The document discusses the key life processes that occur in living organisms. It describes 5 main life processes: nutrition, respiration, excretion, growth and repair, and reproduction. Nutrition involves taking in energy from external sources through processes like photosynthesis in plants and digestion in animals. Respiration breaks down nutrients through cellular respiration to release energy. Excretion eliminates waste. Growth and repair involve cellular division and regeneration. Reproduction ensures continuation of the species through processes like ovulation, fertilization, and embryonic development.

1. LIFE PROCESS
By Pinky Rathee
M.Sc. Nursing

2. LIFE PROCESSES
The maintenance
functions which are
happening inside
our body and
inside the body of
all the living
organisms to
maintain the living
being are life
processes.

3. Life processes comprises of
the following functions:-
Nutrition
Respiration
ExcretionGrowth and
repair
Reproduction

5. 1. NUTRITION
It is the process of getting energy from
outside sources.
Next process of nutrition is to break-
down these sources to release energy.
Process of getting nutrition can vary
from organism to organism and is
affected by the external environment.

6. BASED ON MODE OF GETTING
FOOD ORGANISM CAN BE
CLASSIFIED AS FOLLOWS-
Autotrophs
Heterotrophs

7. Autotrophs-makes
their own food. All
green plants are
autotrophs. The
process of food
preparation in plant is
called photosynthesis.
It involves making of
glucose with the help of
carbondioxide and
water in presence of
sunlight.

8.  Chemical reaction-
6CO2 + 6H2O → C6H12O6 + 6O2
Carbondioxide + Water → Glucose + Oxygen
 Glucose thus formed is used
by the plants to satisfy its energy needs. The excess amount
is stored as starch in
various parts of the plants.

9. Hetrotrophs-
Those organisms which are dependent on other
organism for their food are called heterotrophs.
Some animals, like humans have complex digestive
system to break the food into basic constituents to make
them fit for oxidation.
Certain organisms break the food into basic molecules
outside their body then absorb them. Fungi use some
enzymes to break the food outside their body.
Some organisms take food from other organisms without
killing them. Most of the parasites take nutrition in this
way.

10. Human digestive system-
carries out following
functions:-
• Intake of food
• Digestion of food
• Assimilation of food
• Expulsion of waste products

12. Respiration
Breaking down of nutrients to release energy is
respiration. A complex series of oxidation-reduction
goes inside the cell to burn food to produce energy.
This energy is used to carry out different activities
inside a living organisms.

13. Respiration
Chemical reaction-
C6H12O6 + 6O2 → 6 CO2 + 6H2O + 674 Kcal
• Oxygen is required for oxidation of
glucose during cellular respiration.

14. Respiration
 In plants and smaller animals this oxygen gets
inside the organism by simple mechanism way
called osmosis or by difference in air pressure.
 But in larger organisms complex system is needed
to carryout transportation of oxygen inside the
body and carbon-dioxide out of the body. This
process is called external respiration and is
different from cellular respiration.

16. EXCRETION
 Expulsion of harmful substances, which are by-
products of life processes, is called excretion.
 In body human body many organs help in excreting
harmful substances out of the body. Lungs expel
carbon dioxide, skin expels some waste through
spit, and rectum expels waste through faeces. Main
excretory organ in the human body is kidney.
Kidney filters hormonal substances from blood and
expels them through urine.

17. GROWTH AND REPAIR
 Genetics and cellular division.

18. STAGES ARE PROPHASE, METAPHASE, ANAPHASE, AND
TELOPHASE. DURING MITOSIS, THE CHROMOSOMES, WHICH
HAVE ALREADY DUPLICATED, CONDENSE AND ATTACH TO
SPINDLE FIBERS THAT PULL ONE COPY OF EACH
CHROMOSOME TO OPPOSITE SIDES OF THE CELL. THE RESULT
IS TWO GENETICALLY IDENTICAL DAUGHTER NUCLEI.

19. MEIOSIS IS THE PROCESS BY WHICH THE NUCLEUS DIVIDES IN
ALL SEXUALLY REPRODUCING ORGANISMS DURING THE
PRODUCTION OF SPORES OR GAMETES. THESE CELLS HAVE A
SINGLE SET OF CHROMOSOMES AND ARE CALLED HAPLOID, AS
OPPOSED TO DIPLOID CELLS WITH TWO SETS.

21. REPRODUCTION
 Ovulation
 At puberty, ova begin to mature. During a period
known as follicular phase, an ovum enlarges as a
type of cyst called graafian follicle until it reaches
the surface of ovary where transport occurs. The
ovum (oocyte) is discharge into the peritoneal
cavity. This periodic discharge of matured ovum is
referred to as ovulation.

22. REPRODUCTION

23. REPRODUCTION
 The ovum usually finds its way into the fallopian
tube, where it is carried to the uterus.
 If it meets a spermatozoon, the male reproductive
cell, a union occurs and conception takes place.
 After the discharge of ovum, the cells of the
graafian follicle undergo a rapid change.
 Gradually, they become yellow (corpus leuteum)
and produce progesterone, a hormone that
prepares the uterus for receiving the fertilized
ovum.
 Ovulation usually occurs 2 weeks prior to the next
menstrual period.