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Name ________________ Nº___

Surname __________________________

NATURAL SCIENCE

UNIT 1. CELLS & LIVING THINGS

Exam Date: __________________

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UNIT 1. CELLS & LIVING THINGS In this unit we are going to learn about:

1. Cells - What are cells? - Vital functions: Nutrition, reproduction and interaction - Shape and size - Cell structure

• Parts of a cell • Animal and plant cells

2. The organization of multicellular organisms

- Living things: unicellular and multicellular - Multicellular organisms: levels of organization

Science Investigators

Do you have any other questions? Write them down and let’s find the answer

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Do you think animal and plant cells are different?

Do you know what is the smallest living thing?

Which is the largest organ in the

human body?

Do you think there can be living things

with just one cell?

What do a cell and a whale can have in common? What makes plants green?

Is a seed a living thing?

The brain controls everything that we do. Do you think cells have brains?

Are cells of an elephant bigger than the cells in a mouse?

Why do we say that some things are microscopic?

Are you a living thing? Why?

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1. CELLS WHAT ARE CELLS? • All living things are made up of very small units called cells. Cells are the basic units

of life.

• Cells are the smallest living units that make up a living thing. They are so small that

we need a microscope to see them, that is why we say they are microscopic.

• Cells are living things so they carry out the three basic life processes:

- Nutrition: cells obtain nutrients and energy from food.

- Reproduction: Cells can divide and produce new cells that are identical to

themselves. - Interaction: Cells react to what they perceive around them.

SHAPE AND SIZE • Most cells are very small and can only be seen through a microscope. However, they

can differ in:

- size. for example, brain cells, known as neurons, are much bigger than red

blood cells.

- shape: they can be round, elongated, flat, star-shaped, etc.

• Cells can specialize to perform a particular function, for example brain cells, blood

cells, muscle cells, etc.

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STRUCTURE • All animal and plant cells have got three main parts: the membrane, the cytoplasm

and the nucleus.

- The membrane. This is the covering around the cell. It surrounds and protects

the cell. It also controls what enters and leaves the cell, that is, the exchange of

substances.

- The cytoplasm. It is a thick, clear liquid composed mainly of water. This jelly-

like substance is located between the nucleus and the membrane and contains

the organelles that perform different functions of the cell.

- The nucleus. It controls all the functions of the cell, that is, the nucleus

controls everything that happens inside the cell.

• In plant cells, there is also a cell wall and chloroplasts:

- Cell wall: It is a thick, rigid structure that protects the cell and gives it its shape.

It is made of cellulose. We can use cellulose from certain plants, such as

eucalyptus, to make paper.

- Chloroplasts: These special organelles contain chlorophyll. They absorb

sunlight which plants need to make their food (photosynthesis).

* Plant cells are usually bigger than animal cells and have a regular shape. Animal cells

can be many different shapes but plant cells are usually rectangular or polygonal.

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2. THE ORGANIZATION OF MULTICELLULAR ORGANISMS

LIVING THINGS: UNICELLULAR AND MULTICELLULAR As we said before, all living things are made up cells. Depending on the number of cells,

living things can be:

- Unicellular: Living things made up of a single cell (e.g. bacteria). In a unicellular

organism, there is only one cell that performs all the three vital functions.

- Multicellular: Living things made up of many cells (e.g. animals and plants). In a

multicellular organism, different cells carry out different functions.

MULTICELLULAR ORGANISMS: LEVELS OF ORGANIZATION Multicellular organisms are made up of many different types of cells. These cells work

together at different levels called levels of organization.

Ø Specialized cells Cells specialize to perform a particular (specific) function.

e.g. muscle cells, neurons, red blood cells.

Ø Tissues Cells of the same type join together to form tissue and are organized according to

their function.

e.g. muscle tissue, epithelial tissue.

Ø Organs Multiple tissues group together to form organs. Tissues in organs work together to

perform a common function.

e.g. Muscle tissue makes up muscles, epithelial tissue makes up the surface of the

skin.

Ø Systems Organs are organized to form systems. Organs in systems work together to perform

a common function.

e.g. Nervous system, respiratory system.

Ø Organisms All the different systems work together to form and organism, a living thing.

e.g. a cat, a mosquito, a baby.

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UNIT VOCABULARY 1. _______________ - _______________

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In this unit I have learned:

1.- _________________________________________________________

2.- _________________________________________________________

3.- _________________________________________________________

I would like to learn more about:

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REFERENCES - Science 5 Primary, sm, 2009.

- Science The world around us 5 Primary Education. Anaya English, 2013.

- Science The world around us 6 Primary Education. Anaya English, 2013.

- Natural and Social Science Primary 5 Pupil’s book Macmillan, 2012.

- Natural Science 5 Primary Student’s book. edebé, 2015.

- Natural Science 5 Primary Activity Book. edebé, 2015 .

- Natural Science. Primary 5 Anaya English- ANAYA, 2014.

- Natural Science. Primary 6 Anaya English- ANAYA, 2015.

- Natural Science. Primary 5 (Activity Book) Anaya English- ANAYA, 2014.

- Social and Natural Sciences 5 Look and Think Oxford Education, 2010.

- Natural Science 5 (Comunidad de Madrid) Vicens Vivens, 2015.

- Natural Science Our World (Comunidad de Madrid) Richmond, 2015.

- Natural Science Primary 5 (Comunidad de Madrid) ByME Macmillan & Edelvives, 2015.

- Top Science 5 Primary. Ed Santillana/ Richmond, 2011.

- Top Science 6 Primary. Ed Santillana/ Richmond, 2011.

- Science “My World” Primary 6, Edelvives, 2013.

WEBS

• https://www.ducksters.com/science/the_cell.php

• https://kidsbiology.com/biology-basics/what-is-a-cell/

• http://www.biology4kids.com/files/cell_main.html

• https://kids.britannica.com/kids/article/cell/352933

• https://online.kidsdiscover.com/unit/cells?ReturnUrl=/unit/cells

• https://kids.kiddle.co/Multicellular_organism

• https://kidsbiology.com/biology-basics/structure-of-living-things/

• http://www.kidsdiscover.com/spotlight/kids-cells/?wpss-routing=results

• https://biologywise.com/levels-of-organization-of-living-things

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