Hardwork and Practice are the key to Success. Best of Luck for your studies by the group of USacademy.

1. Chapter-1
Life Processes
USacademy.in
Fly beyond your dream

2. Identifying Living
organisms
• They breathe and can
work by itself.
• Movement of molecules which
are not visible through naked
eyes is also necessary for life.
Fact:- Virus doesn't shows
movement until it enters a host body.
That's why they are considered as
living as well as non-living.

3. Why are molecular
movements needed for
life ?
As a multicellular organism is
made up of many tissues and
thus organs. Sometimes, due to
the effect of environment this
organized structure of an
organism are likely to keep
breaking down over time. If this
structure breaks, then the
organism will no longer be alive.
So, molecular movement is
needed to keep repairing and
maintaining the structure of
an organism.

4. What is required for the maintenance Process ?
- Energy
Where does it come from ?
- from outside of an organism i.e, food
Intake of food- Ingestion(Nutrition)
- Additional raw material is required for Growth of the body which comes from outside.
Life on earth depends on
carbon based molecules. Thus most
of the food resources are also carbon
based.
Depending on the complexity of
carbon sources, different organisms
can then use different nutritional
processes.
The outside sources of energy could be
quite varied as environment is not under
our control. Therefore, the sources of
energy need to be broken down or built
up in the body itself. The energy should
be uniform, so that it could be used for
various molecular movements for
maintaining life processes.

5. How the energy is being built up in the body?
Food Molecules are broken down by oxidizing reducing reactions(with the help of oxygen).
Many organisms use oxygen for breaking down food. Thus energy is produced for cellular
needs(cells functioning). The process mentioned here is known as respiration.
Unicellular Organisms- As, Unicellular organisms entire surface is in contact with the environment no specific organ
is needed for intake of food exchange of gases and for excretion.
Multicellular organisms- As all the cells of a multicellular organism is not in contact with the environment simple
diffusion will not meet all its requirements. That's why Transportation system is there to transport food
and oxygen to all the cells for maintaining life process.
When chemical reactions use carbon source(food) and oxygen for energy generation, they create by products
which are not only useless but also harmful for us. To remove those harmful toxic material, Excretory System is
required.

6. Life Processes ?
Processes which are essential for our survival or which maintains the body's structure
are known as Life Processes.
The processes essential for maintaining life are:-
I. Nutrition
II. Digestion
III. Respiration
IV. Transportation/Circulation
V. Excretion
- Nutrition is the food we eat and how it affects our Health.

7. Nutrition
Autotrophic Heterotrophic
Autotrophic Nutrition- Carbon and energy requirements
of autotrophs is fulfilled by photosynthesis. It is the process
by which autotrophs take in substances and convert them
into stored form of energy.
Chemical formula of Photosynthesis
6CO2 + 12H2O C6H12O6 + 6O2 +H2O
- Carbohydrate not in use is stored in the form of starch (a
complex sugar) .
Reserved for future use when require by the plant.
- In humans, energy not in use is stored in the form of
Glycogen (a complex sugar).
What actually happens during the process
of Photosynthesis ?
-light energy is absorbed by chlorophyll.
-light energy chemical energy
Splitting of water hydrogen + oxygen
-Carbon dioxide is reduced to carbohydrate.
Stomata- pores on the epidermis of leaf is known as
Stomata. Massive amount of exchange of gases takes
place through this pores.
Note- gaseous exchange also occurs across the
surface of stems and roots.
- Guard cells functioning is opening and closing of
stomata.
-Guard cell swells when water enters in it. (opens)
-Guard cell shrinks when water comes out. (closes)

8. Requirements of
Photosynthesis
• Chlorophyll (in leaves)
• Sunlight and Carbon dioxide (atmosphere)
• Water and Minerals (from soil- in terrestrial plants)
Nitrogen- essential element required for synthesis
and of food and other compounds
Taken by plants in the form of inorganic nitrate (NO3)
or nitrite (NO2) or from directly the environment during
lightning / nitrogen converted by nitrogenous bacteria.

9. Heterotrophic Nutrition
Heterotrophs are the organisms which depends on autotrophs for their food. The mode
of nutrition used by them is known as Heterotrophic Nutrition.
Saprophytic nutrition- saprophytes take nutrition from dead and decay matter. The
mode of nutrition used by them is known as saprophytic nutrition. Eg. mushrooms etc.
Parasitic Nutrition- parasites depends on the host for obtaining food. The mode of
nutrition used by them is known as Parasitic Nutrition. Eg. cuscuta (amar-bel), ticks, lice,
leeches and tapeworms.
Parasitic Nutrition
Saprophytic nutrition

10. How do organisms obtain their food ?
-Single celled- take in food through its entire surface.eg-amoeba uses pseudopodia for
ingestion. (Amoeba)
(food particles) (food vacuole)
Complex substances break into simpler
ones
Undigested food is excreted out of the body
(Inside)
Absorbed food diffuses into cytoplasm
Paramecium is also a unicellular organism. It
has definite shape and food is taken on a
specific spot. The food is moved to this spot by
movement of cilia covering its entire surface.

