Lesson Plan in People and Earth Ecosystem

Topic CARBON CYCLE

Reporters BAUTISTA, RONALD REY
MACINAS, JHONA
MILLENA, HEART FAYE
Year and Block III-SCIENCE- A
Time Allotment
I. OBJECTIVES
At the end of the lesson the student should be able to;
A. Objectives a. Define the carbon cycle and its major processes.
b. Identify the different reservoirs of carbon on Earth.
c. Describe how human activities impact the carbon cycle
d. Explain the Importance of the carbon cycle for life on earth.
II. CONTENT
●Carbon is a fundamental building block of life and is constantly moving
around Earth in a cycle.
●The carbon cycle involves processes like photosynthesis, cellular
respiration, decomposition, and fossil fuel burning.
●Carbon is stored in reservoirs like the atmosphere, oceans, biosphere, and
geosphere.
●Human activities like deforestation and burning fossil fuels disrupt the
natural balance of the carbon cycle.
III. LEARNING
RESOURCES
A. References https://www.khanacademy.org/science/biology/ecology/biogeoche
mical-cycles/a/the-carbon-cycle

IV. PROCEDURE MATERIAL

S
A. Engage ●Show students a variety of objects like a plant, a piece of wood, Plastic
and a plastic bottle. Ask them what they have in common (all Bottle
contain carbon). Plant
●Ask them if they think carbon stays in one place forever. Pieceof
Introduce the concept of the carbon cycle. woode
B. Explore ●Now, we will divide you into 4 groups, and we will give you a Group
different reservoir of carbon (atmosphere, oceans, biosphere, Presentation
geosphere)
●As a group, research the assigned reservoir to your group and
create a short presentation sharing interesting facts and images.
●As a group, discuss the different reservoirs and how they
connect.
C. Explain What is Carbon?

Carbon is part of our bodies, but it's also part of our modern-day
industries. Carbon compounds from long-ago plants and algae
make up the fossil fuels, such as coal and natural gas, that we use
today as energy sources. When these fossil fuels are burned,
carbon dioxide (CO2) is released into the air, leading to higher and
higher levels of atmospheric CO2. This increase in CO2 levels
affects Earth's climate and is a major environmental concern
worldwide.

Carbon Cycle

The carbon cycle is the process by which carbon moves through

Earth's living and nonliving parts. It includes:
Biological processes, such as photosynthesis and cellular
respiration.

Geological processes, such as the formation of fossil fuels and the

weathering of rocks.

- The carbon cycle is also the process by which carbon moves

through Earth's living and nonliving parts.

The carbon cycle is most easily studied as two interconnected

subcycles:
● One dealing with rapid carbon exchange among living
organisms.
● One dealing with long term cycling of carbon through geologic
processes.

Carbon exists in the air largely as carbon dioxide—CO2—gas,

which dissolves in water and reacts with water molecules to
produce bicarbonate—HCO3. Photosynthesis by land plants,
bacteria, and algae converts carbon dioxide or bicarbonate into
organic molecules. Organic molecules made by photosynthesizers
are passed through food chains, and cellular respiration converts
the organic carbon back into carbon dioxide gas.

Longterm storage of organic carbon occurs when matter from

living organisms is buried deep underground or sinks to the bottom
of the ocean and forms sedimentary rock. Volcanic activity and,
more recently, human burning of fossil fuels bring this stored
carbon back into the carbon cycle. Although the formation of fossil
fuels happens on a slow, geologic timescale, human release of the
carbon they contain—as CO2—is on a very fast timescale.

The Biological Carbon Cycle

Carbon enters all food webs, both terrestrial and aquatic, through
autotrophs, or self-feeders. Almost all of these autotrophs are
photosynthesizers, such as plants or algae.

Autotrophs capture carbon dioxide from the air or bicarbonate ions

from the water and use them to make organic compounds such as
glucose. Heterotrophs, or other-feeders, such as humans,
consume the organic molecules, and the organic carbon is passed
through food chains and webs.

The Geological Carbon Cycle

The geological pathway of the carbon cycle takes much longer

than the biological pathway described above. In fact, it usually
takes millions of years for carbon to cycle through the geological
pathway. Carbon may be stored for long periods of time in the
atmosphere, bodies of liquid water—mostly oceans— ocean
sediment, soil, rocks, fossil fuels, and Earth’s interior.

The level of carbon dioxide in the atmosphere is influenced by the

reservoir of carbon in the oceans and vice versa. Carbon dioxide
from the atmosphere dissolves in water and reacts with water
molecules in the following reactions:

CO2 + H2O <=> H2CO3<=> HCO3- + H+ <=> CO^2- 3 +H+ <=>

CO^2- 3 + 2H+

The carbonate—CO^2- 3—released in this process combines with

ions to make calcium carbonate—CaCO3—a key component of
the shells of marine organisms.When the organisms die, their
remains may sink and eventually become part of the sediment on
the ocean floor. Over geologic time, the sediment turns into
limestone, which is the largest carbon reservoir on Earth.

