v Criteria of life- (i) Growth
(ii) Movement
v Nutrition- The process in which an organism takes in food, utilizes
it to get energy, for growth, repair and maintenance, etc. and excretes the
waste materials from the body.
v Types of nutrition
1.
Autotrophic nutrition(Auto =self: trophos =
nourishment) E.g. Plants, Algae, blue green bacteria.
o Process – Photosynthesis(Photo=light; Synthesis= to combine)
o Raw materials- (i) Carbon dioxide (ii)Water
o
Equation- sunlight
o 6CO2 + 6H2O C6H12O6
+ 6O2
Chlorophyll
o Energy conversion- Light/Solar energy to Chemical energy
o Role off Chlorophyll- To trap the sun’s energy for photosynthesis
o Factors- (i) Carbon dioxide (ii) Water(iii) Light (iv)
Temperature
o Events/ Steps of photosynthesis-
(i)
Absorption of light energy by
chlorophyll
(ii)
Conversion of light energy to
chemical energy & Splitting of water molecule into Hydrogen & oxygen
(iii)
Reduction of Carbon dioxide to
Carbohydrate
o Gaseous exchange- (i) Gas used- Carbon dioxide
(ii) By product - Oxygen
o Source of raw materials-
(i)
Carbon dioxide –Land plants- Air, Aquatic
plants- Water
(ii)
Water & Minerals - Soil
2. Heterotrophic nutrition (Hetero
=others: trophos = nourishment) Eg.
Animals, plants lacking chlorophyll like fungi.
(a)
Saprophytic nutrition: Organisms feeds on dead decaying plants or animals material. E.g.
Fungi, Bacteria
(b) Parasitic nutrition: Organisms
obtain food from the body of another living (host)
o Endoparasite : Parasite lives inside the body of the host e.g.
tapeworm, roundworm.
o Exoparasite: Parasite lives
on the body of the host. E.g. lice, leech.
Note- The parasite benefits while the host is
usually harmed e.g. Cuscutta-plant parasite (amar bel), plasmodium (malarial
parasite).
(c) Holozoic
nutrition: Organism (mostly animals) take in whole food and then digest it
into smaller particles with enzyme. Eg. Amoeba, Paramoecium. Animals, human
beings.
o Steps in Holozoic nutrition
(i)
Ingestion: taking in of food.
(ii)
Digestion: breaking down of
complex food into simpler, absorbable form.
(iii)
Assimilation: Utilization of
digested food from the body.
(iv)
Egestion: Removing undigested
food from the body
o Nutrition in human beings
§ Alimentary canal-
Mouth → Oesophagus → Stomach → Small
intestine → Large intestine
§ Important gland/juices
(Refer to figure 6.6 page no.97 of
N.C.E.R.T Text book)
Organ
|
Gland
|
Enzyme/Juice
|
Function
|
Mouth
|
Salivary glands
|
Salivary Amylase
|
Converts starch into sugar
|
Stomach
|
Gastric glands
|
Gastric juice-
(i) Hydrochloric
acid →
(ii)
Pepsin →
(iii) Mucus →
|
(a) Kills harmful bacteria that
enters with the food.
(b)
Makes the medium alkaline
for the action of Pepsin
Digests proteins
Protects the inner lining of the stomach
from the corrosive action of Hydrochloric acid.
|
Small intestine
|
1) Liver
2)
Pancreas
|
(i) Bile juice →
(ii)
Pancreatic
Juice
|
(a) Makes the medium acidic
for the action of Pancreatic
enzymes.
(b) Breaks down large fat
molecules into smaller globules
so that enzymes can act upon
them.
Converts Carbohydrates to glucose
Converts Proteins to Amino acids
Converts Fats into Fatty acids &
Glycerol
|
§ Peristaltic movements- Rhythmic contraction of muscles of the lining
of Alimentary canal to push the food forward.
§ Sphincter muscle- Helps in the exit of food from the stomach.
§ Villi- Small finger like projections on the walls of-
(v)
Small intestine- To increase
the surface area for the absorption of food.
(vi)
Large intestine- For absorption
of water.
v Respiration- The process by which
digested food is broken down with the help of Oxygen to release energy.
o Types of respiration- (i)
Aerobic respiration (ii)Anaerobic
respiration
Aerobic respiration
|
Anaerobic respiration
|
1.
Takes place in presence of Oxygen.
2.
End products- Carbon dioxide & Water
3. More energy is released.
4.