11. Nutrition in Human beings ?
Mouth- As the food enters it is broken down into tiny uniform pieces. Salivary gland
secretes saliva which softens the food for easy passage through Alimentary canal
Biological catalyst called enzymes break the food into smaller molecules so that it
could be absorbed easily by the alimentary canal.
Food Oesophagus Stomach Small intestine Through anus the
(Mouth)
Salivary Gland Secretes salivary amalyse (Enzyme) Breaks starch into simpler
sugars
The lining of alimentary canal that contract rhythmically in order to push the food forward.
These movement occur all along the gut.
excreta removes out
(Digestion)

13. Role of stomach in digestion
Stomach is a large organ which expands when food enters in it. Muscular wall of the stomach helps in
mixing food thoroughly with more digestive juices.
Gastric glands in the walls of stomach secretes HCl , Protein digesting enzyme (Pepsin) and
mucus. HCl makes the medium acidic Mucus helps to prevent stomach from acid;
HCl Helps Pepsin to do its work.
Acidity When HCl secretes in excess amount.
Exit of food in stomach is regulated by Sphincter muscle. Releases food in small intestine (7.5m) is
small amounts.
Length of intestine ∝ the kind of food they eat
Herbivores – long intestine (complex food) cellulose
Carnivores- small intestine (simpler food) meat

14. Role of Small intestine in digestion
Site of complete digestion of carbohydrates, proteins and fats.
Acidic food from stomach has to be made alkaline for the pancreatic juice to act.
Bile juice (Liver)- acts on fats (present as large globules in s.m. Which makes difficult for
the enzyme to act). Bile salt breaks the fat making easy for the pancreatic enzyme to act.
Pancreatic juice (Trypsin)- digests proteins and lipase for breaking down emulsified fats.
Walls of small intestine- intestinal juice (enzyme) present in it converts proteins into
amino acid, carbohydrate into glucose and fats into fatty acid and glycerol
Villi – finger like projection in s.m. increasing the surface area for absorption. Has blood
vessels which takes the absorbed food to each cell of the body.

15. Role of Large intestine in Digestion
The left unabsorbed food is sent into large intestine where more water and salts are
absorbed. Rest of the waste is then excreted out of the body via anus (the process
is known as egestion) Exit of waste material is regulated by Anal sphincter.
Tooth decay and Dental caries
Causes gradual softening of enamel and dentine. Begins when bacteria acts on sugar
demineralizes /softens the enamel. Bacterial cells stick together with the food particle to form
Dental Plaque. Plaque covers the tooth surface and prevents it from neutralizing. Brushing
tooth after the meal removes the plaque thus prevent the tooth from decaying.

16. Respiration (Breakdown of Glucose)
• Some uses oxygen to break down glucose completely into CO2 and H2O some other
organisms do not involve oxygen.
• In all cases
Breakdown of glucose (6 carbon molecule) into (a 3 carbon molecule) called Pyruvate.
• Breaking of glucose takes place in cytoplasm.
• Breaking of pyruvate takes place in mitochondria.
I. Pyruvate Ethanol + CO2 +Energy (this process takes place in yeast during
respiration) (Absence of Oxygen)
II. Pyruvate Lactic acid + Energy (in our muscles) (Lack of oxygen)
III. Pyruvate CO2 + Water + Energy (in mitochondria) (Presence of Oxygen)

17. Respiration (Breakdown of glucose)
Types of Respiration
Aerobic Respiration – takes place in the presence of oxygen.
Anaerobic Respiration – takes place in the absence of oxygen.
• The energy released during cellular respiration is immediately used to synthesize a
molecule called ATP.
• ATP (when broken down) gives a fixed amount of energy used for the
endothermic reaction taking place in the cell.
• ATP – Energy Currency of the cell (Made from ADP and inorganic phosphate)

18. Respiration in Plants
• Exchange off gases takes place through stomata (large intercellular spaces ensures all
cells are in contact with air).
• Direction of diffusion depends upon the environmental conditions and the requirements
of the plant.
• At night, no photosynthesis takes place. CO2 elimination is the major exchange activity
going on. Most of the plants take in oxygen in the night time only the trees like Peepal
and Neem takes CO2 at night.
• At day, CO2 generated at night is used up for photosynthesis (this is the reason for no
CO2elimination during daytime).

