Control Ciencies Naturals

1. Explica per què es considera la cèl·lula la unitat fonamental dels éssers vius.

Per què en la que estan formatis tots el teixits del nostre cos.

2. Escriu el nom dels orgànuls i de les parts de les cèl·lules eucariotes que es corresponen amb les funcions proposades

Digestió---------------------------------> Lysosomes

Locomoció------------------------------> Vesicles

Magatzem de nutrients---------------> Golgi Apparatus, Vacuoles

Fotosíntesi------------------------------> Chloroplast

Síntesi de proteïnes--------------------> Ribosomes

Suport de la cèl·lula-------------------> Cilia and Flagella

3. Fes una llista dels aparells i sistemes que formen el cos humà. Quines són els tres funcions vitals dels éssers vius? Quins aparells i sistemes participen en cadascuna d'elles. ( contesta al full apart.)

4. Relaciona els termes següents (escriu a la dreta de la segona columna què són):

Bacterium

Cell Heart

Tissue Onion Epidermis

Organ Red blood cell

Apparatus (organ system) A cat

Organism Nervous system

A potato plant

5. Indica si són veritables (V) o falses (F) les afirmacions següents.

The bigger animals have bigger cells than the smaller animals.

There are no organisms made up of only one cell.

Bacteria have no nucleus

The shape of cells is very varied.

Vegetables are made up of procaryotic cells.

All eucaryotic cells have cell organelles.

Procaryotic cells have got a cytoplasm.

We usually measure the length of a cell in centimetres.

6. Explain the most important differences between the two main kinds of cells:

	Procaryotic cells	Eucaryotic cells
Size
Nucleus
Organelles

Write down any other additional difference between them that it is worth mentioning.

8. Com es classifiquen els teixits del cos humà? Fes-ne un esquema o explica els quatre tipus bàsics de teixits i les seves diferents classes.

9. Label the illustration:

Cell: Activities.

- Activity 4:

· Search what procaryotic and eucaryotic cells have in common.

- Both have DNA as their genetic material (it’s DNA that tells cells what kind of cells they should be).

- Both are covered by a cell membrane.

- Both contain RNA.

- Both are made from the same basic chemicals: carbohydrates, proteins, nucleic acid, minerals, fats and vitamins.

- Both have ribosomes (the structures on which proteins are made).

- Both regulate the flow of the nutrients and wastes that enter and leave them.

- Both have similar basic metabolism (life processes) like photosynthesis and reproduction.

- Both require a supply of energy.

- Both are highly regulated by elaborate sensing systems ("chemical noses”) that make them aware of the reactions within them and the environment around them.

· What are the differences?

- Structural Differences

Eukaryotic cells contain two important things that prokaryotic cells do not: a nucleus and organelles (little organs) with membranes around them.

- DNA arrangement

Although both eukaryotic and prokaryotic cells contain DNA, the DNA in eukaryotic cells is held within the nucleus. In prokaryotic cells, the DNA floats freely around in a unorganized manner.

- Size

Eukaryotic cells are, on average, ten times larger than prokaryotic cells.

- Cell wall diferents

Prokaryotic cells have a cell wall composed of peptidoglycan (amino acid and sugar). Some eukaryotic cells also have cells walls, but none that are made of peptidoglycan.

- Age differences

- 4.6 billion years ago the Earth was formed
- 3.5 billion years ago the first life arose: prokaryotic bacteria
- 1.5 billion years ago eukaryotic cells arose
- 0.5 billion years ago the Cambrian explosion – multi-celled eukaryotes arose
- 3 million years ago our earliest ancestors, the hominids, appeared