Q2-Quarter 1 Earth and Life Science Grade

Earth and Life Science, Grade-11

1. Evolving Concept
of Life
Ela Jane S. Vargas, LPT
Quarter 2, Lesson 1

2. Today, let’s talk about Life:
ORIGIN AND
FORMS OF LIFE
THEORIES ON
THE ORIGIN OF
LIFE
UNIFYING
THEMES IN THE
STUDY OF LIFE

3. Life on Earth was believed to have started at least
3.5 to 4 billion years ago.

4. The first evidence of life was found in microfossils…
type of fossil that contain the
remains of tiny plants and
animals
can only be seen through the
microscope

5. Organisms found in microfossils are prokaryotes
do not contain nucleus
known to be the earliest form of
life
to adapt to its environment,
they started to produce their
own food by photosynthesis
referred as photosynthetic
organisms
first photosynthetic organism
was the cyanobacteriawhich is
one of the easiest microfossils to
recognize.

6. Photosynthesisgreatly helped change the Earth’s
atmosphere
Its production of oxygen which then
allowed oxygen-breathing organisms to
thrive.

7. Organisms that have membrane bound nucleus
and organelles are called eukaryotes
After some time, microfossils that
showed remains of organisms having a
different structure compared to the first
forms were identified which was about
1.5 billion years old.
These organisms are larger than
bacteria and have internal membranes
and thicker walls.

8. There was an increase in diversity and number of
complex animals that thrived and was referred as the
Cambrian period.

9. This eventually led into the reign of dinosaursthat was
said to have reached every continent on Earth.
Due to events that
happened on the
planet, these
organisms faced
extinction

10. About 200,000 years ago, Homo sapiens lived on
Earth until this very day.

11. Timeline of the History of Life on Earth

12. Today, let’s talk about Life:
ORIGIN AND
FORMS OF LIFE
THEORIES ON
THE ORIGIN OF
LIFE
UNIFYING
THEMES IN THE
STUDY OF LIFE

13. 1. Spontaneous Generation Theory
In the ancient times,
people usually explain
things based on what
they see without using
any equipment.
They believed that life
originated as a
spontaneous event and
living organisms
develop from nonliving
matter.

14. 2. Biogenetic Theory
This theory believed that
life produced life.
This have been proven
after the advancement
of technology and
microscopes were
invented.
The reproduction
process was studied
well like how a zygote
forms after the egg cell
and sperm cell unites.

15. 3. AbiogeneticSynthesis Theory by Alexander Oparin
This theory states that life came
from organic chemicals and
processes.
From the first elements, carbon,
hydrogen, oxygen, nitrogen,
and sulfur, molecules were
formed that developed
complex compounds.
Proteins, carbohydrates, and
other compounds developed
and turned the sea into a
primordial soup that allowed
the formation of cells.

16. Theory of Evolution through Natural Selection
by Charles Darwin
In this theory, organisms are
said to produce offspring that
are able to survive in the
environment.
Since nature has limited
resources, organisms having
traits that favor survival prevails
which then leads to a well-
adapted population.
Basically, this theory talks about
the survival of the fittest
because the fittest organisms
lives on until the next
generation.

17. IRRITABILITY
Characteristics of a Living Organism
ability of an organism to react to a stimulus
such as temperature, pressure, tension, and
chemicals
1
LOCOMOTION2 ability of an organism to move (For microscopic
organisms, locomotion is done through structures
such as cilia and flagella.)
METABOLISM3 refers to all the chemical processes that builds
up or break down materials.

18. GROWTH
Characteristics of a Living Organism
can be observed through the increase in size.
(Growth of organisms can also be seen in the
microscopic level wherein the cells divides and increases
in number. )
4
REPRODUCTION5
ability of an organism to produce its offspring that
resembles them
CELLULAR
ORGANIZATION
6
refers to the parts and functions of the cell
which is the basic unit of life.
(Some organisms may contain one cell which is called
unicellular where all functions are being carried out while
some may contain many cells which is called
multicellular that has specific functions.)

19. Today, let’s talk about Life:
ORIGIN AND
FORMS OF LIFE
THEORIES ON
THE ORIGIN OF
LIFE
UNIFYING
THEMES IN THE
STUDY OF LIFE

20. Biological Systems1
All levels of life have systems of
related parts.
A system is an organized
group of related parts that
interact with each other to
form a whole.
In all scales of biology, from
the microscopic molecules up
until the biosphere, a system
exists.

21. Cellular Basis of Life2
All living things are made up of
cells which is the basic unit of
life.
It is the one that performs all
activities needed for life.
All cells share certain
characteristics such as having
an enclosed membrane that
regulates the exchange of
materials between the cell
and its surrounding entity.

22. Cellular Basis of Life2
There are two main form of
cells, prokaryotic and
eukaryotic.
Prokaryoticorganismsinclude
single-celled organisms such
as bacteriaand archaea.
Eukaryoticorganismsare all
other forms of life such as
plants and animals.

23. Structure and Function3
Functions of an organism is
directly related to its shape or
form like how different cells
have specific components
that allows them to carry out
their functions in the body.
Example: A red blood cell
which carries oxygen are
formed differently than a
white blood cell which fights
infection.

24. Structure and Function3
In humans, each type of teeth
functions differently.
The sharp front teeth allow
biting of food while the molar
teethare the ones the grinds it
into smaller pieces.

25. Reproduction and Inheritance4
Each species must be able to
reproduce and pass on
genetic materials that
contains the information that
determines the inherited
characteristics.
Chromosomeswhich is found
within the cell is the one that
contains this genetic material
in the form of
Deoxyribonucleic Acid (DNA).

26. Reproduction and Inheritance4
A DNA molecule contains
hundreds or thousands of
genes which are the units
of inheritance.
It encodes the information
required to carry out all
bodily functions and
development.

27. Evolution5
It is the core theme in the study of life.
It is the one that explains the unity
and diversity of life.
Evolution explains how changes
occurred in organisms over time.
The concept of evolution connects
observations from cells up into the
biosphere.
Evolution also includes adaptation
wherein organisms have obtained
beneficial characteristics in response
to their environment.

28. Today, we just learned the
Evolving Concept of Life.
ORIGIN AND
FORMS OF LIFE
THEORIES ON
THE ORIGIN OF
LIFE
UNIFYING
THEMES IN THE
STUDY OF LIFE

29. Any question?

30. Evolving Concept
of Life
Ela Jane S. Vargas, LPT