Some types of cells move freely through the body, while others are bound into tightly knit communities.
True
________ is a molecular "ferry" that brings amino acids to the ribosome to build a protein.
t-RNA
There is only one cell type in the human body that has a flagellum.
True
DNA transcription is another word for DNA replication.
False
In which stage of mitosis do the identical sets of chromosomes uncoil and resume their chromatin form?
telophase
Which of the following names the three main parts of a human cell?
cytoplasm, plasma membrane, and nucleus
The RNA responsible for bringing the amino acids to the ribosome for protein formation is ________.
tRNA
Each daughter cell resulting from mitotic cell division has exactly as many chromosomes as the parent cell.
True
Which of the following is NOT a concept of the cell theory?
Cells are given life through a process known as spontaneous generation.
The plasma membrane is made primarily of ________.
phospholipids
The figure is of which cellular organelle?
a mitochondrion
Which of the following would not be a constituent of a plasma membrane?
messenger RNA
What is the primary function of the mitochondria?
They are the main sites of ATP production.
Which of the following is characteristic of cilia?
They are whiplike, motile cellular extensions that occur in large numbers on the exposed surfaces of certain cells.
Why is the selective permeability of the plasma membrane essential for normal cell function?
Selective permeability allows cells to exclude some substances and allow others to pass into or out of the cell.
The functions of centrioles include ________.
organizing the mitotic spindle in cell division
What type of protein is indicated by the arrow?
histone
Passive membrane transport processes include ________.
movement of a substance down its concentration gradient
________ is the diffusion of a solvent, such as water, across a selectively permeable membrane.
Osmosis
Which vesicular transport process occurs primarily in some white blood cells and macrophages?
phagocytosis
If cells are placed in a hypertonic solution containing a solute to which the membrane is impermeable, what could happen?
The cells will lose water and shrink.
The main component of the cytosol is ________.
Water
Once solid material is phagocytized and taken into a vacuole, which of the following statements best describes what happens?
A lysosome combines with the vacuole and digests the enclosed solid material.
The electron microscope has revealed that one of the components within the cell consists of pinwheel array of 9 triplets of microtubules arranged to form a hollow tube. This structure is a ________.
centriole
Lipid rafts, found in the cell outer membrane surface, are concentrating platforms for certain receptor molecules or for protein molecules needed for cell signaling..
True
Which of the following statements correctly describes the plasma membrane?
It is a dynamic fluid structure that is in constant flux.
Lysosomes perform digestive functions within a cell.
True
Which of the following is FALSE regarding the membrane potential?
The resting membrane potential is maintained solely by passive transport processes.
Some hormones enter cells via ________.
receptor-mediated endocytosis
Which set of membrane proteins in the figure depicts the transport of solute molecules?
A
What is the function of the indicated protein?
to allow DNA to form a compact structure
The structure indicated by B is ______.
the Golgi apparatus
Which of the following is a principle of the fluid mosaic model of cell membrane structure?
Phospholipids form a bilayer that is largely impermeable to water-soluble molecules.
The orderly sequence of the phases of mitosis is prophase, metaphase, anaphase, and telophase.
True
What must happen before a body cell can begin mitotic cell division?
Its DNA must be replicated exactly so that identical copies of the cell's genes can be passed on to each of its offspring.
What is the specific role of the enzyme indicated by B during the formation of the new DNA strands?
joining the nucleotides that form the new DNA strand
During DNA replication, the covalent bonding of nucleotides into a new strand of DNA is performed by ________.
DNA polymerase
Diffusion is a form of active transport.
False
What is a function of the enzyme indicated by structure A?
breaking the bonds between complementary base pairs
Which of the following describes the plasma membrane?
the phospholipid bilayer surrounding the cell