19. Respiration in Aquatic organisms
• Aquatic organisms takes oxygen dissolved in water, it is comparatively less than
that present in the air. This is the reason behind faster rate of breathing in
aquatic organisms as compared to terrestrial one.
• Fishes takes in water 💦 through their mouth oxygenate it and pass the rest of the
water through its gills (this is the reason behind opening of mouth and gills at the same
time in fishes).

20. Respiration in Terrestrial organisms
• Terrestrial organisms take up oxygen from the air and is absorbed through different
organs in different animals.
• Those organs have a structure that increases the surface area which is in contact with
oxygen rich atmosphere. As exchange of gases takes place here, the surface is fine
and delicate (carefully handled).
• The organs are protected by placing it within the body.
• An specific organ is there in every animal through which the passage of air takes
place..
• In humans, air is taken through Nasal passage/Nostrils.. Fine hair particle called cilia
and Mucus are present in the nostrils which helps to filter air.
• Air Throat (rings of cartilage ensures that air and food do not collapse with each
other) Lungs

21. Respiration in
Humans
Smoking 🚭 an injurious habit
Smoking destroys those cilia which helps
to filter air. As cilia is destroyed dusts,
germs and bacteria's enters in our body
and causes infection and diseases.

22. Respiration
in Humans
Alveoli - Sac like structures
present in lungs which helps in
transportation of oxygen are
known as Alveoli.
• Walls of alveoli have blood
vessels called alveolar blood
vessels where O2 diffuses and
passes it to heart then to rest of
the body.

23. Respiration in Humans
• In large body sized animals, diffusion pressure alone cannot take care of O2
delivery to all the parts of the body. Instead, they have respiratory pigments to
carry O2 to the tissues which are deficient in it.
• In Human Beings the respiratory pigment is Hemoglobin which has a very high
affinity for O2 (means, oxygen is attracted towards hemoglobin).
• Diffusion pressure is the ability of ions and molecules of any substance to diffuse
from one area that is of higher concentration to that of lower concentration.

24. Respiration in Humans
How does alveoli increases gaseous exchange ?
Alveoli are folded as to increase their surface area so that large amount of oxygen
could diffuse. The linings of alveoli are also moist so that the gases can easily dissolve
and then can be transported to the cells.
• The lungs always contains a residual amount of air so that there is sufficient time
for O2 to be absorbed and CO2 to be released.
• CO2 is more soluble in blood as compared to O2. Therefore when blood reaches
the lungs CO2 can freely disassociate from hemoglobin and expelled out easily
from the body.

26. Transportation in
Humans
• Blood consists of a fluid medium
called plasma in which cells are
suspended. Plasma transports
food, CO2, nitrogenous waste
in dissolved form. Oxygen is
carried by RBCs.
Heart the Pumping Organ
• A muscular organ as big as our
fist. Because both O2 and CO2 are
to be transported by the blood.

28. Transportation in Humans
• As the air diffuses through alveoli into the bloodstream, pulmonary veins takes it to the left
atrium, the left atrium relaxes while it collects blood. Then it contracts, while the Left
Ventricle relaxes while receiving blood. It is similar in the case of right atrium and ventricle
too.
• Since ventricles have to pump blood to all parts of the body, they have thick muscular walls
then atria (plu. atrium). The valve ensures that blood does not flow backwards when the
atria or ventricles contract.
• Birds and mammals constantly use energy to maintain their body temperature (this is the
reason behind why oxygenated and deoxygenated blood have to be separated in
multicellular organisms).
• Amphibian and reptiles have 3 chambered heart while fishes have 2 chambered heart.
Valve- controls the flow of fluid

29. Transportation in Humans
Blood vessels
Artery- Transports blood to all parts of the body.
- they have thick & elastic walls as blood emerges from the heart under high pressure.
Veins- collects the blood from different organs and bring it back to the heart.
- No need of thick walls because the blood is no longer under high pressure instead they have valves
that ensures blood flow in one direction.
On reaching organ or tissue, artery divides into smaller vessels which are one cell thick called
capillaries to bring the blood in contact with all the individual cells. Exchange of materials
between blood and surrounding cells take place across this thin wall. Then capillaries join together to
form veins that convey blood away from organs and tissues.

