1. The document discusses various life processes including nutrition, respiration, and transportation in organisms. It describes the modes of nutrition like autotrophic and heterotrophic, and the types of heterotrophic nutrition.
2. Nutrition in humans involves a digestive system with organs like mouth, stomach and intestines that break down food with enzymes and absorb nutrients. Respiration releases energy from food in cells with oxygen and involves aerobic and anaerobic processes.
3. Photosynthesis allows plants to produce food from carbon dioxide, water and sunlight using chlorophyll in the leaves. It is essential for life on Earth.
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Life Process Class-X
1. Prepared by:- Shivank Bhardwaj
Class:- X-G
Roll No. 38
Under Guidance of Bharti Pant Mam
2. The most important criteria to decide whether something is alive is
movement. All living things move without the help of any external help.
Some movements are easily visible like the movements of body parts.
Some movements are not easily visible like molecular movements. The
molecular movements in cells and tissues is necessary for all life
processes.
3. Life processes are the basic processes in living organisms which
are necessary for maintaining their life. The basic life processes are –
nutrition, respiration, transportation, and excretion.
i) Nutrition :– is the process of taking food by an organism and its utilization
by the body for life processes.
ii) Respiration :– is the process by which food is burnt in the cells of the body
with the help of oxygen to release energy.
iii) Transportation :– is the process by which food, oxygen, water, waste
products are carried from one part of the body to the other.
iv) Excretion :- is the process by which waste products are removed from the
body.
4. Nutrition is the process of taking food by an organism and its
utilisation by the body to build the body, for growth, to repair the
damaged parts of the body and for energy.
Life on earth depends on carbon based molecules and most of the
food are also carbon based molecules. The outside raw materials used
by living organisms are food, water and air.
1) Modes of nutrition :- There are two main modes of nutrition. They are
autotrophic nutrition and heterotrophic nutrition.
i. Autotrophic nutrition :- is nutrition in which organisms prepare their own
food from simple inorganic substances like carbon dioxide and water in the
presence of sunlight and chlorophyll.
Eg :- all green plants and some bacteria.
ii Heterotrophic nutrition :- is nutrition in which organisms get their food
directly or indirectly from plants.
Eg :- all animals fungi and some bacteria.
5. 2) Types of heterotrophic nutrition :- There are three main types of
heterotrophic nutrition. They are saprophytic, parasitic and holozoic nutritions.
1. Saprohytic nutrition :- is nutrition in which organisms get their food from
dead and decaying organisms. They break down the food material outside their
body and then absorbs it. Eg :- mushroom, bread mould, yeast, some bacteria etc.
2. Parasitic nutrition :- is nutrition in which organisms get their food from living
organisms (host) without killing them. Eg :- cuscuta, orchids, ticks, lice, leeches,
round worm, tape worm, plasmodium etc.
3. Holozoic nutrition :- is nutrition in which organisms take food directly and
then digests and absorbs it. Eg :- amoeba, paramaecium, birds, fishes, humans
etc.
6. Photosynthesis :- is the process by which plants prepare food by using
carbon dioxide and water in the presence of sunlight and chlorophyll.
The food prepared is carbohydrate which is stored in the form of
starch. Oxygen is released in this process.
Equation of photosynthesis :-
Sunlight
6CO2 + 12H2O ----------------- C6H12O6 + 6H2O + 6O2
Chlorophyll
Process of photosynthesis :-
Photosynthesis takes place in three main steps. They are :-
i) Absorption of light energy by chlorophyll.
ii) Conversion of light energy into chemical energy and splitting up of
water molecules into hydrogen and oxygen.
iii) Reduction of carbon dioxide by hydrogen to form carbohydrates.
8. Chlorophyll :- are the green pigments present in the leaves. If we
observe a cross section of a leaf under a microscope, we can see cells
containing green dot like structures called chloroplasts which contain
chlorophyll.
