Download ACTIVITy-2 - CBSE

CONTENTS
1.
Introduction
1
2.
Importance of Respiration
1
3.
Breathing and Respiration
4.
5.
6.
7.
a.
Breathing
1
b.
 Activity 1
 Activity 2
Breathing rate
1
2
4
c.
 Activity 3
 Activity 4
Is breathing and Respiration the same?
4
5
5
Aerobic and Anaerobic Respiration
5
a.
Aerobic
5
b.
 Activity 5
Anaerobic
5
6

6
Activity 6
Respiratory System of Humans
8
a.
Nose
9
a.
 Activity 7
 Worksheet 1
Wind pipe/Trachea
10
11
12
b.
Lungs
12
c.
Bronchi/Bronchioles
12
Mechanism of Breathing
13
a.
 Activity 8
 Activity 9
 Worksheet 2
Journey of Oxygen and Carbon dioxide in body cells
14
15
16
17
b.
 Worksheet 3
How is Energy produced?
18
19
Breathing in Other Animals
19
a.
19
Earthworm b.
Insects
c.
Frog
20
d.
Fish
20
8.
Respiration and Exchange of gases in Plants
9.
Post Content Worksheets
20
23-27
10. Glossary
28
11. E – Resources 29
Preface
The Curriculum initiated by Central Board of Secondary Education -International (CBSE-i)
is a progressive step in making the educational content and methodology more sensitive and
responsive to global needs. It signifies the emergence of a fresh thought process in imparting a
curriculum which would restore the independence of the learner to pursue the learning process
in harmony with the existing personal, social and cultural ethos.
The Central Board of Secondary Education has been providing support to the academic needs of
the learners worldwide. It has about 11500 schools affiliated to it and over 158 schools situated
in more than 23 countries. The Board has always been conscious of the varying needs of the
learners and has been working towards contextualizing certain elements of the learning process
to the physical, geographical, social and cultural environment in which they are engaged. The
CBSE-i has been visualized and developed with these requirements in view.
The nucleus of the entire process of constructing the curricular structure is the learner. The
objective of the curriculum is to nurture the independence of the learner, given the fact that every
learner is unique. The learner has to understand, appreciate, protect and build on knowledge,
values, beliefs and traditional wisdom. Teachers need to facilitate the leaner to make the
necessary modifications, improvisations and additions wherever and whenever necessary.
The recent scientific and technological advances have thrown open the gateways of knowledge
at an astonishing pace. The speed and methods of assimilating knowledge have put forth many
challenges to the educators, forcing them to rethink their approaches for knowledge processing
by their learners. In this context, it has become imperative for them to incorporate those skills
which will enable the young learners to become 'life long learners'. The ability to stay current,
to upgrade skills with emerging technologies, to understand the nuances involved in change
management and the relevant life skills have to be a part of the learning domains of the global
learners. The CBSE-i curriculum has taken cognizance of these requirements.
The CBSE-i aims to carry forward the basic strength of the Indian system of education while
promoting critical and creative thinking skills, effective communication skills, interpersonal
and collaborative skills along with information and media skills. There is an inbuilt flexibility
in the curriculum, as it provides a foundation and an extension curriculum, in all subject areas
to cater to the different pace of learners.
The CBSE introduced the CBSE-i curriculum in schools affiliated to CBSE at the international
level in 2010 at primary and secondary level in classes I and IX and subsequently in the session
2011-12 initiated the
curriculum at Class II, VI and class X. The current session will take the curriculum forward to
classes III, VII and XI.
An important feature of the Senior Secondary Curriculum is its emphasis on the specialisation
in different fields of study and preparing a student for higher professional life and career at the
work place. The CBSE-i, keeping in mind, the demands of the present Global opportunities
and challenges, is offering the new curriculum in the subject of English, Physics, Chemistry,
Biology, Geography, Accountancy, Business Studies, Information and Communication
Technology, and Mathematics at two levels, Mathematics-I for the students of pure sciences
and Mathematics-II for the students of Commerce and other subjects.
There are some non-evaluative components in the curriculum which would be commented
upon by the teachers and the school. The objective of this part or the core of the curriculum
is to scaffold the learning experiences and to relate tacit knowledge with formal knowledge.
This would involve trans-disciplinary linkages that would form the core of the learning
process. Perspectives, SEWA (Social Empowerment through Work and Action), Life Skills
and Research would be the constituents of this 'Core'. The Core skills are the most significant
aspects of a learner's holistic growth and learning curve.
The International Curriculum has been designed keeping in view the foundations of the
National Curricular Framework (NCF 2005) NCERT and the experience gathered by the
Board over the last seven decades in imparting effective learning to millions of learners,
many of whom are now global citizens.
The Board does not interpret this development as an alternative to other curricula existing