30. Transportation in Humans
What happens if the system of tubes develops leak ?
It only happens when we get injured and bleeding starts. To minimize blood flow, platelet cells circulated
around the body plug these leaks.
Lymph- It's another type of fluid which is involved in transportation.
How is it formed ?
Some amount of plasma, proteins and blood cells escape from the capillaries into intercellular spaces to
form the tissue fluid.
Lymph is similar to plasma of blood but it is colorless and contains less protein.
Drains into lymphatic capillaries from the intercellular spaces and forms large Lymph vessels that finally
opens into large veins.
Function- carries digested + absorbed fat from intestine and drains excess fluid from extracellular
space into blood.

31. Transportation in Plants
• If the distance between soil containing organ and chlorophyll containing organ is large because of
changes in plant's body design then diffusion process will not be sufficient to provide raw material in
leaves and energy to plants.
• Plants have a large proportion of dead cells in many tissues. Result- Plants have low energy needs
and can use relatively slow transport system. Transport System can be very large in Tall trees.
Vascular Tubes
- Independently organised tubes.
I. Xylem- Transports water and minerals obtained from the soil.
Types – Trachea , - Vessels , - Xylem fiber , - Xylem Parenchyma
II. Phloem- Transports products of photosynthesis from leaves to various parts of the plant.
Types –Sieve tubes , - Sieve cells , -Companion cells , - Phloem fiber , - Phloem Parenchyma

32. Transportation in Plants
Transport of Water
• Xylem is appointed for transport of water in plants. Vessels and tracheid's found in stems, roots and leaves
forms continuous water conducting channel in all parts of the plant.
• At the root, cells in contact with soil actively take up ions. This creates difference in concentration of these
ions between root and soil. To compensate for the difference water moves into the roots from the soil.
Means, water moves into the roots creating a column of water that is pushed upwards and reaches the
leaves where photosynthesis takes place. This only is not sufficient to provide water to the whole plant.
• 2nd way- Loss of water from the aerial parts of the plant is known as transpiration. It creates a suction
which pulls water from the xylem cells of roots. Thus, helps in transport of water in plants.
• Suction- When the pressure in one part of a system is reduced relative to another, the fluid in the higher
pressure region will exert a force relative to the region of lowered pressure.
• It also Helps to maintain temperature.

33. Transpiration in Plants
• As no transpiration occurs during the night time. Thus, root pressure is the only way to convey water
to the plant (Hence, effect of root pressure is more important at night).
• During the daytime, transpiration pull is the major activity which helps to transport water to the plant.
Transport of food and other substances
• Phloem helps in transport of food in plants (also transports amino acid and other substances).
• Translocation- transport of soluble products of photosynthesis is known as translocation.
• All the products are delivered to the storage organs (leucoplast) in roots, fruits and seeds.
• Translocation of food takes place in sieve tubes with the help of adjacent companion cells in both
upward and downward direction.

34. Transpiration in Plants
• Translocation of substances in phloem is accompanied by utilising energy generated during
respiration.
• Sucrose is a naturally occurring sugar found in various amounts in plants like fruits, vegetables and
nuts. Sucrose is also produced commercially from sugar cane and sugar beets.
• Osmotic pressure is the minimum pressure which needs to be applied to a solution to prevent the
inward flow of its pure solvent across a semipermeable membrane.
• Material like sucrose is transferred into phloem tissue using energy from ATP.
• This increases the osmotic pressure of phloem tissue and causes the water to move into it.
• This pressure helps to move the material in the phloem to tissue which have less pressure. It allows
the phloem to transport material according to the plant's need. For example, in the spring sugar stored
in root and stem tissue would be transported to the buds which needs energy to grow.

35. Excretion
• Material like sucrose is transferred into phloem tissue using energy from ATP.
• Unicellular organisms release out waste products simply by diffusion.
• In human beings :- Components of excretory system
A pair of kidneys ; A pair of ureters ; A urinary bladder ; And a urethra
How is urine produced ?
Kidney located in either side of the abdomen filters waste products from the blood. Nitrogenous waste
such as urea and uric acid is removed from blood in the kidneys. Thus, urine is produced.
• Thin walled blood capillaries (Nephrons/Bowman's Capsule) filter urine in the kidney.
• As the urine flows along the tube glucose, amino acids and salts are reabsorbed.
Note:- This reabsorption doesn’t takes place in dialysis.
• Urine from the kidney is passed to the ureter then to the urinary bladder where it is stored. We have the
urge to urinat, as bladder is a muscular organ, it is under nervous control.

37. Excretion in Plants
• Plants secretes wastes in the following ways :-
I. Dead tissues can be lose by plant such as leaf.
II. Can get rid of excess water by Transpiration.
III. Many waste products are stored in vacuoles or are stored as resins or gums in old xylem.
IV. Also excretes by giving out waste products in the soil.
V. Waste products may be stored in leaves that fall off.

38. Thank You