12. Show that chlorophyll is necessary For
photosynthesis :-
1. Take a potted plant having variegated leaves (croton plant).
Keep it in a dark room for three days so that all the starch is
used up. Then keep it in sunlight for 6 hours. Then take a leaf
from the plant and mark the green areas of the leaf on a
sheet of paper. Then dip the leaf in boiling water to make it
soft. Then dip the leaf in alcohol and heat it in a water bath
to decolourise it and remove the chlorophyll. Then wash the
leaf in water and dip it in dilute iodine solution. It will be seen
that only the green parts of the leaf turns blue black. This
shows that chlorophyll is necessary for photosynthesis.
13. 1. Take a potted plant having variegated leaves (croton plant).
Keep it in a dark room for three days so that all the starch is
used up. Then keep it in sunlight for 6 hours. Then take a leaf
from the plant and mark the green areas of the leaf on a
sheet of paper. Then dip the leaf in boiling water to make it
soft. Then dip the leaf in alcohol and heat it in a water bath
to decolourise it and remove the chlorophyll. Then wash the
leaf in water and dip it in dilute iodine solution. It will be seen
that only the green parts of the leaf turns blue black. This
shows that chlorophyll is necessary for photosynthesis.
To show that chlorophyll is necessary for
photosynthesis :-
14. I. Nutrition in amoeba :-
1. Amoeba is a unicellular animal living in water. It takes in
food by forming finger like projections called pseudopodia
and forms a food vacuole. Inside the food vacuole the food is
digested and absorbed. The undigested food is then sent out
through the surface of the cell.
15. 1. Nutrition in human beings takes place in the digestive system. It
consists of the alimentary canal and glands which produce enzymes
which breaks down food into smaller molecules.
2. The main organs of the digestive system are mouth, oesophagus,
stomach, small intestine, large intestine, and anus. The main glands
are salivary glands, gastric glands, liver, pancreas and intestinal
glands.
17. In the mouth :- the food is broken down into smaller particles by the teeth and
mixed with saliva from the salivary glands. Saliva contains the enzyme salivary
amylase which converts starch into sugar. Then the food passes through the
oesophagus into the stomach.
In the stomach :- the gastric glands produce gastric juice which contains
the enzyme pepsin, hydrochloric acid and mucous. Pepsin breaks down proteins.
Hydrochloric acid makes the medium acidic and helps in the action of pepsin.
Mucous protects the walls of the stomach from the action of the acid. Then the
food passes into the small intestine.
In the upper part of the small intestine called duodenum :- the food is
mixed with bile from liver and pancreatic juice from the pancreas. Bile breaks
down fats into smaller globules. Pancreatic juice contains the enzymes trypsin
and lipase. Trypsin breaks down proteins and lipase breaks down fats.
In the small intestine :- the glands the walls of the small intestine produces
intestinal juice. The enzymes of the intestinal juice coverts carbohydrates into
glucose, fats into fatty acids and glycerol and proteins into amino acids. The walls
of the small intestine has several finger like projections called villi having blood
vessels. It helps to increase the surface area for the absorption of digested food.
The digested food is absorbed by the blood and transported to all cells in the
body. Then the undigested food passes into the large intestine.
In the large intestine :- water is absorbed and the waste material is
removed through the anus.
18. 1. Respiration is the process by which food is burnt in the cells of the
body with the help of oxygen to release energy. It takes place in the
mitochondria of the cells.
2. The energy released during respiration is used to make ATP
molecules (Adenosine tri phosphate) from ADP molecules (Adenosine
di phosphate) and inorganic phosphate.
Energy
ADP + Phosphate ATP
Respiration
3. Energy is stored in the cells in the form of ATP molecules. When the
cells need energy, ATP is broken down in the presence of water to form
ADP and energy is released.
Water
ATP ADP + Energy
19. b) Types of respiration :-
There are two main types of respiration. They are aerobic and
anaerobic respiration.
I Aerobic respiration :- takes place in the presence of oxygen. It produces
more energy. The end products are carbon dioxide, water and energy. It takes
place in most organisms.
II In aerobic respiration glucose is converted into pyruvate in the cytoplasm in
the presence of oxygen and then in the presence of oxygen, pyruvate is converted
into carbon dioxide, water and energy in the mitochondria.
presence of oxygen presence of oxygen
Glucose Pyruvate CO2 + H2O + Energy
cytoplasm mitochondria
20. ii) Anaerobic respiration :- takes place in the absence of oxygen. It
produces less energy. The end products are lactic acid or ethanol,
carbon dioxide, and energy. It takes place in muscle cells and yeast.