at the international level, but as an exercise in providing the much needed Indian leadership
for global education at the school level. The Curriculum envisages pedagogy which would
involve building on learning experiences inside the classroom over a period of time. The
Board while addressing the issues of empowerment and capacity building of teachers believes
that all school must budget for and ensure teachers involved with CBSE-i are continuously
updated.
I appreciate the sincere effort put in by Dr. Sadhana Parashar, Director (Training) CBSE,
Dr. Srijata Das, Education Officer, CBSE and the team of Officers involved in the development
and implementation of this material.
The CBSE-i website enables all stakeholders to participate in this initiative through the
discussion forums provided on the portal. Any further suggestions are welcome.
Vineet Joshi
Chairman, CBSE
Acknowledgements
Advisory
Shri Vineet Joshi, Chairman, CBSE
Dr. Sadhana Parashar, Director (Training), CBSE
Conceptual Framework
Shri G. Balasubramanian, Former Director (Acad),
CBSE
Ms. Abha Adams, Consultant, Step-by-Step School,
Noida
Dr. Sadhana Parashar, Director (Training), CBSE
Ideators VI-VIII
Ms Aditi Mishra
Ms Guneet Ohri
Ms. Sudha Ravi
Ms. Himani Asija
Ms. Neerada Suresh
Dr. Rajesh Hassija
Ms Preeti Hans
Ms Neelima Sharma
Ms. Gayatri Khanna
Ms. Urmila Guliani
Ms. Anuradha Joshi
Mrs. Sonali Sinha Ms. Charu Maini
Dr. Usha Sharma
Prof. Chand Kiran Saluja
Dr. Meena Dhani
Ms. Vijay Laxmi Raman
Mrs. Avanita Bir
Ms. Malini Sridhar
Ms. Leela Raghavan
Dr. Rashmi Sethi
Ms. Seema Rawat
Ms. Suman Nath Bhalla
Prof Om Vikas
Material Production Groups: Classes VI-VIII
English :
Ms Neha Sharma
Ms Dipinder Kaur
Ms Sarita Ahuja
Ms Gayatri Khanna
Ms Preeti Hans
Ms Rachna Pandit
Ms Renu Anand
Ms Sheena Chhabra
Ms Veena Bhasin
Ms Trishya Mukherjee
Ms Neerada Suresh
Ms Sudha Ravi
Ms Ratna Lal
Ms Ritu Badia
Vashisth
MsVijay Laxmi
Raman
Core- Research
Ms. Renu Anand
Ms. Gayatri Khanna
Dr. N K Sehgal
Ms. Anita Sharma
Ms. Rashmi Kathuria
Ms. Neha Sharma
Ms. Neeta Rastogi
Ms. Manjushtha Bose
Ms. Varsha Manku
Dr. K L Chopra
Chemistry :
Ms. Poonam Kumar
Mendiratta
Ms. Rashmi Sharma
Ms. Kavita Kapoor
Ms. Divya Arora
Mathematics :
Ms. Deepa Gupta
Ms. Gayatri Chowhan
Ms. N Vidya
Ms. Mamta Goyal
Ms. Chhavi Raheja
Physics :
Ms. Vidhu Narayanan
Ms. Mukta Kaushik
Ms. Patarlekha Sarkar
Ms. Neelam Malik
Hindi:
Mr. Akshay Kumar Dixit
Ms. Veena Sharma
Ms. Nishi Dhanjal
Ms. Kiran Soni
Biology:
Mr. Saroj Kumar
Ms. Rashmi
Ramsinghaney
Ms. Prerna Kapoor
Ms. Seema Kapoor
Mr. Manish Panwar
Ms. Vikram Yadav
Ms. Monika Chopra
Ms. Jaspreet Kaur
Ms. Preeti Mittal
Ms. Shipra Sarcar
Ms. Leela Raghavan
CORE-SEWA
Ms. Vandna
Ms. Nishtha Bharati
Ms. Seema Bhandari
Ms. Seema Chopra
Ms. Reema Arora
Ms. Neha Sharma
ICT
Mr. Yogesh Kumar
Ms. Nancy Sehgal
Ms. Purvi Srivastava
Ms. Babita Mahajan
Ms. Ritu Arora
Ms. Swati Panhani
Ms. Chanchal Chandna
Geography:
Ms Suparna Sharma
Ms Aditi Babbar
History :
Ms Leeza Dutta
Ms Kalpana Pant
Ms Ruchi Mahajan
Political Science:
Ms Kanu Chopra
Ms Shilpi Anand
Economics :
Ms. Leela Garewal
Ms Anita Yadav
CORE-Perspectives
Ms. Madhuchhanda,
RO(Innovation)
Ms. Varsha Seth,
Consultant
Ms Neha Sharma
Chief Co-ordinators: Dr. Srijata Das, EO
Co-ordinators
Ms. Sugandh Sharma,
Ms.S. Radha Mahalakshmi, Dr Rashmi Sethi,
EO
E. O.
EO
Mr. Navin Maini, R O (Tech) Shri Al Hilal Ahmed, AEO Mr. R P Singh, AEO
Ms. Neelima Sharma,
Consultant (English)
Shri R. P. Sharma,
Consultant (Science)
Mr. Sanjay Sachdeva, S O
Ms. Madhu Chanda,
R O (Inn)
Ms. Anjali, AEO
RESPIRATION IN ORGANISMS
Introduction
Respiration is a process that involves exchange of oxygen from air with carbon dioxide
produced in living organisms. This unit is meant to investigate the importance of respiration for
living organisms. Through this unit learners will be able to correlate the structure of respiratory
organs with their functions and also differentiate between breathing and respiration.
This unit will also empower learners to analyze the link between respiration and the utilization
of oxygen to breakdown the assimilated food in order to release energy. It will also include the
study of the process of breathing in other organisms such as earthworm, cockroach, and fish.
It will provide learners with enough opportunities/occasions to explore process of respiration
and significance of exchange of gases in plants.
Importance of Respiration:
Recall from what you have studied in your previous class that respiration is a characteristic
feature of living organisms. It involves two main processes- breathing and energy release. The
oxygen taken in during breathing acts on assimilated food in the cells to release energy.
Breathing:
Breathing is the process of inhalation and exhalation of air. Let us carefully observe breathing
by performing an activity.
Activity-1
To experience
the process of
breathing.
Hold a deflated balloon.
Take a deep breath. Bring
the opening of the balloon
to your mouth and exhale
(blow out) into the balloon.
We will notice the balloon
gets inflated when we blow
into its mouth.
Diaphragm relaxes
1
Diaphragm contracts
Thus we observe and experience the process of taking in and out air during this activity?
http://www.merckmanuals.com/home/lung_and_airway_disorders/biology_of_the_lungs_and_airways/control_
of_breathing.html
Do the following activity, note down your observations and fill up the number of times you
