Page 49 - Science Course 1 (Book 1)

Mo2-L2a: What are the Characteristics of Life?

A cell is every organism’s smallest unit of life. Changes that occur in an organism during its lifetime
are called development.
Unicellular organisms are organisms made of In multicellular organisms, development happens as
only one cell. cells become specialized into different cell types.

Some organisms have
dramatic developmental
changes, such as a tadpole
Living things that are made of two or more cells
are called multicellular organisms. becoming a frog.

Reproduction
Reproduction is the process by which one organism
makes one or more new organisms.

Unicellular Organism Some organisms can
reproduce by dividing
and becoming two new
organisms.

Some organisms must
have a mate to
reproduce, but others
can reproduce
Such as amoeba, Bacteria and Yeast without a mate.

Multicellular Organisms
Responses to Stimuli
All living things respond to changes in the
environment called stimuli.
There are two types of stimuli:
2 TYPES OF STIMULI

Internal Stimuli External Stimuli
Mucor

are changes within an are changes in an
organism. organism’s environment.

Changes outside our
Changes inside our body body eg. Light intensity,
eg. Blood osmotic
pressure & sugar level temperature, pressure &
sound

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