the structural and functional unit of all living things
cell
the three major parts of all animal cells
nucleus
plasma membrane
cytoplasm
the nucleus contains genetic material called ____
DNA
sections of DNA are called _____
genes
the ______ is necessary for cell reproduction
nucleus
a cell that has lost its nucleus can no longer ______
divide
when the cell is not dividing, the genetic material is loosely
dispersed throughout the nucleus in a threadlike form called _______
chromatin
when the cell is in the process of dividing to form daughter cells,
the chromatin coils and condenses forming dense rode like bodies
called _____
chromosomes
the nucleus also contains one or more small spherical bodies called ______
nucleoli
nucleoli composed primarily of _________ and ___________
proteins
RNA
the nucleus is bound by a double-layered porous membrane called the ________
nuclear envelope
the main structural building blocks of the plasma membrane are ______
and _______
phospholipids
globular protein moelcules
Tiny spherical bodies composed of RNA and protein; floating free or
attached to a membranous structure (the rough ER) in the cytoplasm.
Actual sites of protein synthesis.
ribosomes
Membranous system of tubules that extends throughout the cytoplasm;
two varieties: rough and smooth. Rough ER is studded with ribosomes;
tubules of the rough ER provide an area for storage and transport of
the proteins made on the ribosomes to other cell areas.
endoplasmic reticulum
___________ which has no function in protein synthesis, is a site of
steroid and lipid synthesis, lipid metabolism, and drug detoxification.
smooth endoplasmic reticulum
Stack of flattened sacs with bulbous ends and associated small
vesicles; found close to the nucleus.
golgi apparatus
Plays a role in packaging proteins or other substances for export
from the cell or incorporation into the plasma membrane and in
packaging lysosomal enzymes.
golgi apparatus
Various-sized membranous sacs containing digestive enzymes including
acid hydrolases; function to digest worn-out cell organelles and
foreign substances that enter the cell. Have the capacity of total
cell destruction if ruptured and are for this reason referred to as
�suicide sacs.�
lysosomes
Small lysosome-like membranous sacs containing oxidase enzymes that
detoxify alcohol, free radicals, and other harmful chemicals. They are
particularly abundant in liver and kidney cells.
perioxosomes
Early Prophase
As the chromosomes appear, the _______ disappear, and the two
centrosomes _______ from one another.
nucleoli
separate
Paired, cylindrical bodies that lie at right angles to each other,
close to the nucleus.
centrioles
As part of the centrosome, these organelles direct the formation of
the mitotic spindle during cell division; form the bases of cilia and
flagella and in that role are called basal bodies.
centrioles
two stages of cell life cycle
interphase
cell division
the longer period during which the cell grows and carries out its
usual activities
interphase
when the cell reproduces itself by dividing.
cell division
In an interphase cell about to divide, the genetic material (DNA) is
copied exactly via __________.
DNA replication
_________ is the division of the copied DNA of the mother cell to two
daughter nuclei.
mitosis
___________ is the division of the cytoplasm, which begins when
mitosis is nearly complete.
cytokinesis
The product of ______ is two daughter nuclei that are genetically
identical to the mother nucleus.
mitosis
a specialized type of nuclear division that occurs only in the
reproductive organs (testes or ovaries)
meiosis
_______ which yields four daughter nuclei that differ genetically in
composition from the mother nucleus, is used only for the production
of gametes (eggs and sperm) for sexual reproduction.
meiosis
The function of cell division, including ________ and _________ in
the body, is to increase the number of cells for growth and repair.
mitosis
cytokinesis
the phases of mitosis
prophase
metaphase
anaphase
telophase
Interphase
Early Prophase
Late Prophase.
_____phase is not a part of mitosis.
Interphase
During Interphase, the DNA-containing material is in the form of
_________. The _________ and one or more nucleoli are intact and visible.
chromatin
nuclear envelope
The three distinct periods of interphase:
G1
S phase
G2
The three distinct periods of interphase:
the centrioles begin replicating
(adding cytoplasm, cell getting bigger)
G1
The three distinct periods of interphase:
DNA is replicated
(growth and DNA synthesis)
S Phase
The three distinct periods of interphase:
Final preparations for mitosis are complicated, and centrioles
finish replicating
(make copies of all needed organelles; lysosomes, golgi body, etc.)
G2
Early Prophase
The chromatin condenses, forming barlike _____________
chromosomes
Early Prophase
Each duplicated chromosomes consists of two identical threads,
called ___________ held together at the ____________.
sister chromatids
centromere
Early Prophase
As the chromosomes appear, the _______ disappear, and the two
centrosomes _______ from one another.
nucleoi
separate
Early Prophase
The centrosomes act as focal points for growth of a microtubule
assembly called the _________-.
mitotic spindle
Late Prophase
The ___________ breaks up, allowing the spindle to interact with the chromosomes.
nuclear envelope
Late Prophase
Some of the growing spindle microtubules attach to _______, special
protein structures at each chromosome's centromeres. These are called ______.
kinetochores
kinetochore microtubules
Late Prophase
The remaining spindle microtubules (not attached to any chromosomes)
are called _________. The microtubules slide past each other, forcing
the poles apart.
polar microtubules
Second phase of mitosis starts here.
Metaphase
Metaphase
The chromosomes cluster at the midline of the cell, with their
centromeres, precisely aligned at the ______ of the spindle.
metaphase plate
Metaphase
Enzymes act to _______ the chromatids from each other.
seperate
Third phase of mitosis:
anaphase
The shortest phase of mitosis
anaphase
Anaphase
Begins abruptly as the centromeres of the chromosomes ___
simultaneously. Each chromatid now becomes a ________ in its own right.
split
chromosome
Anaphase
The moving chromosomes look ___ shaped. The _________ lead the way,
and the chromosomal "arms" dangle behind them.
V shaped
centromeres
the final phase of mitosis
telophase
Telophase
Telophase begins as soon as chromosomal movement stops. The final
phase is like __________ in reverse.
prophase
Telophase
The identical sets of chromosomes at the opposite poles of the cell
uncoiled and resume their threadlike ________ form.
chromatin
Telophase
A new _____________ forms around each chromatin mass, nucleoli
reappear within the nuclei, and the spindle breaks down and disappears.
nuclear envelope
Telophase
Mitosis is now ended. The cell, for just a brief period, is
____________ and each nucleus is identical to the original parent nucleus.
binucleate
division of the cytoplasm
cytokinesis
Cytokinesis begins in late _________ and continues through and beyond ____________.
anaphase
telophase
A contractile ring of actin microfilaments from the ________________
and pinches the cell apart.
cleavage furrow