Question 1

The figure below shows the beginning steps in the evolutionary process that biologists hypothesize led to the formation of the cell nucleus and the rise of eukaryotic cells.  Identify the process shown in the figure, and name a structure other than the nucleus that was likely formed in this same process.

Accepted Answer

The answer of The figure below shows the beginning steps...

Question 2

Which structure is not surrounded by one or more membranes?

Accepted Answer

Ribosomes are not surrounded by membranes. They are small organelles that consist of RNA and protein and are involved in protein synthesis.

Question 3

A student created the table below to compare the extracellular matrix of the animal cell with the plant cell wall.  Which statement correctly evaluates the accuracy of the table?

Accepted Answer

The table incorrectly states that the extracellular matrix (ECM) is found outside of the cell membrane in animal cells, when in fact it is only found in certain types of animal cells. The plant cell wall, on the other hand, is found in all plant cells and is located outside the cell membrane. Therefore, the descriptions of relationships to cells should be reversed.

Question 4

Which step is thought to have occurred, according to endosymbiotic theory?

Accepted Answer

The endosymbiotic theory suggests that an independent prokaryotic cell was engulfed by another independent prokaryotic cell. Over time, the engulfed cell lost some of its independent functions and became dependent on the host cell, leading to the evolution of complex eukaryotic cells.

Question 5

The diagram below shows a cutaway side view of a plant cell wall and cell membrane.  Which biological function is emphasized by the structure shown?

Accepted Answer

The diagram emphasizes the structural support of the whole plant, as it shows the plant cell wall providing mechanical strength and rigidity to the plant cell. The cell membrane, which is shown adjacent to the cell wall, serves as a selectively permeable barrier that regulates the movement of materials in and out of the cell, but it does not provide significant structural support.

Question 6

A vesicle carries a protein to the cell membrane, where it is inserted into the phospholipid bilayer.The vesicle budded off from which subcellular structure before making the trip through the cytoplasm to the cell membrane?

Accepted Answer

The trans-Golgi is responsible for packaging and sorting proteins, including those destined to be secreted or inserted into the cell membrane. Therefore, the vesicle carrying the protein likely budded off from the trans-Golgi before making its way to the cell membrane. The cis-Golgi is responsible for receiving proteins from the endoplasmic reticulum (ER), the rough ER is responsible for protein synthesis and folding, and the smooth ER is responsible for lipid synthesis and detoxification. While these structures may be involved in the overall process of protein sorting and transport, they are not the most likely starting point for the vesicle carrying the protein to the cell membrane. The medial-Golgi is situated between the cis- and trans-Golgi, and is involved in sorting and modifying proteins further, but again, the vesicle would have likely budded off from the trans-Golgi before reaching this point.

Question 7

Which statement can be used as evidence for the endosymbiosis theory?

Accepted Answer

Mitochondria and plastids having their own DNA that codes for some of their own proteins supports the endosymbiosis theory, which proposes that these organelles were once free-living prokaryotes that were engulfed by a larger cell in a symbiotic relationship. The presence of their own genetic material suggests that these organelles were once independent organisms.

Question 8

The cytoskeleton consists of

Accepted Answer

The cytoskeleton consists of three types of fibers: microtubules, intermediate filaments, and microfilaments. Cilia and flagella are made up of microtubules, and microfilaments play a role in muscle contractions and cell movement, but they are not the only components of the cytoskeleton. Internal cell walls and calcified microtubules are not part of the cytoskeleton.

Quiz 5: Cells: the Working Units of Life

Which structure is not surrounded by one or more membranes?

A student created the table below to compare the extracellular matrix of the animal cell with the plant cell wall. Which statement correctly evaluates the accuracy of the table?

Which step is thought to have occurred, according to endosymbiotic theory?

The diagram below shows a cutaway side view of a plant cell wall and cell membrane. Which biological function is emphasized by the structure shown?

A vesicle carries a protein to the cell membrane, where it is inserted into the phospholipid bilayer.The vesicle budded off from which subcellular structure before making the trip through the cytoplasm to the cell membrane?

Which statement can be used as evidence for the endosymbiosis theory?

The cytoskeleton consists of