On land, carbon is stored in soil as organic carbon from the

decomposition of living organisms or as inorganic carbon from
weathering of terrestrial rock and minerals. Deeper under the
ground are fossil fuels such as oil, coal, and natural gas, which are
the remains of plants decomposed under anaerobic—oxygen-
free—conditions. Fossil fuels take millions of years to form. When
humans burn them, carbon is released into the atmosphere as
carbon dioxide.
Another way for carbon to enter the atmosphere is by the eruption
of volcanoes. Carbon-containing sediments in the ocean floor are
taken deep within the Earth in a process called subduction, in
which one tectonic plate moves under another. This process forms
carbon dioxide, which can be released into the atmosphere by
volcanic eruptions or hydrothermal vents.

Major Processes of Carbon Cycle

Photosynthesis: Plants and other organisms capture carbon

dioxide from the atmosphere and use it to create organic
molecules.

Cellular respiration: Organisms break down organic molecules and

release carbon dioxide back into the atmosphere.
 Decomposition: Decomposers break down dead organisms and
waste products, releasing carbon dioxide back into the
atmosphere.

Geologic processes: Carbon dioxide is absorbed by the ocean and

slowly converted into rocks and fossil fuels over millions of years.
These processes can also release carbon dioxide back into the
atmosphere through volcanic eruptions and weathering.

Different Reservoirs of Carbon on Earth

The different reservoirs of carbon on Earth include the

atmosphere, oceans, soil, rocks, fossil fuels, and living organisms.
The largest reservoir is the ocean, followed by rocks.
D. Elaborate HUMAN ACTIVITIES THAT IMPACT CARBON CYCLE

Burning fossil fuels releases carbon dioxide into the atmosphere,

which contributes to the greenhouse effect and global warming.

Deforestation reduces the amount of carbon dioxide that is

removed from the atmosphere by plants through photosynthesis.
 The use of fossil fuels and deforestation also release other
greenhouse gases, such as methane and nitrous oxide, into the
atmosphere.

These human activities have led to a significant increase in the

amount of carbon dioxide in the atmosphere, which is causing a
variety of problems, including rising sea levels, more extreme
weather events, and changes in plant and animal life.

Why is the Carbon Cycle Important for Life on Earth?

●Provides carbon, a building block of life, for living organisms

●Stores and releases carbon dioxide, a gas necessary for plant
growth
●Regulates Earth's climate
●Maintains the pH of the ocean
E. Evaluate ● Write down one Key take away from the lesson Evaluation
● 10 item multiple choice test will be given to the students Sheet

Prepared by:

BAUTISTA, RONALD REY

MACINAS, JHONA
MILLENA, HEART FAYE

Noted by:

JOSAN S. NEBRES, MABioEd

Instructor

Name: _______________________ Yr. Level &

Section:_________________________ Score:________

Directions: Multiple Choice. Read the questions carefully. Encircle the correct answer.

1. What is the primary source of carbon in the carbon cycle?

a) Atmosphere
b) Plants
c) Soil
d) Oceans

2. Which process in the carbon cycle converts atmospheric carbon dioxide into organic
compounds?
a) Photosynthesis
b) Respiration
c) Decomposition
d) Combustion

3. What happens to carbon when fossil fuels are burned?

a) It is released into the atmosphere as carbon dioxide
b) It is converted into organic compounds
c) It is stored in the soil
d) It is absorbed by plants

4. How do plants obtain carbon dioxide for photosynthesis?

a) Through the roots
b) Through the leaves
c) Through the stems
d) Through the flowers

5. Which process in the carbon cycle releases carbon dioxide into the atmosphere?
a) Photosynthesis
b) Respiration
c) Decomposition
d) Combustion

6. What is the main role of decomposers in the carbon cycle?

a) Absorb carbon dioxide from the atmosphere
b) Convert organic matter into carbon dioxide
c) Store carbon in the soil
d) Release carbon dioxide into the atmosphere

7. How does carbon return to the atmosphere from the oceans?

a) Through volcanic eruptions
b) Through ocean currents
c) Through evaporation
d) Through photosynthesis

8. What is the process by which carbon is transferred from living organisms to the soil?
a) Decomposition
b) Photosynthesis
c) Respiration
d) Combustion

9. What is the primary greenhouse gas associated with the carbon cycle?
a) Carbon dioxide
b) Methane
c) Nitrous oxide
d) Ozone

10. How does deforestation impact the carbon cycle?

a) It decreases the amount of carbon dioxide in the atmosphere
b) It increases the amount of carbon dioxide in the atmosphere
c) It has no effect on the carbon cycle
d) It increases the amount of carbon stored in the soil

Answer Key:

1. b) Plants
2. a) Photosynthesis
3. a) It is released into the atmosphere as carbon dioxide
4. b) Through the leaves
5. b) Respiration
6. b) Convert organic matter into carbon dioxide
7. a) Through volcanic eruptions
8. a) Decomposition
9. a) Carbon dioxide
10. b) It increases the amount of carbon dioxide in the atmosphere