Chapter 2: From A Cell to an Organism
Lesson 2.1- The Cell Cycle and Cell Division
A. The
is the life cycle of the cell.
1.
of the cell cycle include interphase, mitosis, and
cytokinesis.
a.
is when a cell is preparing to reproduce.
b. During the mitotic phase, the nucleus and cytoplasm divide
producing two new cells.
2. The
of a cell cycle differs for different organisms
and cells.
3. A cell performs specific
during interphase.
a. (Each pair of similar chromosomes are called
_______________ chromosomes.)
b. Homologous chromosomes are similar but not identical.
c. (Humans have ______ pairs of homologous chromosomes in
each human cell).
d.
consists of 3 phases: G1,S, and G2.
e. In
the cell grows and carries out normal, cellular
functions.
f. Some cells such as muscle, nerve, and red blood cells, stay in
G1 and never
.
g. In S phase, the
chromosome pairs in the
cell’s nucleus replicate.
h. The copies of the chromosomes made during S phase are
_________________________.
i. The sister chromatids are held together in the region near
the middle of each chromatid called the
.
j. The replication ensures that the new cells formed are
______________.
k. In
phase, the cell grows and functions, and some
_____________replicate.
B.
is the process by which the nucleus divides;
_________________is the process by which the cytoplasm divides.
1. Mitosis and cell
ensure that each new cell receives all it
needs to function.
a. Mitosis and cell division
old worn-out cells, and are
the method of reproduction for some organisms.
b. Mitosis and cell division produce most cells in a
_____________________organism.
c. A different type of cell division produces
and
____________cells.
2. There are
phases of mitosis in order: prophase,
metaphase, anaphase, and telophase.
a. In
, DNA in chromosomes twists into tight
coils and the nucleus breaks apart.
b. In
, the chromosomes move to the
middle of the cell and pairs of sister chromatids line up.
c. In
, fibers attached to the
of
the sister chromatids pull them apart toward opposite ends
of the cell. The chromatids are then called chromosomes.
d. In
, a new membrane forms around each
set of chromosomes, creating two identical nuclei, and
chromosomes become less tightly coiled.
3.
is the final stage of cell division.
a. During cytokinesis, the cytoplasm and its contents divide to form
two identical cells called
.
b. At the start of cytokinesis, the cell membrane
inward.
c. In a cell with a cell wall, a
forms between the
two new nuclei.
d. The cell plate later becomes the cell
, which builds
the new cell walls.
4. Cell division results in
new daughter cells to replace the
original parent cell.
a. After mitosis and cell division, the original cell—called the
______________cell—no longer exists.
b. The daughter cells’ chromosomes are identical to the parent cell’s in
_____________ and type.
c. Because of mitosis and cytokinesis, all the cells in your body, except
sperm and
cells, have identical chromosomes.
Lesson 2.2- Levels of Organization
A. A
organism carries out all the functions it needs to
survive.
1. Prokaryotes, such as
, do not have a nucleus or
membrane-bound organelles.
a. Bacteria have
with specific functions.
b. Some processes that occur in
in eukaryotes
happen along specialized membranes in prokaryotes.
2. Each one-celled
has a nucleus and organelles with
specialized functions.
a. One-celled eukaryotes include
and some fungi.
b. One-celled eukaryotes are more complex than cells in
_________________eukaryotes because they are self-sufficient.
c. Cells in many-celled organisms
on other cells to
perform different functions.
d. Some protists, including Volvox, live and function in
with
specialized cells.
B. Many-celled organisms have many cells and usually have more than one
type of cell.
1. Cell
is the process by which cells become different
types of cells.
a. Even though all cells in an organism have
sets of
chromosomes, cells are able to differentiate by using
___________________ parts of the instructions on the
chromosomes.
2.
3.
4.
5.
b. Differentiated cells often have
structures and
shapes to perform specific functions.
c. Liver cells have
ER (endoplasmic reticulum) for filtering
blood;
cells are highly branched for sending and
receiving signals.
d. Once most human cells
, they cannot become
any other cell type.
e.
are undifferentiated; they can become different types
of cells.
f. Some
cells can differentiate into another type of cell
after they have differentiated into one type.
A
is a group of cells, such as muscle fiber, that works
together to perform a function.
An
is a group of similar tissues that work together to
perform a function.
a. Examples of human
are the heart, lungs, brain,
stomach, and muscles.
b.
have organs that store nutrients, transport
substances, provide protection, and perform
.
c. A leaf is an example of a plant organ.
An
is one or more organs working together to
perform one or more functions.
a. The muscular, digestive, and skeletal systems are examples of organ
________________.
b. The
sends and receives signals to coordinate the organ
systems in the body.
The many-celled
is the most complex unit of living
things.
a. Each organ system has its own
but depends on other
organ systems.
b. The correct sequence, from least to most complex, is cell, tissue,
_______________, organ system.