1. 6 NUTRITION6 NUTRITION

2. What is Nutrition?What is Nutrition?
The entire process by which organism
obtain energy from food for growth,
maintenance and repair of damaged
tissues
Nutrient – the substances that are
required for the nourishment of an
organism

3. 6.1 Type of Nutrition6.1 Type of Nutrition
Two main types:
1. Autotrophic
2. Heterotrophic

4. 1. Autotrophic1. Autotrophic
 A process in which organisms synthesise
organic substances from inorganic
substances
 Autotroph = Auto – self, trophos – feed
(organism which can make their own food)
 The source of energy for synthesising food
can be either light energy or chemical
energy.

5. The synthesis of food using light
energy – photosynthesis (photo –
light)
Photoautotroph – organisms which
produce organic molecules from
carbon dioxide and water using
sunlight as a source of energy
Example: green plants

6. The synthesis of food using chemical
energy – chemosynthesis (chemo –
chemical)
Chemoautotroph – organisms which
synthesise organic compound by
oxidising inorganic compound
(hydrogen sulphide and ammonia)
Example: certain bacteria
(Nitrosomonas sp. and Nitrobacter sp.)

7. 2. Heterotrophic2. Heterotrophic
A type of nutrition in which organism
obtain energy through the intake and
digestion of organic substances.
Heterotroph =Hetero – other,
trophos – feed (organism that cannot
synthesis their own nutrients but
obtain the nutrients from other
organisms)

8. They may practice
a) Holozioc nutrition,
b) Saprophytism
c) Parasitism

9. - holo –like, zoon – animal
- The organism feeds by ingesting
solid organic matter which is
subsequently digested and
absorbed into their bodies
- Examples: humans, herbivores,
carnivores and some carnivorous
pitcher plants and Venus fly-traps
a) Holozoic nutritiona) Holozoic nutrition

10. - The organism called saprophytes
- Feed on dead and decaying
organic matter
- Digest their food externally
before absorbing the nutrients
into their bodies
- Examples: bacteria, fungi
b) Saprophytismb) Saprophytism

11. - The organism called parasite
- Obtain nutrient from living on
(ectoparasites) or in (endoparasites)
the body of another living organism
(host)
- They absorbs readily digested food
from its host
- Examples: fleas (ectoparasites), lice,
worms (endoparasites), Rafflesia
plant
c) Parasitismc) Parasitism

12. Test YourselfTest Yourself
1. Differentiate between autotrophic and
heterotrophic nutrition.
A: Autotrophic nutrition – A process in
which organisms synthesise organic
substances from inorganic substances
Heterotrophic nutrition - A type of
nutrition in which organism obtain
energy through the intake and
digestion of organic substances.

13. 2. Name two types of autotrophic
nutrition.
A: Photosynthesis and chemosynthesis
Test YourselfTest Yourself

14. 3. Name three types of heterotrophic
nutrition.
A: Holozoic nutrition, saprophytism and
parasitism
Test YourselfTest Yourself

15. 4. Name the nutritional habits of the
following organisms;
a) Pitcher plants
A: holozoic nutrition
b) Green algae
A: photosynthesis
d) Tapeworm
A: parasitism
Test YourselfTest Yourself