UNIT 2. THE NUTRITION FUNCTION

WHAT TO LEARN To study nutrition: processes and their

different types. To learn about nutrition in cells and plants. To understand nutrition in animals:

Feeding and digestion. Breathing Circulation Excretion

STOP AND THINK What is the scientific name for “obtaining

nutrients”? What is the scientific name for “obtaining

oxygen”? What is the scientific name for “eliminating

waste substances”?

1. WHAT IS NUTRITION?

THE PROCESSES OF NUTRITION

Obtaining nutrients Respiration Distributing

substancesExcretion

TYPES OF NUTRITION

AUTOTROPHIC NUTRITION

HETEROTROPHIC NUTRITION

Producing organic nutrients from

inorganic substances.

Obtaining organic nutrients by feeding

on other living things.

Ex: Plants Ex: Animals

RESPIRATION

Taking oxygen from the

environment.

Oxygen is used to obtain energy.

Respiration produce carbon

dioxide and water.

SUBSTANCE DISTRIBUTION

Nutrients are distributed to all parts

of the organism.

EXCRETION

Elimination of waste products.

NUTRITION IN CELLS

UNICELLULAR ORGANISMS

One cell carries out the four processes.

MULTICELLULAR ORGANISMS

They have organs and systems specialised to

perform the four processes.

PLANT NUTRITION1. OBTAINING NUTRIENTS

The absorption of water and mineral salts

Carbon dioxide absorption Photosynthesis

Plants absorb water and

minerals (xylem sap) through

root hair.

CO2 enters through little

pores (stomata) in the leaves .

In the chloroplast, water , mineral salts

and CO2 are transformed to

organic nutrients (phloem sap). Thanks to the

chlorophyl and sunlight.

PHOTOSYNTHESIS

PLANT NUTRITION

2. RESPIRATION

1. The plant absorbs oxygen.2. The oxygen is used in the

mitochondria to produce energy.3. Respiration produces water and

CO2

PLANT NUTRITION

3.SUBSTANCES DISTRIBUTION

Substances are distributesd through vessels along the stem, branches and leaf

veins.

XYLEM SAP: FROM THE ROOTS TO THE

GREEN PARTS

PHLOEM SAP: FROM THE GREEN PARTS TO

EVERYWHERE

4. ELIMINATING WASTE MATTER

PLANT NUTRITION

O2 , CO2 and water are eliminated

through stomata.

Waste matter is stored in old

leaves.

Sticky substances (latex and resin) help

disinfect and protect.

ANIMAL NUTRITIONNUTRITION PROCESS

FEEDING DIGESTION

Two parts

It consists in ingesting

food.

WITH A DIGESTIVE SYSTEM

GASTROVASCULAR CAVITIES: Structures with an opening used for ingestion food

and elimination of indigestible matter. Ex: Cnidarias and pltyhelminthes.

DIGESTIVE TRACTS: Long tubes. Two openings: one for food (mouth) and

one for indigestible matter (anus). Examples:

Annelids: they don’t have digestive glands. Molluscs, arthropods and vertebrates have digestive

glands.

THE DIGESTIVE PROCESS 1. Food is crushed by mechanical and chemical

processes. 2. Nutrients are absorbed. 3. The rest of the food is eliminated-

BREATHING IN:

WATER(External surfaces)

AIR(Internal surfaces)

THROUGH BODY SURFACE. Ex: Cnidaria, Earthworms…

THROUGH TRACHEAE.Ex: Insects

THROUGH GILLS.Ex: Fish, molluscs…

THROUGH LUNGS.Ex: Vertebrates.

CIRCULATION: TRANSPORTATION OF SUBSTANCES SIMPLE ANIMALS: They interchange

substances directly with the environment. Ex: Sponges and Cnidaria.

COMPLEX ANIMALS: They have a circulatory system formed by:

A circulating liquid. Ex: blood.Vessels and a pump (heart)

Two types of circulatory system:Open circulatory system. Ex: Arthropods.Closed circulatory system. Ex: Fish, mammals.

EXCRETION: ELIMINATING WASTE SUBSTANCES SIMPLE ANIMALS:

They eliminate waste substances through their body surface.

Ex: Cnidaria and sponges. COMPLEX ANIMALS: They eliminate

substances through: Respiratory organs. CO2 is expelled. Excretory organs: They collect the waste

matter. Ex: kidneys.

ACTIVITIES1. The following sentences are true or false?a) Organisms take organic nutrients from the

environment.b) Autotrophic nutrition consists of obtaining

organic nutrients by feeding on other living things.

c) Organisms carry out respiration by taking CO2 from the environment.

d) Living things distribute nutrients to all parts of their organism.

2. Complete the following sentence using these words: Organic-energy-nutrients- inorganic-repair

Living things must get ________ that can be _______ or _________ substances which can be used to ______ the cells and to obtain_______.

3. Explain the difference between autotrophic nutrition and heterotrophic nutrition.

4. Write these parts in English.

5. What’s the difference between a circulatory system and the circulation of a sponge?

6. These structures are called:a) Pores found on the underside of leaves.

b) Organs in fish used to get O2 in water.c) Long tubes with two openings to perform the digestion.d) Internal surfaces with wet walls to get oxygen.

7. Match:

8. Explain what type of digestive system have:a) A jellyfishb) A reptil

9. Explain what type of circulatory system have:a) A fishb) A sponge

1.Thracheas 2.Gastrovascular cavity3.Kidneys

a. Obtaining nutrientsb. Excretionc. Breathing

1. Cnidaria2. Vertebrates3. Insects

10. Complete the following sentences with the correct word: leaf, water, veins, phloem sap, carbohydrates, photosynthesis.

a) Plants release oxygen from___________, CO2 from respiration and excess____________ (as vapour) through the_____________.

b) The transportation of____________ in the plant takes place through the vessels which run along the_______, the branches____________ of the leaves.

c) The____________ (organic nutrients) which are made in photosynthesis are mixed with water in the__________ and form the _____________ ______________.

11. Complete the table with a tick. ()ANIMAL WITHOUT

DIGESTIVE SYSTEM

WITH A GASTROVASCULAR CAVITY

WITH DIGESTIVE TRACT

Anchovy

Planarian

Sponge

Rabbit

Grasshopper

Jellyfish

Elephant

Frog

12. Write down the type of breathing:a) Fish b) Earthwormc) Mosquito d) Parrot