3. Nutrition in different lower
animals like
Nutrition in Amoeba
Nutrition in Hydra
Nutrition in Planaria
4. Nutrition also
called nourishment or aliment is the
provision, to cells andorganisms, of the
materials necessary (in the form of
food) to support life.
Many common health problems can be
prevented or alleviated with a healthy
diet.
5. Nutrition: The process of intake of food and
its conversion into living protoplasm in cells.
• Autotrophs- Organisms which can prepare
their food
• Heterotrophs- Organism which cannot prepare
their own food due to lack of chlorophyll.
6. It is the nutrition obtained by
digesting organic compounds.
Animals, fungi, many prokaryotes and
protoctists are unable to synthesize
organic compounds to use as food,
They are called heterotrophs
7. Types of Heterotrophic Nutrition
Holozoic nutrition
Complex food is taken into a specialist digestive
system and broken down into small pieces to be
absorbed.
Saprotrophitic nutrition
Organisms feed on dead organic remains of
other organisms.
8. Parasitism
Organisms obtain food from other living
organisms (the host), with the host receiving
no benefit from the parasite.
Mutualism
A symbiotic relationship between organisms,
with each contributing and benefiting from
each other.
9. Holozoic nutrition (Gr. holo, whole + zoikos, of
animals) is a method of nutrition that involves the
ingestion of liquid or solid organic material,
digestion, absorption and assimilation of it to
utilize it.
This method suggests phagocytosis where the cell
membrane completely surrounds the food
particle(engulfing of food material)
11. Unicellular
Freshwater organism
Microphagus Feeder
Intracellular digestion
Its diet includes bacteria, microscopic plants like the diatoms,
minute algae, microscopic animals like other protozoa, nematodes
and even dead organic matter.
Amoeba does not have any specialized structure or organ for the
process of nutrition.
It takes place through the general body surface with the help of
pseudopodia
13. Structure of Amoeba
The amoeba belongs to the kingdom Protista
. The name amoeba comes from the greek word amoibe, which means
change.
The amoeba is a single celled microscopic organism (about 0.3 mm across).
It has cytoplasm, nucleus, cell membrane and a variety of inclusions in the
cytoplasm and exhibits all the essential functions of any living organism.
They are found in fresh water (like puddle and ponds), salty water,
wet soil and in animals.
14. Structure of Amoeba (cont…)
Cell membrane: The cell membrane is flexible and porous. It allows the amoeba to
change shape.
Cytoplasm: Cytoplasm is the living substance which contains all the chemical
reactions necessary for life.
.Nucleus: A large, disk-shaped nucleus found in the cell.
Contractile Vacuole: The contractile vacuole removes excess water to the outside
from time to time (osmoregulation).
Food Vacuole: Microscopic organisms are digested and then exits through a structure
called a food vacuole.
Digestive Vacuole: This is a cavity responsible for digestion in the amoeba.
Pseudopodium: Pseudopodium means ‘false foot’. The amoeba move by stretching
its cytoplasm into finger like extensions called pseudopodia
15.
16. Nutrition in amoeba is holozoic.
Solid food particles are ingested which are then acted upon by enzymes
and digested.
Lysosomes attached to food vacuole
Lysosomes secrete enzymes like proteases, amylases and lipases
in food vacuole
Food vacuole decreases in size due to water loss
It increases acidity and PH becomes 5.6 and Then 7.3
Fine canals produced from digestive vacuole
Absorption of food takes place by micropinocytosis
Food is circulated throughout the cytoplasm by cyclosis.
19. Multicellular
Diploblastic
Belongs to phylum Cnidarians'
Macrophagus feeder
Aquatic animal
At the anterior end mouth surrounded with tentacles which are used to
capture the pray
In tentacles special cells Nematocysts are present
Nematocysts contains poison which paralyze the pray.
21. The mouth of hydra opens into a cavity called gastrocoel or
enteron.
The endoderm contains two types of cells, glandular and
flagellated.
Glandular cells secrete proteolytic enzymes , which are helpful in
digestion
The flagellated cells and contraction of body wall also help in
digestion
Hydra cannot digest starch.
The digestion is extracellular as well as intracellular
22.
23. Flatworm
Belongs to phylum Platyhelminthes
Carnivores
Tube like alimentary canal is present
It has three parts: mouth, pharynx and intestine
When it takes food from outside, the pharynx comes out from the
mouth
Internally the pharynx opens into the intestine, which divides into
three branches
25. The branching system is formed for digestion, absorption and
distribution of food
This system is called Gastro-Vascular system
The food is taken in through the mouth which comes into the
pharynx and then intestine
The enzyme act upon the food in the intestine
The digested food is absorbed by the branches of intestine, which is
distributed throughout the body by diffusion
Digestion is both intracellular and extracellular
28. conclusion
The process of intake of food and its conversion into
living protoplasm in cells
Most of the lower animal that possess hetrotrophic
nutrition
Amoeba, Hydra ,and Planaria each one possess
different mode of nutrition
29. Quiz paper
Q1: The nutrition which is obtained by digesting organic compounds is called as
Holozoic
Heterotrophic
Autographs
Saprotrophs
Q2: There are five steps of holozoic nutrition: Ingestion, digestion, absorption ,
assimilation and egestion.
True
False
Q3: The digestion in hydra is _______________ as well as ___
Q4: In tentacles special cells called _______________ are present
Q5: The process of ingestion takes place by _______________ in amoeba.
