Completion
Complete each sentence or
statement.
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1.
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Cells
carry on the many functions needed to sustain life. In order to do this, they must be able to take in
nutrients, which cells use to provide energy for the work that they do. They must also be able to
release wastes.
One way that materials enter and leave a cell is
through ____________.
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2.
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_____________ is the movement of particles from an area where their concentration is
____ to an area where their concentration is ___.
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3.
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Particles travel from areas where they are crowded to areas where they are less
crowded. Because this is the natural movement of particles, _______________ does not require the cell
to expend __________.
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4.
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One
of the most important substances that passes through the cell membrane is _____.
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5.
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Water
passes through the cell membrane by a type of diffusion know as ____________.
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6.
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During osmosis, water molecules move from a place of ______ concentration to a place
of _______ concentration -- either _____ or _____ of the cell.
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Other
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7.
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Review the concepts by studying the following picture.
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8.
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Another process that cells must carry out is the production of more cells. The total
number of cells must increase in order for an organism to grow.
The process through which a cell forms new cells is known as the
_____ ________.
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9.
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The
_____ ______ begins when a cell is formed and ends when the cell divides to form new
cells.
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10.
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What
would happen if a cell simply divided into two cells?
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11.
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How
does a cell ensure that each new cell has all of the necessary genetic information?
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12.
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After
the genetic information is copied, the actual process of cell division depends on the _____ of cell
involved.
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13.
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In
prokaryotic cells, cell division is relatively _________.
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14.
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A
prokaryotic cell uses a process know as binary fission.
What is binary
fission?
Name an organism that uses this type of cell division.
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15.
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In
eukaryotic cells, the cell cycle is more complex. There are five main
stages.
Interphase: (The Growing Phase) The cell grows and carries out
routine functions.
S Phase of Interphase: The cell's chromosomes are
copied.
Notice that the
original chromosome and its duplicate are still linked. These identical chromosomes are now called
sister chromatids (each individual structure is called a
chromatid).
The chromatids
are held together by a round structure called a centromere. Although the chromosomes have been
duplicated, they are still considered a single unit.
Remember:
• Cell division consists of three
things: interphase, mitosis, and cytokinesis.
• During the S stage of interphase, the chromosomes
replicate..
• Growth occurs during the G1 and G2
stages of interphase
Once the chromosomes have replicated, the cell is
ready to begin mitosis. Mitosis is the period when the cell divides. Mitosis consists of a sequence
of four stages:
Prophase
Metaphase
Anaphase
Telophase
The following
are diagrams of the four stages. They may, or may not, be in order.
Using the
numbers by each diagram, arrange the stages in the correct order and include the name of each
stage.
1.  2.
3.  4.
The last stage
of the cycle is Cytokinesis where the two daughter cells are completely separated. Remember:
In plants Cytokinesis occurs differently than in animals cells. The cell doesn't form a
cleavage furrow. Instead a partition called a cell plate forms down the middle
region.
Once the
daughter cells are produced, they reenter the initial phase -- interphase -- and the whole process
starts over. The cell goes back to its original state. Once again, the chromosomes become invisible,
and the genetic material is called chromatin.
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16.
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Mitosis has two purposes. What are they?
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17.
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Reproduction is the process through which organisms produce
offspring.
There are two types of reproduction. Name them.
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18.
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Reproduction in which only one parent cell is required is called
______ ______________.
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19.
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Binary fission is an example of __________
_____________.
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20.
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Reproduction in which two parent cells join together to form a new individual is
called
__________ _____________.
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21.
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How
are sex cells different than all other types of body cells?
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22.
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Sex
cells are produced during a process known as ___________.
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23.
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Meiosis is a form of cell division that cuts the number of chromosomes in
_____.
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24.
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When
sex cells are formed, the chromosomes are copied once, but then the nucleus divides ________ so
that the resulting four cells have half the number of chromosomes found in a normal body
cell.
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25.
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A
cell must also break down food so that energy stored in the food can be used.
When this process takes place in the presence of oxygen, it is called __________
___________.
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26.
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During cellular respiration, food (glucose) is broken down into _______
_________ and _________. Energy is released in the process. Some of this energy is stored as ______,
which supplies energy to fuel the cell's activities. Much of the energy is released as
____.
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27.
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Compare and contrast mitosis with meiosis.
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28.
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A
process that requires oxygen is described as __________.
A process that
does not require oxygen is described as ____________.
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