breathe. Count one breath as one time inhalation and one time exhalation.
(One inhalation + one exhalation = 1 breath)
Activity-2
Rate of breathing varies with different types of activities in an organism
S. No.
Activity
1.
After resting for 10 minutes
2.
On the spot jogging for 5 minutes
Number of times you breathe in a minute.
2
S. No.
Activity
3.
After running for 2 minutes.
4.
After cycling for 10 minutes.
5.
After climbing stairs for two floors.
Number of times you breathe in a minute.
Observation: You will notice that the number of times you breathe in a minute varies with the
nature of the activities you perform.
Conclusion: We breathe faster when we perform strenuous physical activities.
3
Breathing Rate
The number of times a person breathes in a minute is called breathing rate. On an average,
an adult human being breathes 15-18 times in a minute. On exercising the breathing rate can
go up to 25 times per minute. The rate of breathing is not constant but varies during different
activities.
We have learnt in our previous classes that exhaled air contains carbon dioxide. Let us perform
an activity to prove the same.
Activity- 3
To prove that the exhaled air contains Carbon dioxide
Think of an experiment you can perform to prove that carbon dioxide is given out as a result of
exhalation. You are given the following items. Lime water, a glass, a straw.
The carbon dioxide present in the exhaled air turns the colour of lime water milky. This
proves that exhaled air contains carbon dioxide.
you must have noticed someone cleaning their spectacles by blowing on the lens and then
wiping it. We will notice when we do this, the lens becomes clean.
Let us try to find out the reason for this.
Exhaled air contains water vapours.
4
Activity-4: (Group activity)
To prove that the exhaled air contains water vapours
Stand in front of a mirror and breathe out. Mirror becomes hazy. This is because there is
condensation of water vapours into small droplets of water. This proves that exhaled air
contains water vapours.
Is Breathing and Respiration the same?
The term respiration is not the same as breathing. Respiration includes breathing and break
down of assimilated food with the help of O2 to release energy. Release of energy from
organic compounds in cells is in the form of ATP (energy rich molecules). ATP (Adenosine Tri
Phosphate) is the molecule which directly provides energy to various biological reactions that
take place in our body. This process takes place in every cell of the body, hence is known as
Cellular Respiration.
So breathing is a physical process during which there is no oxidation of food. Breathing
is a physical process which is simply exchange of gases, whereas cellular respiration is a
biochemical process which involves breakdown of food (oxidation of food) to release energy.
Therefore, we can conclude, that what we generally call respiration actually includes both
breathing and cellular respiration.
Aerobic and Anaerobic Respiration
Aerobic Respiration:
Observe the demonstration of an experiment showing that living organism breathes.
Activity: 5
Apparatus required: conical flask, bent tube, cork, vaseline, coloured water, germinating
seeds.
Procedure: Take some germinated
seeds in a conical flask. Fix the
delivery tube bent in “U” shape
with a cork to the conical flask
and coloured water in a beaker.
Put KOH (potassium hydroxide)
pellets or solution in a small test
tube and suspend with a thread
tied to the rubber stopper in the
conical flask as shown in the
diagram.
5
Keep the other end of the delivery tube dipped in coloured water. Make the apparatus air tight
by using vaseline. After some time the water level will rise.
You will observe that there is an increase in the level of coloured water of the delivery tube
which is immersed in the beaker containing water.
Inference: This happens because the oxygen which is present in the conical flask is utilized
by the germinating seeds and they release carbon dioxide. This carbon dioxide is absorbed by
the potassium hydroxide and partial vacuum is created. The coloured water rises to fill up the
vacuum space. Thus this experiment shows that living organisms such as germinating seeds
respire.
Suggestion: This experiment may be repeated by replacing germinating seeds with flower
buds.
This experiment shows that germinating seeds take in oxygen and give out carbon dioxide.
The process of respiration that utilizes oxygen is known as aerobic respiration.
In the process of aerobic respiration, breakdown of food/glucose takes place in the presence of
oxygen releasing CO2, water vapour and energy. Organisms that carry out aerobic respiration
are called aerobes.
This process is summed up in a word equation below:
Food
with the use Oxygen
CO2+ H2O + Energy
Anaerobic Respiration:
There are some organisms like yeast, bacteria and parasites that can survive in the absence of
air. They can break glucose to release energy without using oxygen. In this type of breakdown
of glucose, in the absence of O2 very little energy is released.
Activity 6: Some organisms respire even in the absence of Oxygen.
Observe the demonstration of an experiment which shows, that some organisms even respire in
the absence of Oxygen. Take some sugar solution in a boiling test tube; add some yeast powder
to that solution.
Fix the cork. Leave the test tube for two days.
Observation:

