Page 3 - ตัวอย่าง Science Solution 1

1.1 Unicellular and Multicellular Organisms

Living organisms in this world are plants, animals and protists, both microscopic and macroscopic in
sizes. The organisms may consist of only single cell or millions of cells. Classifying these organisms into groups
using different criteria will result in having many types. If numbers of cells are used to classify these organisms,
there will be different two groups, the unicellular and multicellular organisms as shown in the pictures below.

1. Unicellular Organisms which are
organisms with only single cell that may contain a
nucleus or none. Any substances in the nucleus spread
all over the cell. The interior structure of a cell is simple.
These organisms can be generally found living freely
Amoeba Paramecium both in water and land habitats.
Unicellular organisms live in a similar manner
to multicellular organisms. They are able to perform
different activities such as eating, digesting, moving and
reproducing in general.

Examples of unicellular organisms are Amoeba,

Paramecium, Chlorella, and Diatoms.
Chlorella Diatoms

Figure 1.1 Examples of Unicellular Organisms

2. Multicellular Organisms are organisms with
more than 1 cell, which are seaweeds, mushrooms,
fungi, plants and animals in general. Hydra

Planarian

Examples of multicellular
organisms are hydras,
planarians, earthworms
and coat buttons.

Coat buttons

Earthworm
Figure 1.2 Examples of Multicellular Organisms

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