In anaerobic respiration in muscle cells, glucose is converted into
pyruvate and in the absence of oxygen pyruvate is converted into
lactic acid and energy.
presence of oxygen absence of oxygen
Glucose Pyruvat Lactic acid + Energy
cytoplasm muscle cells
In anaerobic respiration in yeast, glucose is converted into pyruvate
and in the absence of oxygen pyruvate is converted into ethanol,
carbondioxide and energy. This process is called fermentation.
presence of oxygen absence of oxygen
Glucose Pyruvate Ethanol + CO2 + Energy
cytoplasm yeast
22. The main organs of the respiratory system are
nostrils, nasal cavity, pharynx, larynx, trachea,
bronchi, bronchioles, lungs and diaphragm.
23. 1. Air enter through the nostrils. The hairs and mucous traps the
dust particles. It then passes through the phraynx, larynx, trachea,
bronchi and enters the lungs. The trachea has rings of cartilage
which prevents it from collapsing when there is no air in the
trachea. The bronchi divides into smaller tubes called bronchioles
which ends in tiny air sacs called alveoli. The alveoli is supplied
with blood vessels through which exchange of gases takes place.
The alveoli helps to increase the surface area for the exchange of
gases.
24. Mecahanism of breathing :-
1. When we breathe in air, the muscles of the diaphragm contracts
and moves downward and the chest cavity expands and air enters
into the lungs.
2. When we breathe out air, the muscles of the diaphragm relaxes and
moves upward and the chest cavity contracts and air goes out of
the lungs.
25. 8) Transportation :-
a) Transportation in Humanbeings :-
The main transport system in human beings is the circulatory
system. It consists of blood, arteries, veins capillaries and heart.
i) Blood :- transports food, oxygen and waste products. It consists of
plasma, red blood cells (RBC), white blood cells (WBC) and platelets.
Plasma transports food, water, carbondioxide, nitrogenous waste etc.
Red blood cells transports oxygen. White blood cells kills harmful
microbes and protects the body. Platelets help in clotting of blood and
prevents loss of blood during injury.
ii) Arteries :- carry pure blood from the heart to all parts of the body.
They are thick walled and do not have valves.
iii) Veins :- carry impure blood from all parts of the body to the heart.
They are thin walled and have valves.
iv) Capillaries :- are very narrow blood vessels which connects
arteries and veins together. The exchange of food, water, oxygen,
carbon dioxide etc. between the blood and cells take place through
the capillaries.
26. Heart :- is a muscular organ which pumps blood to all parts of the body. It has
four chambers. The upper chambers are called atria and the lower chambers are
called ventricles. Since the ventricles pump blood to the different organs its walls
are thicker than the atria. The right and left chambers are separated by a septum.
It prevents the mixing of oxygenated and deoxygenated blood The atria and
ventricles have valves between them to prevent blood flowing backward.
28. Working of the heart ( Circulation of blood ) :-
When the left atrium relaxes oxygenated blood from the lungs flows into it
through the pulmonary vein. When it contracts, the left ventricle expands and the
blood flows into it. Then the left ventricle contracts and the oxygenated blood is
pumped out through the aorta to all parts of the body. After circulating through all
parts of the body the deoxygenated blood enters the right atrium through the vena
cava. When the right atrium contracts, the right ventricle expands and the blood
flows into it. Then the right ventricle contracts and the blood is pumped to the
lungs through the pulmonary artery. In the lungs carbon dioxide is removed and
oxygen is absorbed and the oxygenated blood again enters the left atrium and the
process repeats.
Since blood flows through the heart twice in one cycle, it is called double
circulation.
Lymph :- is a colourless fluid present in intercellular spaces. It is formed from
the plasma which escapes from the capillaries. Lymph drains into lymphatic
capillaries which forms lymph vessels and joins into large veins.