Lime water turns milky

Smell of alcohol is noticed.
This process of respiration in yeast can be
represented by the following equation.
6
Glucose
without the use Oxygen
Ethyl Alcohol + CO2 + Energy
Industrial application of Yeast.
Yeast produces alcohol and helps
in the preparation of bread and
cheese.
Conclusion: “Yeast convert sugar into alcohol”. It respire in the absence of oxygen.
Organisms which carry out respiration in the absence of oxygen to fulfill their energy needs
are called Anaerobes. These organisms have the ability to survive for longer period of time
without using oxygen than aerobes.
Thus we can say that the process of respiration that takes place in the absence of oxygen is
known as anaerobic respiration.
Observe the following pictures
Why do people get muscle cramps after heavy exercises such as cycling, swimming or
jogging for long time?
http://www.pixelatestudio.com/cycling_photos.htm
http://new-york-chiropractor.blogspot.in/2010/12/so-you-were-playing-sports-and-your-leg.html
http://en.topictures.com/physical%20therapist
During heavy exercises, fast running or weight lifting, the demand for energy is very high,
but the supply of oxygen is very limited and the muscle cells have to respire without adequate
supply of oxygen. During this type of respiration, energy released is very less as compared to
aerobic respiration.
This can be represented by the following equation.
7
Glucose
in the absence of Oxygen
Lactic acid + Energy (in the muscle cells)
The muscle cramps formed after heavy exercises are because of partial breakdown of glucose
into Lactic acid which accumulates in muscles.
Relief from cramps
We can get relief from cramps by hot water bath or
massage. This improves the blood circulation and
restores the supply of O2 resulting in the complete
breakdown of accumulated lactic acid into CO2 and
water and thus giving relief from cramps.
In aerobic respiration
glucose produces 38
molecules of ATP and in
anaerobic respiration the
energy yield is 2 molecules
of ATP.
Respiratory System in Humans:
Respiratory system facilitates exchange of oxygen and carbon dioxide required by the body.
The respiratory system can be divided into three parts.

