NATURAL SCIENCE 5º. UNIT 1: LIVING THINGS

 

UNIT 1 : LIVING THINGS

 

1.1.      Characteristics of living things.

1.2.      How are living things classified?

 

1.1 Characteristics of living things

 

Ø Cell structure

A cell is the smallest living unit. There are two types: animal cell and plant cell.

·        Animal cell: Components: nucleus, cell membrane, cytoplasm and vacuole.

 

 

·        Plant  cell: Components: nucleus, cell membrane, cytoplasm, cell wall, chloroplast and vacuole.

         We can find two types of organisms:

-         Unicelullar organisms: They have just one cell.

-         Multicellular organisms: They are made up of many cells.

 

Ø Vital functions

The most important ones are: nutrition, interaction and reproduction.

·        Nutrition: All living things obtain nutrients from their environment to have energy. There are three types of nutrition:

 

-         Plants: They obtein nutrients from the photosynthesis.

-         Animals: They eat other living things.

-         Decomposers: They feed on the remains of dead plants and animals.

 

·        Interaction: Through the interaction we need a stimulus and the reaction is a response.

 

·        Reproduction: We can find two types: asexual and sexual reproduction.

 

-         Asexual reproduction.- The organism reproduce itself. Example: bacteria.

-         Sexual reproduction: The organism need a male and female to reproduce. Example: human beings.

 

1.2  How are living things classified?

 

Living things are classified in groups called kingdoms. There are five kingdoms in our nature: plant kingdom, protist kingdom, monera kingdom, animal kingdom and fungus kingdom.

 

 

 

Ø Plant kingdom. Characteristics:

 

-         They are multicellular.

-         They make their food through the photosynthesis. Plants absorb carbon dioxide and expel oxygen through the photosynthesis. Example: trees.

 

Ø Protist kingdom. Characteristics:

 

-         Most of them are unicellular but there are multicellular as well.

-         They live in water.

-         Examples: amoeba ( unicellular) and algae ( both of them).

 

Ø Monera kingdom. Characteristics:

 

-         All the organisms are unicellular.

-         They live in the air, in water and on the land.

 

Ø Animal kingdom. Characteristics:

 

-         Animals are multicellular.

-         They feed on the other living things.

 

Ø Fungus kingdom. Characteristics:

 

-         They can be unicellular and multicellular.

-         They feed on the remains of dead plants and animals. They are called decomposers.