Chapter 4 Flashcards
is the structural and functional unit of all living things
cell
contains genetic material, DNA, sections of which are called genes
nucleus
the control center of the cell, is necessary for cell reproduction
nucleus
genetic material that is loosely dispersed throughout the nucleus in a threadlike form
chromatin
chromatin that has coiled and condensed forming dense, rodlike bodies
chromosomes
small spherical bodies within the nucleus composed primarily of proteins and RNA
nucleoli
assembly sites for ribosomes that are particularly abundant in the cytoplasm
nucleoli
surrounds the nucleus; is double layered porous membrane
nuclear envelope
the nuclear envelope has large ___ ____ that regulate what passes through
nuclear pores
separates the cell contents from the surrounding environment, providing a protective barrier
plasma membrane
membrane that is a bilayer of phospholipid molecules in which the protein molecules float
plasma membrane
the plasma membrane is selective about what passes through it, this is known as
selective permeability
tiny fingerlike projections/folds
microvilli
organelles translates to
small organs
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
endoplasmic reticulum
studded with ribosomes, tubules of this organelle provide area for storage and transport of the proteins made on the ribosomes to other cell areas
rough ER
no function of protein synthesis, is the site of steroid and lipid synthesis, lipid metabolism, and drug detoxification
smooth ER
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 to export from the cell or incorporation into the plasma membrane and in packaging lysosomal enzymes
golgi apparatus
membranous sacs containing digestive enzymes including acid and hydrolyses; function is to digest worn-out cell organelles and foreign substances that enter the cell
lysosomes
membranous sacs containing oxidase enzymes that detoxify alcohol, free radicals, and other harmful chemical
peroxisomes
rod-shaped bodies with double membrane wall; contains enzymes that oxidize foodstuffs to produce ATP; powerhouse of the cell
mitochondria
paired, cylindrical bodies composed of microtubules and are part of the centrosome; they direct the formation of the mitotic spindle during cell division
centrioles
internal scaffolding that provides cellular support and functions in intracellular transport
cytoskeleton
formed largely of actin, a contractile protein, and are important in cell mobility
microfilaments
stable elements composed of a variety of proteins and resist mechanical forces action on cells
intermediate filaments
form the internal structure of the centrioles and help determine cell shape
microtubules
longer period during which the cell grows and carries out its usual activities
interphase
the period when the cell reproduces itself by dividing
cell division or mitotic phase
during this phase, the cell is about to divide and the DNA is copied exactly
interphase
is essential for growth and repair
cell division
consists of two events, mitosis and cytokinesis
M phase ; mitosis
is the division of the copied DNA of the mother cell to two daughter nuclei
mitosis
is the division of the cytoplasm
cytokinesis
the product of mitosis is two ____ _____ that are genetically identical to the m other nucleus
daughter nuclei
yields four daughter nuclei that differ genetically in composition from the mother nucleus; used for sexual reproduction
meiosis
part of interphase where the centrioles begin replicating
G1
part of interphase when DNA is replicated
S phase
final part of interphase where final preparations for mitosis are completed and centrioles finish replicating
G2
is the first phase of mitosis
prophase
chromatin condenses forming chromosomes; the nucleoli disappear, centrosomes separate from one another
early prophase
centrosomes act as a focal point for growth of a microtubule assembly called the
mitotic spindle
microtubules lengthen and, they propel the centrosomes towards opposite poles of the cell
early prophase
microtubules arrays extend from the centrosome matrix
asters
the nuclear envelope breaks up; the kinetochore microtubules pull on each chromosome from the poles and ultimately draws the chromosomes to the center
late prophase
the second phase of mitosis
metaphase
phase where the chromosomes cluster at the midline of the cell with centromeres aligned at the equator
metaphase
the third and shortest phase of mitosis
anaphase
the sister chromatids separate from each other and are pulled towards opposite ends of the cell. The protein “glue” that holds the sister chromatids together is broken down, allowing them to separate. Each is now its own chromosome. The chromosomes of each pair are pulled towards opposite ends of the cell.
anaphase
the final phase of mitosis
telophase
the process that separates the duplicated genetic material carried in the nucleus of a parent cell into two identical daughter cells. During telophase, a nuclear membrane forms around each set of chromosomes to separate the nuclear DNA from the cytoplasm.
telophase
the cytoplasmic division of a cell at the end of mitosis or meiosis, bringing about the separation into two daughter cells.; forms the cleavage furrow and pinches the cell apart
cytokinesis
