chapter 4 practice test

Which tissue would likely contain large amounts of anchoring junctions?

Your Answer: bone tissue Correct Answer: stomach tissue No. Anchoring junctions are more likely to be found in tissues that undergo mechanical stress and stretching, such as skin and muscle.

The eyepiece of a light microscope has a magnification level of 10x. If you were looking at a paramecium under the lowest-power objective (4x), what would be the total magnification of the microscope at this setting?

40x Correct. Total magnification is (4x) × (10x) = 40x.

What is the relationship between the Golgi apparatus and the plasma membrane?

The finished products of the Golgi apparatus may leave the cell through vesicles that fuse with the plasma membrane. Correct. Transport vesicles from the Golgi move to the plasma membrane for export. In some cases the finished products become part of the plasma membrane or part of another organelle.

One function of the central vacuole in plant cells is facilitating cell growth: the central vacuole absorbs water and increases in size, expanding the volume and size of the plant cell while doing so. Animal cells, however, do not grow by this method. What is an essential difference between animal and plant cells that could explain how a plant cell can withstand this expansion of the central vacuole?

The plant cell wall provides a more rigid structure. Correct. The plant cell can use the central vacuole for growth because the cell wall is rigid.

How are cell surface proteins exported out of the cell?

The protein is folded, then packaged for transport to the Golgi apparatus. Correct. The protein structure is critical to the normal function of the protein. Once folded, then it will be transported to the Golgi apparatus via a transport vesicle.

What do the rough endoplasmic reticulum, Golgi apparatus, and lysosomes have in common?

They are constructed of interrelated membranes. Correct. Each of these organelles is a member of the endomembrane system and is constructed of the same type of membrane.

A 100 mm x 100 mm x 100 mm cell has a surface area that is _____ and a volume that is _____. A second cell, that is 10 mm x 10 mm x 10 mm, has a _____ surface-to-volume ratio when compared to the first cell.

Your Answer: 60,000 mm2 ... 1,000,000 mm3 ... larger Correct. The smaller cell has a larger surface (600 mm2) to volume (1,000 mm3) ratio. This accounts for why most cells are microscopic.

Which of the following cytoplasmic structures functions in the transport of vesicles from the endoplasmic reticulum to the Golgi apparatus?

Your Answer: actin filaments Correct Answer: microtubules No. Actin filaments support a cell's shape.

Which of the following structures is essential for the successful operation of the endomembrane system?

Your Answer: anchoring junctions Correct Answer: transport vesicles No. Anchoring junctions connect adjacent cells together with cytoskeletal fibers.

What changes would you expect to see in the liver cells of someone suffering from chronic alcoholism?

Your Answer: decreased levels of DNA synthesis Correct Answer: increased levels of endoplasmic reticulum activity No. Alcohol would not affect the level of DNA synthesis.

What component of the cell membrane connects signals from the outside of the cell with the inside of the cell and vice versa?

Your Answer: extracellular matrix Correct Answer: integrins The extracellular matrix helps hold cells together and protects and supports the plasma membrane.

A disease called primary ciliary dyskenisia is characterized by abnormal ciliary movements. In these cilia, microtubule functioning is disrupted due to microtubules missing an essential component. This disease could be caused by __________.

Your Answer: lack of actin proteins Correct Answer: lack of dynein proteins Actin proteins make up microfilaments, not microtubules.

If you wished to clearly observe the organelles inside of a white blood cell, which type of microscope would you choose?

Your Answer: light microscope Correct Answer: transmission electron microscope This type of microscope might allow you to discern some organelles--if the organelles are stained to increase contrast--but there is another microscope with higher resolution that allows us to more clearly see the internal structures of cells.

What mitochondrial feature enhances cellular respiration?

Your Answer: matrix Correct Answer: cristae Mitochondrial DNA, ribosomes, and enzymes involved in the process of cellular respiration are found in the intermembrane space, but they do not enhance the mitochondrion's ability to produce ATP.

Which of the following organelles is found only in animal cells and NOT in most plant cells?

Your Answer: peroxisome Correct Answer: lysosome Both plants and animals have this organelle.

Which of the following would distinguish a bacterial cell from an animal cell?

Your Answer: replication of DNA Correct Answer: presence of a cell wall No. Both a bacterial and an animal cell need to replicate their DNA to produce new cells.

Which cell structure is responsible for metabolism?

Your Answer: smooth endoplasmic reticulum Correct Answer: mitochondrion No. The smooth endoplasmic reticulum is involved in lipid synthesis and detoxification of liver cells, as well as calcium ion storage.

Which is a typical function of lysosomes?

breaking down of damaged organelles, such as chloroplasts Correct. Lysosomes do break down damaged organelles; lysosomes are rarely found in plant cells.

Many researchers think that the first eukaryotic cells obtained energy for life-sustaining functions from organic compounds. Given this information, which of the following organelles most likely appeared last in eukaryotic cells?

chloroplast Correct. If the earliest eukaryotic cells had contained chloroplasts, they would not have had to obtain organic compounds through food.

Which technique allowed scientists to figure out that all cells, and not just muscle cells, contained actin filaments?

electron microscopy Correct. In the 1960s, staining actin filaments and visualizing them with an electron microscope allowed scientists to discover that these structures are present in all cells.

Where are chlorophyll molecules located within the chloroplasts?

embedded in the thylakoid membrane Correct. Chlorophyll molecules are embedded within the thylakoid membrane, which is the most extensive membrane system within plant cells.

The cells of a person with adrenoleukodystrophy (ALD) swell with a buildup of fatty acids. In other words, fatty acids are not being broken down. Which organelle is most likely failing to function correctly?

lysosome Correct. This organelle functions to remove unwanted or unneeded material from the cell.

You have identified a new organism. It has ribosomes, plasmodesmata, and cell walls made of cellulose. This new organism is most likely a(n) __________.

plant Correct. Plant cells have cell walls that are made of cellulose and plasmodesmata, which are cytoplasmic channels that connect adjacent cells.

Which plant structure is most like gap junctions in animal cells?

plasmodesmata Correct. Plasmodesmata form channels between adjacent plant cells which have a similar function to gap junctions in animal cells.

Pancreatic cells produce large amounts of protein. About how many ribosomes would you expect there to be in a pancreatic cell?

several million Correct. There are several million ribosomes in cells, such as the cells in the pancreas that produce digestive enzymes.

The plasma membrane would fit into which general function category?

support, movement, and communication Correct. The plasma membrane is an important structure for cell communication with the external environment.