Air passages and tubes include the nose, wind
pipe, bronchi, and bronchioles.

Air pump includes chest cavity containing lungs
and diaphragm.

Respiratory surface includes alveolar lining and
blood capillaries.
Fig: Respiratory system of humans
http://people.eku.edu/ritchisong/301notes6.htm
8
Organs of Respiration in Humans:
The organs of respiration are Nose, wind pipe (trachea), Lungs, bronchi and bronchioles.
Nose: Air normally enters into lungs through the nose. Hair in the nose traps some of the dust
particles that come along with the air. The lining of the nose also produces mucus (a watery
liquid) which keeps the air moist and does not allow any dust particles to enter along with air.
The hair and mucus act as filters and allow clean air to pass through the nostrils.
As the air passes along
the nasal passage, the blood vessels
beneath the nasal lining release heat.
This heat regulates the temperature of the
air before it passes into the lungs.
That is why in winters also the air that
we breathe out is warm.
What would happen if we breathe through our mouth? Let us do an activity to understand the
significance of correct way of breathing.
9
Activity–7: Inhaling air through nose and mouth
Do the following activity to experience inhaling air through nose and mouth. Fill up worksheet
7.
Inhaling air through Nose
Inhaling air through mouth
http://thebreathingman.wordpress.com/article/nose-breathing-202i29i90v7sn-41/
http://www.rxlist.com/aerospan-hfa-drug/medication-guide.htm
10
Worksheet-1
Way to breathe
Breathe through the nose and through the mouth each for 5 minutes and note the difference by
answering the following questions in Yes or No as applicable:
1. Does your throat become dry? 2. Do you feel irritation in your throat?
3. Now what do you advise yourself?
Inhaling
Inhaling
through nose
through mouth
_______________
_______________
_______________
_______________
_______________
When we breathe through our mouth, there is nothing to stop the dust particles and harmful
germs to enter the throat thus causing irritation in the throat.
What is smokers cough?
What will happen in severe bronchitis?
What is asthma?
11
Wind pipe/Trachea
From the nose, the air enters pharynx. From
the pharynx the air enters into a tube called
wind pipe also known as trachea. Trachea is a tube
about 12 cm in length and 2.5 cm in diameter in an
adult. It might be interesting to note that, whether
the air enters through the nose or the mouth, it will
pass into the wind pipe through the pharynx.
Lungs
There is a pair of lungs in a human body, present
on each side of the chest cavity. Lungs are the main
respiratory organs in our body and are enclosed
in chest cavity. This cavity is protected by the
bony structures called ribs. At the base (lower
end) of the chest cavity there is a large muscular sheet called diaphragm (Observe the
diaphragm in the picture given above), which separates the upper part (thoracic cavity)
of the body from lower part (abdominal cavity) of the body. The rib bones are attached to
the muscles. The muscles of the ribs and diaphragm move during breathing.
http://www.cancer.umn.edu/cancerinfo/NCI/CDR269299.html
Bronchi and Bronchioles:
The wind pipe divides into two smaller
tubes called bronchi (bronchus– singular).
Each bronchus divides into many smaller
bronchioles. Each bronchus enters the
lungs and branches into bronchioles. At the
end of these bronchioles are air sacs called
alveoli.
The air after entering the bronchi, reaches
bronchioles and then into alveoli (air
sacs).
From the alveoli the air diffuses into the
blood capillaries as they are surrounded
by the blood vessels. The carbon dioxide
present in the blood vessels enters the
alveoli and is exhaled through the nostrils
http://www.naturalhealthschool.com/bronchi_trachea.html
along with water vapours.
12
Mechanism of Breathing:
There are two breathing movements
1)
Inhalation
2)
Exhalation
Inhalation
During inhalation:

Inter-costal muscles contract.

Ribs move outwards and
upwards.

Diaphragm is pulled down
into a flat position.

Volume of the chest cavity
increases.

Pressure inside the lungs reduces.
Therefore air rushes into the lungs.
13
Exhalation:
During exhalation:

Rib muscles relax

Ribs move inwards and downwards.

Diaphragm moves up.