Lymph transports digested fats and drains excess fluids from intercellular
spaces back into the blood. It contains lymphocytes which kills germs and
protects the body
29. i) The heart in mammals :- and birds have four chambers and the right and
left sides of the heart is separated by a septum. This prevents mixing of
oxygenated and deoxygenated blood and provides efficient supply of
oxygen. This is necessary because they need more energy to maintain their
body temperature.
ii) The heart in amphibians and reptiles :- have three chambers and allows
some mixing of oxygenated and deoxygenated blood because the do not use
energy to maintain their body temperature. Their body temperature is the same
as the temperature of the surroundings.
iii) The heart in fishes :- have only two chambers and blood is oxygenated in
the gills.
31. In plants, transportation of materials like food, water and minerals
takes place through conducting tissues called xylem and phloem.
i) Xylem :- transports water and minerals from the roots to all parts of the plant.
It consists of xylem vessels and tracheids. Water and minerals enter the roots by
diffusion. Then due to transpiration, the suction force helps in the upward
movement of water an minerals.
32. ii) Phloem :- transports food from the leaves to the other parts of the plant. This
process is called translocation. The phloem consists of sieve tubes and
companion cells. Food from the leaves is transferred to the xylem by the energy
of ATP molecules. Due to osmotic pressure water enters the phloem and helps in
the transport of food.
33. 1. Excretion is the process by which the waste products
produced during metabolic activities is removed from the body.
2. In unicellular organism the waste products are removed from the
cells into the surroundings by diffusion.
3. In multicellular organisms the waste prducts are removed through
specialised organs.
34. Excretion in Human beings :-
I The excretory system consists of a pair of kidneys , a pair of
ureters, urinary bladder and urethra. Each kidney has a number of
excretory units called nephrons.
36. Nephron :-
Each nephron has a cup like structure called Bowman’s capsule containing a
bundle of capillaries called glomerulus. The Bowman’s capsule leads into a
tubular structure which joins into a collecting duct. The renal artery brings the
nitrogenous waste like ammonia, urea, uric acid (urine) along with excess water,
salts etc. into the nephron. It filters the nitrogenous waste, water and salts which
passes through the tubular structure into the collecting duct. The waste then
passes through the ureters into the urinary bladder and is then sent out through
the urethra as urine.
The useful products like amino acids, glucose, salts etc. are reabsorbed by the
capillaries around the tubular structure and goes into the real vein.
b) Excretion in plants :-
In plants the gaseous waste products produced during respiration (CO2) and
photosynthesis (O2) are removed through the stomata. Excess water is removed
through the stomata. This process is called transpiration.
Some waste products are stored in the leaves and removed when the leaves dry
and fall off. Some waste products are stored in vacuoles. Some waste products
like gums and resins are stored in the old xylem cells. Some waste products are
removed through the roots.
38. MCQ - QUESTIONS
Q-1 A gland not associated with alimentary canal is :-
A Liver C Pancreas
B Salivary Gland D Adrenal
Q-2 A bio-chemical compound that readily combines with oxygen and
distributes it throughout stomata is called :-
A Water C HB
B Urea D Acetylcholine
39. Q-3 The process in which loss of water takes place in the form of
water vapours through stomata is called :-
A Transportation C Guttation
B Transpiration D Translocation
Q-4 B.P. Is measured by instrument called :-
A Barometer C Manometer
B Sphygmomanometer D photometre
Q-5 Filteration units of Kidney are :-
A Ureter C Neurons
B Urethra D nephrons
Q-6 The opening and closing of stomatal pore depends upon :-
A oxygen C concentration of CO2 units
B temperature D water in guard cells
40. Q-7 Autotrophic organisms include :-
A bacteria and virus B bacteria and fungi
C green plants and some bacteria D green plants and all
bacteria
Q-8 which of the following is chiefly digested in the stomach :-
A carbohydrates B Proteins
C Lipids D Fats
Q-9 in a closed circulatory system blood is enclosed with :-
A vessels B heart
C skeleton D sinuses
41. Q-10 large intestine carries out :-
A absorption B assimilation
C digestion of fats D digestion of carbohydrates
Q-11 normal blood pressure :-
A 120/80 mm of Hg C 120/60 mm of Hg
B 160/80 mm 0f Hg D 180/80 mm of Hg
42. In the following questions, a statement of Assertion is followed by a
statement of Reason. Mark the correct choice as :-
(a)If both Assertion and Reason are true, and Reason is the correct
explanation of Assertion
(b) If both Assertion and Reason are true but Reason is not the correct
explanation of Assertion
(c) If Assertion is true, but Reason is false
(d) If Reason is true, but Assertion is false
(e) If both Assertion and Reason are false
43. Q-1 Assertion: Lungs always contain a residual volume of air.
Reason: It is so to ensure enough time for the release of CO2 and for the absorption of
O2 .
