General Biology

1. Duration: 80 min Senior High School Grade: 11 CCSS, NGSS
General Biology 1
Quarter 3 – Module 1

2. Quarter 3 – Module 1:
Cells: The Building
Blocks of Life

3. Objectives
At the end of this module, you are expected to:
1. explain the postulates of the cell theory (STEM_BIO11/12 – Ia – c - 1);
2. describe the structure and function of major and subcellular
organelles (STEM_BIO11/12 – Ia – c – 2).
3. distinguish prokaryotic and eukaryotic cells according to their
distinguishing features (STEM_BIO11/12 – Ia – c 3).

4. Cell: The Building Blocks of Life
The invention of the
microscope led to many advances
in the study of science. By the
1830s many biologists were using
the microscope as their chief
investigation tool. Their
discoveries and breakthroughs
were especially important in
building one of the key theories in
Biology.

5. Zacharias Janssen and Hans were a contributor
on the discovery of the cell. The two are known
for their invention the compound optical
microscope. They invented the microscope in
1590’s. Their invention played a great role in the
discovery of the cell theory, by making it easier
and more practical when observing cells. The
microscope invented by Janssen and Hans was
used by Robert Hooke, the earliest scientist to
study living things under a microscope.

6. Robert Hooke was a British
scientist. In 1665 Hooke made an
important discovery under a
compound optical microscope.
When he looked at a thin slice of
cork under his microscope, he saw
that the cork was made-up of
many tiny units’ room like
structure, he saw tiny little shapes
that looked like little rooms with
walls around each of them. He
named them “cellulae” or simply
“Cell”. This Latin word means "little
rooms”. That was the first
discovery of the cell.

7. In 1674, Anton van
Leeuwenhoek became
the first to observe live
cells. It became possible
for Leeuwenhoek to
observe the cells -living
cells- clearly because of
his invention, the
microscope with
improved lenses that
could magnify objects
from 270 to 300-fold.

8. Matthias Schleiden
was a German botanist. He
found that the plant parts
he examined were made of
cells. Schleiden made the
generalization that all
plants are made of cells.
Theodore Schwann,
a German zoologist, made
a microscopic
investigations of animal
parts that led him to
generalize that all animals
are made of cells.

9. Rudolph Virchow
During the 1850s most people,
including many scientists, thought
that new living things could
spontaneously arise from nonliving
matter. A German biologist, Rudolph
Virchow, disputed the idea of
spontaneous generation. Virchow
reasoned that all living cells come
from preexisting living cells

11. Lesson 2: The Cell Theories

13. The Cell Theory
The cell theory holds some very basic and important claims that are essential to
our concept of life on Earth. According to this theory, the cell serves as the
structural, physiological, systemic, and organizational unit of life. The three
postulates of the cell theory are:

14. 1. All living organisms are
composed of one or more cells
The basic qualification of an
organism is that it must be at least a
single cell, which is a unicellular
organism. Single functioning cells
constitute the bacteria, archaea and
some fungi, thus these are living
things. When several cells compose an
organism, then it is a multicellular
living organism. Plants and animals,
protists and most fungi are
multicellular organisms.

15. 2. The cell is the basic unit of structure and
functioning in organism
The cell carries out the
morphoanatomy and physiology of an
organism. In single- celled organisms, the cell
is everything- the very structure that carries
out all biochemical activities to maintain
cellular life. For multi- cellular organisms, the
whole organism, first begins as one cell.
This first cell undergoes a series of
division to increase the number of cells. These
cells further specialize leading to the
formation of tissues, organs, organ system
and the whole organism. Thus, a bacterium is
one celled while a human being is about 10-
trillion cell of different types.

16. 3. Cells come from pre-existing cells.
For the cell to reproduce,
the requirement is a previously
existing cell. Cells can come
only from cells. Cells cannot
come from anything. A non-
cellular entity cannot produce
a living cell. This statement has
an implication for the
evolution of life here on Earth.
All cells on Earth- past and
present- arose from a single
cell, an inescapable conclusion
assuming no alien intervention

21. What is a cell?

22. What are organelles?
Organelles are the cell structures that perform these specific functions.
In many ways organelles are like machines in a factory, each with a
specific role. The cell has three fundamental parts: the cytoplasm
where the main metabolic life activities take place, the cell membrane
which surrounds the cytoplasm, and the nucleus where the genetic
material is stored.
To further understand the cell as a dynamic miniature factory, compare
the given cell structures to the parts of a big city.

23. • Arch – Cell Membrane and Cell Wall
• Dump site – Lysosome and Peroxisome
• Vehicles – Vacuole
• Factories – Ribosomes
• Municipal hall - Nucleus
• Road and channel – Endoplasmic
Reticulum
• Power line – Mitochondria and
Chloroplast
• Land – Cytoplasm

24. Since you have a little background on cell structures, given on the
next page is a table to provide a framework for other information and
reinforce the theme that structure is correlated with function, cell
organelles have grouped into four categories by general function.

29. What cellular components are shared by bacterial,
animal, and plant cells?

30. Since you have already understood the different organelles found in a cell,
please bear in mind that not all cells are alike. Cells are of many types, each
with distinctive characteristic properties. Bacterial, plant, and animal cells
may be similar in many of their features but due to complexity in structures
and physiological reasons, some organelles are found in animal cells but are
not found in plant and bacterial cells. Below is an activity that you need to do
to understand the similarities of and differences between bacterial, plant, and
animal cells.
Complete the table below to classify cell structures/organelles and cell types
to which they are found.

32. What cellular components are shared by prokaryotic and
eukaryotic cells?
As you have seen the similarities and differences between bacterial,
animal, and plant cells, it only shows that animal and plant cells are
more complex than bacterial cells. Due to structural complexity, many
biologists thought that cells can fall under different classifications for
physiological reasons. A lot of investigations were made until they
conclude that two structurally different cells have existed. Bacteria and
archaea consist of prokaryotic cells, whereas all other forms of life are
composed of eukaryotic cells.
A prokaryotic cell contains nuclear materials not enclosed by a nuclear
membrane (doesn’t have a true nucleus). Eukaryotic cells contain
nuclear materials enclosed by a nuclear membrane (true nucleus)

33. Activity: Cell Analogy
In a faraway city called Light City, the main export and production product is
the steel widget. Everyone in the city has something to do with the steel
widget – making and the entire town is designed to build and export widgets.
The city hall has the instruction for widget making. Widgets come in all shapes
and sizes and any citizen of Light City can get the instructions and begin their
own widgets. Widgets are generally produced in small stores around the city.
These small stores can be built by the construction engineer’s union (whose
headquarters are in city hall). After widgets are constructed, they are placed
on special carts which can deliver the widgets anywhere in the city. In order
for a widget to be exported, the carts take the widget to the postal office,
where the widgets are packaged and labeled for export. Sometimes widgets
don’t turn out right, and the rejects are turned to the scrap yard where they
are broken down for parts or destroyed altogether. The city powers the widget
shops and carts from hydraulic dam. The entire city is enclosed by a large
wooden fence. Only the postal trucks and citizens with proper documents are
allowed inside the city.

34. Match the underlined parts of the city with
the parts of the cell.
__________1. Nucleus
__________2. Mitochondrion
__________3. Cell
__________4. Ribosomes
__________5. Protein
__________6. Golgi apparatus
__________7. Nucleolus
__________8. Lysosomes
__________9. Cell membrane
__________10. Vesicles