Volume of the chest cavity decreases

Pressure inside the lungs increases.
Therefore air is pushed out of the lungs.
The number of times a person
breathes in a minute is called breathing rate.
On an average an adult human being breathes
15 – 18 times in a minute. On exercising the
breathing rate can go up to
25 times per minutes.
Watch these Respiration Videos
http://www.youtube.com/watch?v=HiT621PrrO0
http://www.youtube.com/watch?v=RfCeiK0xtR0&feature=related
http://www.youtube.com/watch?v=12ddbrqpZiQ&feature=related
Activity-8: Increase in the chest size during inhalation
Instructions:
Measure the size of your chest with a measuring tape and record your observations. Now take
a deep breath and hold it. Again measure the size of your chest.
Study the increase in the chest size (in cm) of 4 of your classmates, complete the following
table and note the measurements.
Size of the Chest
Sl. No.
Name of the student
Normal
After a deep
Breathing (in cm) breath (in cm)
You may notice the variation in the chest size among the students.
14
Difference in
size (in cm)
Activity-9: To understand the mechanism of breathing by a
simple model.
Take two bell jars. Take a Y shaped glass tube and fix
two balloons on each end. Insert this Y shaped glass tube
with balloons in a bell jar or plastic transparent bottle as
shown in the diagram.
Tie a thin rubber sheet around the bottom of the bell jar.
This setup is a replica of the human respiratory system.
The bell jar represent the chest cavity, the balloons
represent the lungs, and the rubber sheet represent the
diaphragm. Pull the rubber sheet down, to show that:
Inhalation
i) Space in the jar increases
ii) Balloons get inflated
iii) Air enters the balloons
This is how we inhale.
If we do the reverse we will find:
i)
ii)
Exhalation
hyperphysics.phy-astr.gsu.edu
Space in the jar decreases
Balloons get deflated
iii) Air leaves the balloons
This is how we exhale.
15
Worksheet 2
Process of inhalation and exhalation
(A) The steps for the process of inhalation are given below. Write the corresponding steps of
the process of exhalation on the right hand side.
Process of Inhalation
Process of Exhalation

