Chapter 4: The Cell: Anatomy and Division
Define cell.
The cell is the basic structural and functional unit of living organisms.
When a cell is not dividing, the DNA is loosely spread throughout the nucleus in a threadlike form called:
a. chromatin
b. chromosomes
c. cytosol
d. ribosomes
a. chromatin
The plasma membrane not only provides a protective boundary for the cell but also determines which substrates enter or exit the cell. We call this characteristic:
a. diffusion
b. membrane potential
c. osmosis
d. selective permeability
d. selective permeability
Proteins are assembled on these organelles.
ribosomes
Because these organelles are responsible for providing most of the ATP that the cell needs, they are often referred to as the "powerhouses" of the cell. They are the:
a. centrioles
b. lysosomes
c. mitochondria
d. ribosomes
c. mitochondria
Choose the correct term:
During cytokinesis/interphase the cell grows and performs its usual activities.
interphase
True/False:
The end product of mitosis is four genetically identical daughter nuclei.
False.
How many stages of mitosis are there?
4: prophase, metaphase, anaphase, and telophase.
DNA replication occurs during:
a. cytokinesis
b. interphase
c. metaphase
d. prophase
b. interphase
True/False:
All animal cells have a cell wall.
False. All animal cells have a cell membrane. Bacteria and plants have cell walls.
Define organelle.
"small organ"
Structures in the cytoplasm responsible for specific functions within the cell related to metabolism.
Define cell.
The structural and functional unit of all living things.
Cells have differences that reflect their specific functions in the body, but what functions do they have in common?
maintain boundaries
metabolize
digest nutrients
eliminate waste
grow
reproduce
respond to stimulus
move
Identify the following cell structure:
external boundary of cell; regulates flow of materials into and out of the cell; site of cell signalling.
plasma membrane
Identify the following cell structure:
contains digestive enzymes of many varieties; "suicide sac" of the cell
lysosomes
Identify the following cell structure:
scattered throughout the cell, major site of ATP synthesis
mitochondria
Identify the following cell structure:
slender extensions of the plasma membrane that increase its surface area
microvilli
Identify the following cell structure:
stored glycogen granules, crystals, pigments; present in some cell types
inclusions
Identify the following cell structure:
membranous system consisting of flattened sacs and vesicles; packages proteins for export
Golgi apparatus
Identify the following cell structure:
control center for the cell; necessary for ell division and cell life
nucleus
Identify the following cell structure:
two rod-shaped bodies near the nucleus; associated with the formation of the mitotic spindle
centrioles
Identify the following cell structure:
dense nuclear body; packaging site for ribosomes
nucleolous
Identify the following cell structure:
contractile elements of the cytoskeleton
microfilaments
Identify the following cell structure:
membranous tubules covered with ribosomes; involved with intracellular transport of proteins
rough endoplasmic reticulum
Identify the following cell structure:
attached to membrane systems or scattered through cytoplasm; site of protein synthesis
ribosomes
Identify the following cell structure:
threadlike structures in nucleus; contain genetic material (DNA)
chromatin
Identify the following cell structure:
site of free radical detoxification
peroxisomes
For the following cell type, name one important structural characteristic observed in the laboratory and the function that structure complements or ensures.
squamous epithelium
tightly fitted, flattened cells; filtration and diffusion
For the following cell type, name one important structural characteristic observed in the laboratory and the function that structure complements or ensures.
sperm
long flagellum; motility
For the following cell type, name one important structural characteristic observed in the laboratory and the function that structure complements or ensures.
smooth muscle
elongated spindle shape; allows contractility
For the following cell type, name one important structural characteristic observed in the laboratory and the function that structure complements or ensures.
red blood cells
small, biconcave shape; allows maneuvering through small blood vessels.
What is the consequence of the red blood cell being anucleate (without a nucleus)?
Red blood cells are unable to reproduce as they lack a nucleus.
Did red blood cells ever have a nucleus? If so, when?
Red blood cells have a nucleus when first made in the red bone marrow. Mature red blood cells have no nucleus.
Of the four cells observed microscopically, which has the smallest diameter? Which has the longest?
sperm (if not including the flagellum) about 5 um. The flagellum is about 50 um. Otherwise, the red blood cell is about 6-8 um.
The longest (if excluding the sperm's flagellum) is the muscle cell, which is 10-50 um.
What is the function of mitotic cell division?
To maintain genetic makeup while creating new cells for growth and repair.
Division of the _______ is referred to as mitosis.
cell
Cytokinesis is the division of the ________.
cytoplasm
The major structural difference between chromatin and chromosomes is that the latter are _________.
condensed/bar-like
Chromosomes attach to the spindle fibers by undivided structures called _______.
centromere
If a cell undergoes mitosis but not cytokinesis, the product is a _____.
binucleate cell
The structure that acts as a scaffolding for chromosomal attachment and movement is called the _____.
spindle
_______ is the period of cell life when the cell is not involved in division.
Interphase
Three cell populations in the body that do not routinely undergo cell division are ______, ______, and ______.
skeletal muscle, cardiac muscle, and neurons
During which cellular phase does the following occur?
Chromatin coils and condenses, forming chromosomes.
prophase
During which cellular phase does the following occur?
The chromosomes are V shaped.
anaphase
During which cellular phase does the following occur?
The nuclear envelope re-forms.
telophase
During which cellular phase does the following occur?
Chromosomes stop moving toward the poles.
telophase
During which cellular phase does the following occur?
Chromosomes line up in the center of the cell.
metaphase
During which cellular phase does the following occur?
The nuclear envelope fragments
prophase
During which cellular phase does the following occur?
The mitotic spindle forms.
prophase
During which cellular phase does the following occur?
DNA replications occurs.
interphase - S
During which cellular phase does the following occur?
Centrioles replicate
interphase - G1
During which cellular phase does the following occur?
Chromosomes first appear to be duplex structures.
prophase
During which cellular phase does the following occur?
Cleavage furrow forms.
telophase
During which cellular phases does the following occur?
The nuclear envelope is completely absent.
metaphase and anaphase.
What is the physical advantage of the chromatin coiling and condensing to form short chromosomes at the onset of mitosis.
It prevents DNA from breaking and tangling during mitosis, which prevents inaccurate replication.