samples of the water under a microscope.She observes several unicellular organisms and begins to classify them as prokaryotic or eukaryotic.To do this, she looks for the presence or absence of _______ structures inside the cells.

Some proteins on the surface of a mammalian cell contain carbohydrates.These proteins are synthesized by _ and the sugars are added in the _.

A biologist discussing the discovery of horseshoe crab fossils that date to 445 mya mentions that these fossils were the ancestors of horseshoe crabs living today.Which biological principle does this illustrate?

What property of organelles and other subcellular structures is used to separate them using the lab technique known as cell fractionation?

Refer to the figure below. The figure depicts a theoretical model describing an evolutionary process involving invagination of the cell membrane to form the _______ system that is now observed in all modern eukaryotes.

If all the lysosomes within a cell suddenly ruptured, what would be the most likely result?

How might a researcher study the presence of a specific protein in cells from different tissues of the body?

Refer to the diagram below. The diagram illustrates the early steps in the evolution of eukaryotes according to the theory of _______.

Five statements about cell membranes are given.Which statement can be used to explain the importance of the cell membrane to cell survival?

Plastids are

Researchers studying a proteolytic enzyme observed that it could not be found free in the cytoplasm but was localized inside lysosomes within the cytoplasm.This compartmentalization of proteolytic enzymes _______ the cell against unwanted digestion of cytoplasmic proteins.

Refer to the figure below. Which numbers represent cytoplasm, pili, ribosome, and cell wall, in that order?

Which structure is present in some prokaryotic cells?

The major factor limiting cell size is the

Refer to the sketch of a prokaryote below. The arrow points to the nucleoid, a region that contains a single molecule of _______.

Refer to the figure below. The flowchart can be completed by filling in the unlabeled boxes with the word _______ to identify the structures used to transport proteins both between organelles and to the cell exterior, where they are secreted into the external environment.

Which lab procedure is the best to use to determine whether a newly discovered single-celled organism is prokaryotic or eukaryotic?