Ribs move outwards and upwards.
________________________________

Diaphragm is pulled down.
________________________________

Volume of the chest cavity increases
________________________________

Pressure inside the lungs reduces.
________________________________

Air enters the lungs.
________________________________
(B) Observe the diagram given below.
Write the parts of human respiratory system that correspond to the labeled parts: i), ii) & iii).
Corresponding parts of human respiratory system
16
Journey of Oxygen and Carbon Dioxide in Body Cells:
Oxygen from the inhaled air diffuses through the walls of the alveoli into the blood capillaries.
This oxygen is carried to all cells of the body, where it breaks down (oxidizes) the assimilated
food to release energy.
Carbon dioxide is carried from body cells into the blood capillaries. From the blood capillaries
it diffuses into alveoli. It is then pushed out through bronchioles, bronchi, and exhaled through
the nostrils. Blood moves into the capillaries very quickly.
web.med.unsw.edu.au
17
Worksheet-3
Trace the path of oxygen and carbon dioxide
Trace the path of oxygen and carbon dioxide in the table given below.
Write the names in correct sequence of the two paths. Use red colour for tracing path of oxygen
and blue colour for carbon dioxide. Choose the appropriate words from the list provided below,
the first step of each path is done for you.
Trachea, Alveoli, Body cells, Bronchioles, Bronchi, Blood capillaries, Nose
Path of oxygen
Path of carbon dioxide
1
Nose
1.
Body cells
2
________________________
2
________________________
3
________________________
3
________________________
4
________________________
4
________________________
5
________________________
5
________________________
6
________________________
6
________________________
7
________________________
7
________________________
18
How is Energy Produced?
We have studied that the digested food substances enter the cells of the body through the blood.
The oxygen of the air enters the blood from alveoli.
The blood carries the oxygen to the cells of the body during its circulation. The oxygen acts
upon the food present in the cells of the body to produce energy and release carbon dioxide.
The change can be summarized as:
Food + oxygen
CO2 (carbon dioxide) + Energy + Water vapours
Since the energy is released in the cells, the process is known as cellular respiration.Cellular
Respiration is a Biochemical Process.
Breathing in other animals:
We know that animals obtain energy by the oxidation of assimilated food. We have seen that
respiration needs continuous supply of oxygen to break down the food and carbon dioxide
released during respiration. Let us see how the exchange of gases takes place in some other
animals.
Earthworm
Earthworms live in damp soil. Gaseous exchange
takes place through their moist skin. In these
earthworms, the thin and moist skin is richly
supplied with blood vessels (capillaries) which
absorb oxygen from the atmosphere and release
carbon dioxide. Earthworms breathe through their
moist skin.
Insects
Air reaches various parts of the body of an insect through
an elaborate system of branching tubes called tracheae. The
tracheae open outside through holes called spiracles. Most
of the tracheal tubes run along and across the body and
divides into smaller tubular structures called tracheoles.
Larva of an insect
Oxygen enters tracheal system through the spiracles and
diffuses into the body cells. Carbon dioxide diffuses out
http://www.entomology.umn.edu/museum/projects/Interactive_Keys/
Intro_tutorial/GLOSSARY/Spiracles.html
19
of the body cells into tracheal system and is carried out of the body through the spiracles.
Frog
Frogs can live both in water and on land; therefore, they can breathe both on land and in
water. They have a pair of lungs and a large opening of the mouth (buccal cavity) to enable
them to breathe on land. They have a moist, slimy skin to enable them to breathe in water.
Since they live in amphibious habitat, they are known as amphibians.
Fish
Fishes absorb dissolved oxygen present in water by gills. Gills are projections of the skin and
are richly supplied with blood vessels for exchange of gases. A fish gulps water through the
mouth and forces it between the gills on each side of its neck. As water flows across the gills,
the oxygen in it gets diffused into the blood stream. At the same time carbon dioxide in the
blood stream diffuses into the water.
Organs of breathing of different animals help them to breathe in their specific habitats.
So we can notice that animals living in soil such as earthworm breathes through moist skin,
land animals such as insects breathe through spiracles and aquatic animals such as fish breathe
through gills. Animals such as frogs that can live on land and in water have lungs to breathe
while on land and moist skin to breathe while in water.
We can conclude that animals of different habitats have different organs of breathing.
Respiration in Plants:
Plants do not make breathing movements to exchange oxygen and carbon dioxide. They rely
on the process of diffusion through which the gases move in and out of their cells and their
body.
20
http://evolution.berkeley.edu/evolibrary/article/mcelwain_02
Exchange of gases in Plants
Like all other living organisms, plants also respire for their survival for which they take in
oxygen from the air and give out carbon dioxide. Plants do not have any organ system or organs
for breathing. It is interesting to note that in plants, exchange of gases takes place by simple
diffusion directly into each cell through the openings present in epidermis called stomata.
Even the stems have openings called lenticels that help in the exchange of gases. Lenticels
are present in older roots also. These pores on leaves, stems and roots allow oxygen, carbon
dioxide and water vapours to come in and out of the plant body. Leaves and stems exchange
gases from the air they are exposed to, whereas roots which grow under the soil take up air
from the air spaces present between soil particles.
Root
Hairs
Absorb
water
and
Nutrients
from the
Soil
http://preuniversity.grkraj.org/html/4_PLANT_AND_WATER_RELATIONSHIP.htm
21
Recall, that during photosynthesis, plants take in carbon dioxide and give out oxygen. We also
know this process takes place only in the presence of light.
Now we also know living organisms, including plants, take in oxygen and give out carbon
dioxide during respiration. This process takes place throughout the life of the organisms.
We can conclude that exchange of gases through the stomatal pores is due to respiration and
photosynthesis during the day, whereas at night, it is only due to respiration.
