Unit 3 MCQs

One of the most pronounced differences between animal and plant cells is

Which of the following organelles would only be found within a cell that was both eukaryotic and autotrophic?

After being formed by the ribosomes located on the endoplasmic reticulum, what is the next organelle to which a protein could be transported?

Which of the following are involved with the movement or transport of materials and organelles throughout the cell?

As they flow over rotten logs as a fluid sheet, slime molds appear to lack any partitioning into cell units; however, slime molds do become cellular when they change form to produce spores. And the surface of some parasitic flatworms and some insect tissues are a "syncytium" or layer of living material that contains many nuclei and cell organelles but lacks partitioning by cell membranes. These tissues consume food and produce wastes. In light of the cell theory that "all living things are composed of cells," then

Which is NOT a reason for the small size of cells?

A high-powered microscope that produces an image from scattered secondary electrons is the

Which statement is NOT true about bacteria?

An amino sugar called N-acetylmuramic acid is an important building block of the cell wall of some bacteria. Penicillin prevents this amino sugar from being incorporated into the bacterial cell wall. Therefore,

Most bacteria live in a solution that is hypotonic relative to the cytoplasm of the bacteria. The cell wall of a bacterium is a peptidoglycan polymer that is tightly cross-linked. This would therefore function to

Which of the following is NOT offered as evidence in support of the endosymbiotic theory, the belief that a eukaryotic cell has evolved as a "committee" of prokaryotic cells?

The nucleus is NOT important as the site of

Cell biologists have introduced radioactively labeled carbohydrates, fats and amino acids to living cells, allowed time for cell metabolism, and then disrupted the cells in a blender and separated out the various cell organelles from the cytoplasm. They found the radioactive molecules could soon be detected as part of various cellular compounds, although the visible cell structures appeared unchanged. This leads us to conclude that

Which is a true statement about ribosomes?

Which of these is NOT part of the endomembrane system of the cell?

Which is NOT true concerning the Golgi complex?

The springtail is a very common small insect that lives in rotten logs, rich soil, and other humid places. Its cuticle is water repelling (hydrophobic) except for a strange organ, the collophore, on its ventral side. Because it lacks the excretory organs of other insects, the springtail has this organ in contact with the water (it is responsible for ion balance and secretion of wastes). If we examined the cell structure of this collophore, we would expect to find a high number of

Each time the water in a cell freezes slowly, long sharp crystals spear through the membrane structures of the cell. However, in the frozen state, virtually no chemical reactions occur. The most likely explanation for the bad taste of meat that has "freezer burn" from repeated freezing is the destruction of

From your knowledge of the size of cell components and the process of centrifugation, what is the order (from first to last) that the nucleus and organelles will be extracted?

Cells that make up salivary glands would be expected to contain a relatively large amount of

Which of the following is the reason plants wilt on a hot summer day?

Which of the following functions does the lipid bilayer component of the cell membrane NOT provide for the cell?

Which statement is NOT true about the proteins in the plasma membrane?

Red blood cells come in many "blood types" including type A, type B, type AB, type O [lacking proteins A and B], Rh positive, and Rh negative [lacking Rh factor] and many others. If blood is transfused, the recipient detects any new or "foreign" proteins. These blood type proteins are

Freshwater protozoans react to a/an _____ environment by removing water through _____.

Which is NOT true about plant cell walls?

In speculating upon the origin of early cells and the cell membrane, which of the following statements is/are NOT plausible?

All life forms currently have a basic cell membrane so we presume that the earliest forms of life had this "fence" isolating the internal organization from the external chaos. It is likely that the primordial environment was acidic. In such a case, the cell membrane would have to include

A feature common to most transmembrane proteins is

The membrane of an animal cell would be impermeable to all of the following EXCEPT I. a large and primarily polar protein II. a small lipid based molecule III. starch

All of the following statements regarding membranes are correct EXCEPT

Which of the following signaling mechanisms represent a correctly matched pair?

What is the function of structure E?

Using the yeast signal transduction pathways, both types of mating cells release the mating factors.These factors bind to specific receptors on the correct cells,

What is most likely to happen to an animal's target cells that lack receptors for local regulators?

Which of the following is a likely explanation of why natural selection favored the evolution of signals for sexual reproduction?

In an experiment to track the movement of growth factor molecules from secretion to the point of receptor binding in a particular species of mammal, a student found a 20-fold reduction in mm traveled when in the presence of an adrenal hormone. This is in part attributable to which of the following?

When a neuron responds to a particular neurotransmitter by opening gated ion channels, theneurotransmitter is serving as which part of the signal pathway?

Which of the following is true for the signaling system in an animal cell that lacks the ability to produce GTP?

Which of the following is true of transcription factors?

Because most receptors are membrane proteins, which of the following is usually true?

Since steroid receptors are located intracellularly, which of the following is true?

Receptor tyrosine kinases (RTKs) are found at high levels on various cancer cells. A protein,Herceptin, has been found to bind to an RTK known as HER2. This information can now be utilized in breast cancer treatment if which of the following is true?

The receptors for a group of signaling molecules known as growth factors are often

Sutherland discovered that epinephrine signals

Which of the following is the best explanation for the inability of a specific animal cell to reduce the Ca2+ concentration in its cytosol compared with the extracellular fluid?

The toxin of Vibrio cholerae causes profuse diarrhea because it

Which of the following would be inhibited by a drug that specifically blocks the addition of phosphate groups to proteins?

Which of the following most likely would be an immediate result of growth factor binding to its receptor?

An inhibitor of phosphodiesterase activity would have which of the following effects?

Caffeine is an inhibitor of phosphodiesterase. Therefore, the cells of a person who has recently consumed coffee would have increased levels of

If a pharmaceutical company wished to design a drug to maintain low blood sugar levels, one approach might be to design a compound

An inhibitor of which of the following could be used to block the release of calcium from the endoplasmic reticulum?

Which of the following statements is true of signal molecules?

Which of the following is a correct association?

One inhibitor of cGMP is Viagra. It provides a signal that leads to dilation of blood vessels and increase of blood in the penis, facilitating erection. Since cGMP is inhibited, the signal is prolonged. The original signal that is now inhibited would have

A drug designed to inhibit the response of cells to testosterone would almost certainly result in which of the following?

In research on aging (both cellular aging and organismal aging), it has been found that aged cells do not progress through the cell cycle as they had previously. Which of the following would provide evidence that this is related to cell signaling?

If an adult person has a faulty version of the human analog to ced-4 of the nematode, which of the following is most likely to result?

Why has C. elegans proven to be a useful model for understanding apoptosis?