Q-2 Assertion: In a healthy adult, the initial filtrate in the kidneys is about 180 L daily,
but the actual volume excreted is only a litre a day.
Reason: Most of the filtrate is lost from the body in the form of sweat.
Q-3 Assertion: Respiration is opposite of Photosynthesis
Q-4 Reason: In Photosynthesis food is made from energy and in Respiration food is
converted to energy.
Q-5 Assertion: The four chambered heart does not mix oxygenated and deoxygenated
blood.
Reason: Four chambered heart is found in mammals with advanced body functions.
Q-6 Assertion: Translocation of food occurs in Plants.
Reason: Xylem tissue is responsible for Translocation.
44. 3 Marks-Questions
Q-1 Mention the two main components of the transport system in plants.
State one function of each one of these components ?
Q-2 State the function of guard cells. What will happen to guard cells and stomatal pore
when water flows to guard cells ?
Q-3 Give reason –
(i) The two ventricles have thicker muscular walls than the two atria in human heart.
(ii) The capillaries have walls which are one-celled thick.
Q-4 (i) Name two organisms that obtain food through parasitic nutritive strategy,
(ii) How do fungi obtain their food ?
Q-5 Give reasons for the following :
(i) Glottis is covered by epiglottis
(ii) Lung alveoli are covered with blood capillaries
(iii) The wall of trachea is supported by cartilage rings.
45. 5-Marks-Questions
Q-1 In single celled organisms, diffusion is sufficient to meet all their requirements of
food, exchange of gases or removal of wastes but it is not in case of multicellular
organisms. Explain the reason for this difference.
Q-2 Name three life processes which are essential for maintaining life and briefly explain
the functioning of any one of them.
Q-3 Explain the process by which the energy requirements of the autotrophic organisms
are fulfilled. In which form the unused carbohydrates get stored ?
Q-4 (a) List three events that occur during the process of photosynthesis. State in brief
the role of stomata in this process.
(b) Describe an experiment to show that sunlight is essential for photosynthesis.
Q-5 How do the guard cells regulate opening and closing of stomatal pores ? Explain
with the help of diagram. Also indicate what happens to the rate of photosynthesis if
stomata get blocked due to dust
46. 1. ADRENAL
2. HB
3. TRANSPIRATION
4. SPHYGMOMANOMETER
5. NEPHRONS
6. WATER IN GUARD CELLS
7. GREEN PLANTS AND SOME BACTERIA
8. PROTEINS
9. VESSELS
10. ABSORPTION
47. ANS-1
Single celled organisms are in direct contact with the environment so that
diffusion is helpful to them in exchange of gases, removal of wastes and even
meeting their requirement of food. However, in most * multicellular organisms,
the body is covered by dead cells. Cell to cell diffusion is unable to meet the
requirement of all body cells. For example, in humans cell to cell diffusion will
take three .years to send oxygen from lungs to toes. Multicellular organisms
have developed specialised structures for performing different functions, e.g.,
digestive tract, respiratory surface, excretory organs. These structures are
connected to all body cells through a transport system, e.g., circulatory system
in animals, xylem and phloem in plants. The transport system is quite fast to
bring materials to and from the cells
5-MARKERS
48. ANS-2
Nutrition, respiration, exchange of materials.
Nutrition: It is the process by which living beings procure food for obtaining
energy and body building materials. Body building materials are usually carbon-
based. The food sources are also carbon based. They are, of course, varied.
Plants manufacture their own food in the process of photosynthesis. Animals
obtain food from outside. Food obtained from outside is first broken down
through digestion into simpler soluble substances for absorption. Inside the
cells, the simple substances are converted into various complex biochemicals
to form components of protoplasm. Some biochemicals function as respiratory
substfates
49. ANS 3
Photosynthesis. It occurs in the following steps :
1.Photolysis: With the help of light energy, oxygen evolving Z-complex splits up
water into its components — protons (H+), electrons (e–) and oxygen.