Takes place in Cytoplasm & Mitochondria
5. Complete oxidation of glucose takes
place.
6. It occurs in most organisms.
7.
Equation-
Glucose→ Pyruvate→ CO2 + H2O
+ Energy
|
1.
Takes place in absence of Oxygen.
2. End products- Ethanol & Carbon
dioxide
3. Less energy is released.
4.
Takes place in only in Cytoplasm.
5. Incomplete oxidation of glucose takes
place.
6.
It occurs in certain bacteria, yeast & certain tissues of higher
organisms. E.g. In humans during vigorous exercise, when the demand for
Oxygen is more than the supply, muscle cells respire anaerobically for some
time.
7.
Equation-
In Yeast-
Glucose→ Pyruvate→ Ethanol + H2O
+ Energy
In muscle cells -
Glucose→ Pyruvate→ Lactic acid + Energy
|
- Some common features of Respiratory organs- (i) Large surface area- for greater rate of diffusion of respiratory gases. (ii) Thin permeable walls – to ensure easy diffusion & exchange of gases. (iii) Extensive blood supply- Respiratory organs are richly supplied with blood vessels for quick transport of gases.
- Gaseous exchange in plants-
- Process – Diffusion
- Direction of diffusion depends on- (i) Environmental conditions
(ii) Requirement of the plant.
§ Day time- Carbon dioxide given out during respiration is used for
photosynthesis. Therefore only Oxygen is released, which is a major activity
during the day.
§ Night time – Only respiration takes place. Therefore only Carbon
dioxide is released, which is a major activity during the night.
- Gaseous exchange in animals-
§ Terrestrial animals- take Oxygen from the atmosphere.
§ Aquatic animals- take Oxygen dissolved in water. (Oxygen content is
low in water, therefore they breathe faster.
- Human Respiratory system- External nostrils → Nasal cavity → Trachea→ Bronchi → Bronchioles →Alveoli
§ Rings of cartilage present in the throat ensure that the trachea (air
passage) does not collapse when there is less air in it.
§ Lungs – (i) Present in the thoracic cavity.
(ii) They are spongy, elastic bags consisting of
Bronchi,
Bronchioles
and Alveoli
Refer to figure
6.9 page no. 104 of N.C.E.R.T Text book)
- Respiration occurs in two phases-
- (i) External-Breathing, which is a mechanical process. (ii) Internal - Cellular respiration
- Mechanism of breathing – It includes : (i)Inhalation (ii) Exhalation
- Exchange of gases-
§ Unicellular organisms- By Diffusion
§ Animals- (i) As the body size is large, diffusion alone is not
enough.
(ii) Respiratory pigments also required.
(iii) Respiratory pigment
in human beings is Haemoglobin,
which is present
in red blood corpuscles.
(iv) It has very high affinity for
Oxygen.
(iv) Carbon dioxide is
more soluble in water thanOxygen, so it
Gets dissolves
in blood and is thus transported.
v Transportation
- Transportation in human beings-
§ Blood- (i) It is a fluid connective tissue.
(ii) Components- (1) Fluid medium- Plasma
(2) Red blood corpuscles
(3) White blood corpuscles
(4) Platelets suspended in plasma
(iii) Plasma transports food, Oxygen, Carbon dioxide,
Nitrogenous wastes, etc.
§ Functions of blood- (i) Transport of respiratory gases.
(ii) Transport of
nutrients.
(iii) Transport of
waste products.
(iv) Defence against infection
§ Blood vessels- (i) Arteries (ii) Veins (iii) Capillaries
Arteries
|
Veins
|
1.
Thick walled.
2.
Deep seated.
3.
Carry blood away from the heart.
4.
Carry Oxygenated blood.
5.
Valves absent.
|
1.
Thin walled.
2.
Superficial.
3.
Carry blood to the heart.
4. Carry Deoxygenated blood.
5.
Valves present
|
§
Heart- (Refer to figure 6.10 page no. 106 of
N.C.E.R.T Text book)
(i) It is a muscular organ, which works
as a pump in the circulatory system.
(ii) It is the size of our fist.
(iii) It has two sides, which are separated by a
partition so that the oxygenated and
deoxygenated
blood do not get mixed up.
(iv) It has four
chambers-
Two upper chambers called Atria.
Two lower chambers called
Ventricles.
§ Working of heart-
Left side-
(i) Left atrium relaxes & the Oxygenated
blood enters it from
the lungs through the pulmonary vein.
