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)
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