2.Absorption of Light Energy: Chlorophyll absorbs light energy.
3.Primary Reaction: Chlorophyll converts the absorbed light energy into
chemical energy. It is called primary reaction of photosynthesis. It builds up ATP
with the help of excited electrons.
4.Formation of Reducing Power: Coenzyme NADP+ is changed to reduced form
of NADPH.
5.Reduction of CO2: Carbon dioxide is reduced enzymatically with the help of
ATP to form carbohydrates.
Storage: Starch.
50. Three Events of Photosynthesis: Information is transmitted from one plant cell
to another through plasmodesmata and hormones.
Role of Stomata in Photosynthesis. Inward diffusion of carbon dioxide and
outword diffusion of oxygen.
(b) Sunlight is Essential for Photosynthesis: It is the source of energy for
photosynthesis. Light is visible part of the electromagnetic radiations. It has a
wavelength of 390-760 nm. Photosynthetically active radiations or PAR are
400-700 nm. Natural source of light is sun but artificial light can also provide
energy to plants for their photosynthesis. Plants absorb light mostly in violet-
blue and red parts of visible light. Violet-blue light carries more energy as
compared to red light. Plants growing under shade of others receive mostly
green and some violet light. They have lower rates of photosynthesis.
Light has two functions, photolysis of water and excitation of chlorophyll to emit
electrons. Photolysis of water produces oxygen, protons and electrons.
Electrons and protons (Hydrogen ions) help in producing ATP and NADPH2,
popularly called assimilatory power.
Answer-4
51. Re
Ans-5
Regulation of Stomatal Pore:
Opening and closing of stomata is regulated by gain or loss of turgidity of their guard
cells. During opening of stomata, guard cells withdraw K+ ions from surrounding
epidermal cells, followed by absorption of water from them. As a result, guard cells swell
up and become turgid. Their outer thin and elastic walls bend outwardly followed by
outward movement of thicker inner walls. The latter creates a pore in between the two
guard cells.
During closure movement of stomata, guard cells send out K+ ions. Water also passes
out. Guard cells become flaccid. Their inner thick walls come to touch each other. The
stomatal pore gets closed.
Blocking of Stomata:
1.Photosynthesis will be reduced,
2.There will be no gaseous exchange and transpiration. As a result leaves will burn up in
hot summer sun.
52. 3-MARKERS
ANS 1 Transport system of plants consists of two main
components, xylem and phloem. Xylem (through vessels and
tracheids) takes part in conduction of sap mostly in the upward
direction. Phloem (through sieve tubes) transports food
marterials both in upward and downward directions
ANS 2 Function of Guard cells : Opening, closing and regulating
the stomata or stomatal pores.
Flow of Water : Passage of water into guard cells will make
them turgid. The turgid guard cells bend is such a way as to
open the stomatal pore
53. ANS-3 (i) Atria are to receive blood from veins and pump the
same into adjacent ventricles only. They have, therefore, thin
walls. Ventricles are to pump blood into arteries forcefully as it
is to be sent to lungs (right ventricle) and all parts of the body
(left ventricle). Therefore, walls of ventricles are thick and
muscular with those of left ventricle being thicker.
(ii) Capillaries take part in exchange of materials (nutrients,
wastes, gases) between blood and tissue fluid.
Ans - 4
(i) Parasitic Nutrition. Cuscuta (a plant), Plasmodium (Malarial
Parasite)
(ii).Most of the fungi are saprotrophs. They obtain their
nourishment from organic matter.
54. Ans-5 (i) Epiglottis. To prevent entry of food and water during
swallowing.
(ii) Lung Alveoli. Lung alveoli constitute the respiratory surface
of the lungs. Their walls have rich supply of blood for gaseous
exchange, i.e. passage of oxygen from alveolar air to blood and
passage of carbon dioxide from blood to alveolar air.
(iii) Tracheal Rings (C-shaped). For providing support,
preventing collapse of trachea and allowing for uninterrupted
flow of air.