(ii)
Left atrium contracts & the blood enters the left ventricle
through the valve.
(iii) Left Ventricle contracts and the blood
is pumped into the
largest artery ‘Aorta’ and is
carried to all parts of the body.
Right side- (i) Right atrium relaxes & the deoxygenated blood from the
body enters it
through superior and inferior Vena cava.
(ii)
Right atrium contracts & the blood enters the right Ventricle
through
the valve.
(iii) Right Ventricle contracts and the blood is pumped into the
Pulmonary
artery and
is carried to lungs.
§ Valves- Unidirectional to prevent the backward flow of blood.
§ Pulmonary vein is the only vein that carries Oxygenated blood.
§ Aorta is the only artery that carries Deoxygenated blood.
§ Double circulation in man- because the blood passes through the
heart twice in one complete cycle of the circulation.
§ Capillaries- (i) Form the connection between arteries & veins.
(ii)
Walls are one cell thick only for easy exchange of
blood.
§ Platelets- Plug the leaks of arteries and veins by clotting the
blood.
§ Lymph- Extracellular fluid similar to plasma but colourless with
lesser protein.
§ Function of lymph- (i) Transportation
of digested & absorbed fats from
the
small intestine.
(ii) Drains excess fluid from the
intercellular spaces
back in the blood.
§ Higher animals- E.g., birds,
mammals.
(i)
Oxygenated blood & Deoxygenated blood are
completely separate for efficient Oxygen supply.
(ii)
This is to fulfil higher energy needs and to maintain
body temperature (warm blooded animals).
§ Amphibians & reptiles- have 3 chambered heat where little mixing
of Oxygenated blood & Deoxygenated
blood takes place. Therefore their body temperature varies with the temperature
of the environment. (cold blooded animals)
- Transportation in plants-
§ Plants need less energy needs- because they do not move and
therefore have a slow transport system
§ Transport of water-
(i)
Takes place by xylem tissue
present in roots, stem, leaves and is therefore interconnected.
(ii)
Root cells take up ions from
the soil, which creates a concentration difference between root and soil.
Column of water therefore rises upwards.
§ In very tall plants- transpiration creates a suction pressure, which
pulls the water upwards.
§ Importance of transpiration-
(i)
Helps in upward movement of
water in plants.
(ii)
It regulates the temperature in
plants.
§ Transport of food-
(i)
Takes place by phloem tissue.
(ii)
Movement of prepared food in
plants is called translocation.
v Excretion- The biological process of removal of harmful metabolic
wastes in living organisms.
v Excretion in human beings-
(Refer
to figure 6.13 page no. 110 of N.C.E.R.T Text book)
§ Organs of excretory system- (i) Kidneys (iii) Urinary bladder
(ii) Ureters (iv) Urethra
§ Kidneys-
(i)
Two in number
(ii)
Bean shaped
(iii)
Present in abdomen on either
side of the backbone
(iv)
Basic unit is nephron.
a.
Glomerulus- Group of
capillaries (cluster) present in Bowman’s capsule to receive
blood from renal artery and filters it.
b.
Bowman’s capsule- Cup shaped
structure, which contains glomerulus.
c.
Convoluted tubule-is long and reabsorbs vital
nutrients like glucose, amino acids, salts, urea and water.
Note-Vital functions of kidneys- (a) Filtration & removal of
Nitrogenous wastes
(b) Reabsorption of vital nutrients
§ Ureters- Transport the urine formed in the kidneys to the urinary
bladder.
§ Urinary bladder- Muscular bag like structure to store urine.
§ Urethra- Helps in removal of urine when the Urinary bladder is full.
§ Artificial kidney- Principle: Dialysis
v Excretion in plants-
- Gaseous wastes- CO2 in respiration & O2 in photosynthesis are removed by the process of diffusion.
- Excess water- is removed by transpiration.
- Other wastes- (i) Stored in cellular vacuoles or in leaves, which fall off or as gums, resins, etc. in old xylem.
(ii) Excreted in soil.
v Important diagrams-
1.
Open & close stomata
2.
Steps of nutrition in Amoeba
3.
Alimentary canal of human
beings/ Digestive system of human beings
4.
Respiratory system of human
beings
5.
Structure of heart.
6.
Excretory system of human
beings
7.
Structure of nephron
v Important activities-
1.
To prove that chlorophyll is
necessary for photosynthesis. Watch
Searches related to life process notes for class 10
CBSE Biology class 10 Key
notes prepared by KVS and Delhi Schools for SA-01
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