cells are the basic building blocks of life, and without them, living things would not
exist. Millions and billions of cells are joined together to make all living things, both
plants and animals. Nearly all cells are very, very tiny and cannot be seen without using
a powerful microscope. Cells have different shapes, colors, designs, and functions.
In addition, every part of every cell has its own function. The three basic parts of all
cells are the nucleus, cytoplasm, and a cell membrane. However, plant and animal cells
are not the same and have some additional parts.
All cells with a nucleus are called eukaryotes and have many structures and
functions in common. Eukaryotes are quite the same in many ways besides containing
the three main parts. All the structures within a cell such as a nucleus and other parts
are called organelles.
However, cells do become specialized depending on their function. For example,
bone cells, liver cells, and nerve cells all develop in ways that enable them to perform
their specific duties. Plants cells too may vary during early stages of growth, but all
contain the same structures.
Plant and animal cells have more common parts than parts that are different. Each
of the parts has a special function, but the shape, size, and location of the cell parts
may vary. Common parts include the nucleus, which is a sphere-shaped body
surrounded by a membrane and contains mostly DNA in chromosomes (genetic
information). It also controls many functions of the cell and might be called the
command center. It regulates various processes in the cell and is in the center of
animal cells but on the edge of plant cells.
Next common part is cytoplasm, a jelly-like fluid which fills the cell in which the
organelles are suspended. It is located outside the cell nucleus and where most
chemical processes take place. The cytoplasm is controlled by enzymes.
The third most common basic part is the cell membrane, which is a thin layer of
protein and fat surrounding the cell. The cell membrane controls the movement of
substances into and out of the cell, as some substances are permitted to pass through,
while others are blocked. Other common parts of plant and animal cells include
mitochondria, ribosomes, and vacuoles.
Plant cells have two functions which are not required of animal cells. One of them
is photosynthesis, a process plants use to produce their own food. The second
function of cells is supporting its own weight, which most animals do by means of a
skeleton. A cell wall is found only in plant cells and it includes a layer of cellulose fiber
for its support and structure. It is found on the outside of the membrane and
strengthens the cell, works in combination with the plant vacuole, and helps the cell
maintain its shape and rigidity.
Chloroplasts are found only in plant cells which contain chlorophyll giving a plant its
green color. It is the location for the process of photosynthesis where energy from the
sun is converted into energy. It is one of several other plastids used to convert
sunlight, carbon dioxide, and water into food.
Finally, centrioles are found only in animal cells and help move chromosomes
during cell division and are only visible when the animal cell is dividing. They also
ensure that chromosomes are in the proper location during cell division
Besides some different parts, a plant cell is usually larger and rectangular or
squarish in shape. On the other hand, most animal cells are roundish or irregular in
shape. Scientists believe that an early point in the evolution of life on Earth, plants, and
animals once shared a common ancestor. It is the reason plants and animal cells are so
much alike, meaning all life on Earth is related.
1) All the following are parts of plant and animal cells EXCEPT:
A: Cell wall
B: Nucleus
C: Cell membrane
D: Cytoplasm
2) Which part of a cell contains chromosomes?
A: Cytoplasm
B: Cell wall
C: Nucleus
D: Vacuoles
3) Which of the following cell part is found only in plants cells?
A: Cell membrane
B: Centriole
C: Organelles
D: Cell wall
4) Which of the following cell part is found only in animal cells?
A: Cell membrane
B: Centriole
C: Organelles
D: Cell wall
5) Which of the following gives plants their green color?
A: Cytoplasm
B: Chlorophyll
C: Plastids
D: Chromosomes
6) The DNA of a plant or animal cell is found in which of the following parts of a cell?
A: Chromosomes
B: Chloroplasts
C: Chlorophyll
D: Cell wall