A child dies following a series of chronic bacterial infections. At the autopsy, the physicians are startled to see that the child's white blood cells are loaded with vacuoles containing intact bacteria. Which of the following explanations could account for this finding?
A defect in the lysosomes of the white blood cells prevented the cells from destroying engulfed bacteria.
Which of the following statements about the cytoskeleton is false?
Once laid down, the elements of the cytoskeleton are fixed and remain permanently in place.
A scientist wants to examine living cells lining the respiratory tract to determine how the cells use tiny hairs to move dirt and mucus away from the lungs. Which of the following instruments would be best, and why?
a light microscope because it allows observations of whole, live cells
Which of the following statements about cellular metabolism (the breaking down & building of molecules) is false?
Cellular metabolism occurs in animal but not plant cells
The idea that all living things are composed of cells and that all cells come from other cells defines
A manufacturing company dumps its wastes into a nearby pond. One of the wastes is found to paralyze the contractile vacuoles of certain protists. A biologist looking at individual samples of these organisms taken from the pond would find that they
have gained water and burst
Your throat is dry, and you want the last cough drop in the box to last a long time in your mouth. What should you do?
Keep the cough drop whole.
Insulin is a protein that is produced by pancreatic cells and secreted into the bloodstream. Which of the following options correctly lists the order of the structures through which insulin passes from its production to its exit from the cell?
rough ER, transport vesicles, Golgi apparatus, transport vesicles, cell membrane
The cells that produce hair contain a lot of ______, while the cells that produce the oils that coat the hair contain a lot of _______.
rough endoplasmic reticulum... smooth endoplasmic reticulum
A scanning electron microscope is used to study ____, whereas a transmission electron microscope is used to study _____.
cell surfaces... internal cell structures
Unlinke animal cells, plant cells have _____ and ______. Unlike plant cells, animal cells have ______.
chloroplasts... cell walls... centrioles
The oil from the sebaceous glands is produced by which of the following cell organelles?
smooth endoplasmic reticulum
Which of the following statements about cells is true?
All cells have internal structures that move.
The membranous compartmentalization of a cell
allows different metabolic processes to occur simultaneously
Microfilaments differ from microtubules in that microfilaments
are mainly composed of actin, whereas microtubules are composed of tubulin
synthesis of membrane proteins, secretory proteins, and hydrolytic enzymes; formation of transport vesicles
lipid synthesis; carbohydrate metabolism in liver cells; detoxification in liver cells; calcium ion storage
modification, temporary storage, and transport of macromolecules; formation of lysosomes and transport needs
digestion of nutrients, bacterian, and damaged organelles; destruction of certain cells during embryonic development
maintenance of cell shape; anchorage for organelles; movement of organelles within cells; cell movement; mechanical transmission of signals from exterior of cell to interior
maintenance of cell shape and skeletal support; surface protection; binding of cells in tissues
binding of cells in tissues; surface protection; regulation of cellular activities
A cell is exposed to a substance that prevents it from dividing. The cell becomes larger and larger. This situation
will eventually be problematic, since the cell's ability to absorb nutrients through its outer membrane will not keep increasing as quickly as its cytoplasmic needs
It is essential for heart muscle cells to beat in a coordinated fashion. The cell junctions that would best facilitate this are
Which of the following statements about electron microscopes is true?
Electron microscopes focus electron beams to create a magnified image of an object.
Mitochondria differ from chloroplasts in that mitochondria
contain membrane folds called cristae, whereas chloroplasts contain disk-like vesicles in stacks called grana
When a cell is deprived of oxygen, its lysosomes tend to burst and release their contents into the cell. As a result of this, that cell will
undergo self-digestion and die
The endosymbiosis hypothesis proposes that
a small cell lived inside a larger cell to the benefit of both cells
A scientist wants to magnify a pollen grain 8,000 times and examine the ridges and pores on its surface. Which one of the following instruments would be best?
a scanning electron microscope
Which of the following statements regarding the Golgi apparatus is false?
The Golgi apparatus decreases in size when a cell increases its protein production.
Which of the following statements about the functions of a plant cell central vacuole is false?
The central vacuole of a plant cell may digest chemicals for recycling.
Which of the following cell structures is associated with the breakdown of harmful substances or substances that are no longer needed by the cell?
The plasma cell produces thousands of antibodies per second. What type of intracellular structure would you expect to be very prominent within the cell?
Which of the following statements about lysosomes is false?
Lysosomes synthesize proteins from the recycled amino acids
A drug that interferes with microtubule formation is likely to completely disrupt
the movements of sperm cells
Unlike animal cells, plant cells have _______ and _________. Unlike plant cells, animal cells have _________.
chloroplasts... cell walls... centrioles
The two main functions of the rough endoplasmic reticulum are the production of
membrane and proteins secreted by the cell
Which of the following statements regarding plasmodesmata is false?
Plasmodesmata are commonly found in single-celled organisms