5.1. LIVING THINGS

UNIT 1: LIVING THINGS

1. INTRODUCTION

Life on Earth first appeared approximately 3.8 billion years ago. The first living things were single cells similar to bacteria. It was only much later, around 570 million years ago, when more complex organisms started to appear. Since then, life forms can be found almost everywhere on Earth, but what about in the rest of the Universe? Do you know if there is life on other planets?

ACTIVITY:

a)    Do you think these things are living or non-living? Complete the table.

-         mould                          - moss                                              - water

-         stone                           - apple tree                                       - spider

Living things	Non-living things

     b)  What differences can you find between the two columns?

     2.     THE CHARACTERISTICS OF LIVING THINGS

     A)    VITAL FUNCTIONS

In spite of their differences, all living things perform three vital functions in order to live and grow: NUTRITION, REPRODUCTION AND INTERACTION.

a)      NUTRITION
Living things need energy in order to carry out their life functions. Energy comes from nutrients (food). Nutrients help them to grow and function properly.
Animals	Animals do not make their own food. Some eat meat (carnivores), some eat plants (herbivores) and some eat meat and plants (omnivores).
Plants	Plants use sunlight, water, carbon dioxide and minerals to make their own food (photosynthesis).

b)      REPRODUCTION
Living things reproduce. Reproduction means they can make other living things.
Animals	Some animals are born live (viviparous) and others are born from eggs (oviparous).
Plants	Most plants reproduce by seeds, spores or a piece of the same plant.

c)       INTERACTION
Living things interact with the world around them. Moving, touching and communicating are examples of interaction.
Animals	Animals can move, communicate, hunt and react to the world around them. Some animals live in group and some animals live alone.
Plants	Plants also react to the environment. They grow towards the light and their roots grow towards water. Some plants open and close, and some plants can climb.

3. VITAL FUNCTIONS AND BODY SYSTEMS

* Complete this table in class.

System	Function	Main Organs	Vital Function	Picture

4. THE CELL

All living things are made up of tiny units called cells and perform the three vital functions: nutrition, interaction and reproduction. A cell is the smallest unit of life.

CELL STRUCTURE

Plant and animal cells have the following parts: 

                              Animal cell                                                                    Plant cell

Real cells under a microscope

 

5. Multicellular and unicellular organisms

6. Multicellular organisms

Multicellular organisms are living things that are composed of two or more cells. For example humans.
In multicellular organisms, cells are grouped to form different levels of organization. The end result is an organism.

    *Complete the table:

REVIEW

1. Copy and complete this mind map in your notebook by adding the main organs of the different body systems.