So, we have learnt that respiration is an important biological process in all living organisms.
It is through respiration that the living organisms get the much needed energy for their
survival.
22
POST CONTENT WORKSHEET 1
1)
List the similarities and differences between aerobic and anaerobic respiration.
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
2)
Breathing rate is-
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
3)
Why do we sneeze when we inhale dust?
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
4)
How are process of inhalation and exhalation related to each other?
______________________________________________________________________
______________________________________________________________________
_____________________________________________________________________
5)
Why does our breathing become faster after running?
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
6)
Why do we yawn when we are sleepy?
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
7)
Give simple equations for the following types of respiration:a)
Aerobic respiration
b)
Anaerobic respiration in yeast
23
c)
Anaerobic respiration in the muscles of man.
8)
Why do we feel hungry after a vigorous exercise session?
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
9)
Draw and label the parts of the human respiratory system.
10) Describe in brief the mechanism of breathing.
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
11) Depict mechanism of breathing diagrammatically.
12) Give an experiment to prove that we exhale air with CO2 and water vapours.
______________________________________________________________________
24
______________________________________________________________________
______________________________________________________________________
13) Complete the statements given below by choosing the most appropriate word from the
list given below:
Diaphragm, Ribs, carbon dioxide, inwards, outwards, upwards, downwards, 15-18
times per minute, 40 times per minute, increases, decreases
a)
___________ is located at the base of the chest cavity.
b)
During heavy exercises, we get cramps in the legs due to the accumulation of
___________.
c)
Normal range of breathing rate in a healthy adult at rest is ___________ per
minute.
d)
During inhalation, the ribs move ___________ and ___________.
e)
The size of the chest cavity ___________ during inhalation.
14) ATP stands for.
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
25
POST CONTENT WORKSHEET 2
1.
State if the following statements are true or false
(T / F)
a)
b)
c)
d)
(T / F)
(T / F)
(T / F)
(T / F)
Plants carry out respiration only during the day.
Photosynthesis takes place only during the day.
Frogs breathe both through lungs and skin.
Cockroaches respire through lungs
2)
Explain briefly how insects respire?
3)
Earthworms have moist skin. Why?
4)
How do gills help fishes to breathe under water? Also draw diagram to show gills in a
fish.
______________________________________________________________________
______________________________________________________________________
5)
What are stomata? Where would we look for them?
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
6)
Explain how roots breathe.
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
26
7)
What will happen if a potted plant is flooded with water?
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
8)
Why do we use flower bud/ germinating seeds in the experiment which shows respiration
occurs in living organisms?
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
27
Glossary
Toxic
: poisonous and harmful to people.
Diffusion
: random movement of molecules (liquid or gas) resulting in mixing in
another substance.
ATP
: energy rich molecule (full form - Adenosine Tri Phosphate) in the
cells that lets the energy go from it for chemical reactions.
Biochemical
: relating to the chemical substances and processes in living
organisms.
Vacuum
: space completely empty of all substances including air or gases.
Inhalation
: taking in (inhale) air during breathing.
Exhalation
: giving out (exhale) air during breathing.
Metabolism
: biochemical processes in cells necessary for life, all the chemical
processes by which cells produce the energy and substances necessary
for life.
Fermentation
: a chemical change due to the action of Yeast or Bacteria often changing
sugar to alcohol.
Anaerobic
: a process or a happening that does not need oxygen.
Aerobic respiration : the process of respiration that requires oxygen in order to release
energy by the breakdown of food.
Alveoli
: the air sacs through which the air diffuses into and out of blood
capillaries from bronchioles located in the lungs.
28
E – Resources
http://www.getbodysmart.com/ap/respiratorysystem/zonesdivisions/tutorial.html
http://www.getbodysmart.com/ap/respiratorysystem/menu/menu.html
http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter25/ animation gas_
exchange_during_respiration.html Gas Exchange Animation
http://www.youtube.com/watch?v=HiT621PrrO0
Respiration Video
http://www.youtube.com/watch?v=RfCeiK0xtR0&feature=related Respiration Video
http://www.youtube.com/watch?v=12ddbrqpZiQ&feature=related Respiration Video http://
www.youtube.com/watch?v=Mf8xTqfspp4 Diaphragmatic breathing animation
http://www.daviddarling.info/encyclopedia/Respiratory_system.html Gas Exchange in Lungs
http://www.health.com/health/library/mdp/0,,tp10237,00.html Gas Exchange in Lungs
http://www.tutorvista.com/content/biology/biology-iv/respiration-animals/breathingmechanism.php Experiment on Breathing Mechanism
http://www.ischool.zm/es/STUDY%202.html
Experiment on Breathing Mechanism
http://www.merckmanuals.com/home/lung_and_airway_disorders/biology_of_the_lungs_
and_airways/control_of_breathing.html Diaphragm movements with breathing
http://www.pixelatestudio.com/cycling_photos.htm Cyclist
http://en.topictures.com/physical%20therapist Muscular Pain in legs
http://thebreathingman.wordpress.com/article/nose-breathing-202i29i90v7sn-41/ Breathing
from Nose
http://www.rxlist.com/aerospan-hfa-drug/medication-guide.htm
http://people.eku.edu/ritchisong/301notes6.htm Breathing from Mouth
Respiratory System
http://www.naturalhealthschool.com/bronchi_trachea.html Trachea
http://www.cancer.umn.edu/cancerinfo/NCI/CDR269299.htm Diaphragm
http://www.youtube.com/watch?v=HiT621PrrO0
Respiration Video
http://www.youtube.com/watch?v=RfCeiK0xtR0&feature=related Respiration Video
http://www.youtube.com/watch?v=12ddbrqpZiQ&feature=related Respiration Video
http://preuniversity.grkraj.org/html/4_PLANT_AND_WATER_RELATIONSHIP.html
Absorption by roots
29