Nutrition involves the processes by which living things obtain energy and matter from food. There are two main types of nutrition: autotrophs like plants produce their own food, while heterotrophs obtain food from other organisms. Nutrition requires digestion to break down food, respiration to release energy, circulation to transport nutrients, and excretion to remove waste. Plants carry out similar processes to obtain inorganic nutrients from the soil and produce organic matter through photosynthesis.

1. NUTRITION

2. WHAT IS NUTRITION?
 It is a set of processes through which living
things take food, and covert it into their own
matter and energy.
 According to the type of nutrition, living things
are classified as:
◦ Autotrophs.
◦ Heterotrophs.

3. ◦ AUTOTROPHS: make their own organic matter
from inorganic matter using a source of
energy:
 Photoautotrophs: use energy from the
sun to produce food (plants).
 Chemoautotrophs: use energy from
chemical reactions to produce food
(bacteria).

4. ◦ HETEROTROPHS: feed on organic matter
produced by other living things. They
transform this matter to obtain nutrients and
energy.
◦ Herbivores → They feed on plants
◦ Carnivores → They feed on animals
◦ Omnivores → They feed on plants and animals

5. Nutrition involves four processes:
1.Digestive Process.
2.Respiration.
3.Circulation: substances transport.
4.Excretion.

6. What is the digestive process?
 Digestion includes all the processes which break
down food into simple substances which are used
for energy, growth and cell repair.
 It has four stages in animals:
◦ Ingestion
◦ Digestion
◦ Absorption
◦ Egestion

7. 1. Ingestion → food comes into the body through
the mouth.
2. Digestion → is the transformation of food into
nutrients. There are two types:
◦ Intracellular: It occurs in individual cells.
◦ Extracellular: It occurs in the digestive tube.
The transformation of food is both mechanical
and chemical:
 Mechanical: food is broken itno smaller pieces.
 Chemical: food is transformed chemically
through the action of enzymes.

9. 3. Absorption → is the passage of nutrients
from the digestive system into the blood. The
blood carries the nutrients to the cells.
4. Egestion → is the elimination of undigested
and waste products from the digestive system.
These products are transformed into faeces
and expelled from the organism.

10. What digestive systems are there?
 There are two main types:
◦ Gastric cavity → in animals with intracellular
digestion. Ex. Sponges.

11. ◦ Digestive tube → It begins in the mouth,
where food enters, and ends in the anus,
where food wastes are expelled. It is found in
animals with extracellular digestion.

12. How do animals breathe?
 Animals breath by inhaling oxygen from the
outside, and then exhaling carbon dioxide.
This gas exchange takes place in the
Respiratory System.
There are four types of respiration in animals:
1. Cutaneous Respiration
Gas exchange occurs through
the skin. Ex. Amphibians.

14. Gills and
Operculum Trachaea

15. 4. Pulmonary respiration:
Gas exchange occurs in the lungs.
It takes place in two movements:
- Inhalation: air comes in the lungs.
- Exhalation: air comes out the lungs.
This occurs in birds, reptils, mammals and some
amphibians.
http://www.educaplus.org/play-59-Centro-respiratorio.html

16. Circulatory Systems
The circulatory system has two functions:
◦ It carries nutrients and oxygen to the cells.
◦ It removes carbon dioxide and waste products from
the metabolism.

17. The circulatory system consists on:
◦ Blood: fluid made up of proteins, water and
cells.
◦ Blood Vessels: ducts which carry blood.
Arteries, Veins and Capilars.
◦ Heart: an organ like a pump which makes
blood circulate.
http://www.edumedia-sciences.com/
es/a387-circulacion-sanguinea

18. Types of circulatory system:
- Open: The circulating fluid flows through the
body cavity, and bathes the internal orgams
directly ( molluscs and arthropods)
- Closed: The blood always circulates inside
blood vessels. It can be Simple or Double.

19.  Ina Simple circulatory system, the blood only
passes through the heart once (fish).

20.  In a Double circulatory system, the blood
passes through the heart twice (other
vertebrates).

21. Excretion
 Itis the process of collecting waste products,
such as carbon dioxide, ammoniac and urea,
and expelling them outside the body.
 It is carried out by the Malpighian Tubules in
insects, and the Excretory System in
vertebrates

23. PLANTS NUTRITION

24.  Plantsare autotrophs, they produce organic
matter from inorganic matter.
 Processes of plant nutrition:
1. Absorption → is the movement of water and
mineral salts (Raw Sap) from the ground to
the interior of the roots.

25. 2. Transport of raw sap → it travels up the
steam to the leaves of the plant through Xylem
Vessels.

26. 3. Gas exchange → occurs in the leaf stomata.
Carbon dioxide enters the plant and oxygen
leaves. In this process, water evaporates
(transpiration).

27. 4. Photosynthesis → it takes place in the
chloroplasts of the green parts of the plant.
Chlorophyll absorbs sunlight to produce energy,
which transforms raw sap and carbon dioxide
into elaborated sap (glucose).
Water + Mineral Salts + CO2 + Sunlight  O2 + Glucose

29. 5. Transport of elaborated sap → goes from
the green parts of the plants to all parts, through
the Phloem Vessels.