+

Its Alive – or is it?

The Characteristics of Life

+I can…

Describe the biological criteria that need to be met in order for an organism to be considered alive

+6 Characteristics of Life

In order for ANY organism, no matter how large or small, to be considered alive, it must exhibit the following 5 characteristics:

1. Organization

2. Ability to acquire materials and energy

3. Ability to maintain homeostasis

4. Ability to respond

5. Ability to reproduce and grow

6. Acquire adaptations

+Organization within a living organism…

Organization of living things begins with atoms, which make up basic building blocks called elements and molecules

The cell is made up of molecules and is the basic structural and functional unit of all living things

Different cells combine to make up tissues

Tissues combine to make up an organ

Specific organs work together as an organ system

Multicellular organisms contain organ systems

Each level of organization is more complex that the level preceding

+Working with what we have learned…

Make flow chart of the levels of organization – within an organism

At each level, give at least 2 examples

+Organization between living organisms…

A species is the same type of organism

A population is group of the same species in a particular area

Interacting populations in a particular area is a community

A community PLUS its physical (non-living) environment is an ecosystem

The biosphere is comprised of regions of the Earth’s crust, waters and atmosphere inhabited by organisms

+Working with what we have learned…

Using our classroom as our “particular area”, give examples for each level of organization found between organisms

+Acquire Materials and Energy

Maintaining organization and conducting life-sustaining processes require an outside source of energy The ultimate source of energy for nearly all live on earth is

the sum Plants and certain other organisms convert solar energy

into chemical energy by the process of photosynthesis

Metabolism is all the chemical reactions that occur in the cell

+Ability to maintain homeostasis…

All organisms must maintain a state of biological balance, or homeostasis Temperature, moisture level, pH level, etc.. Must be

maintained within the tolerance range of the organism

Organisms have intricate feedback and control mechanisms to maintain homeostatic balance

+Ability to Respond…

Living things interact with the environment and with other living things and need to respond accordingly

Response often results in movement of the organism A plant bending toward the sun to capture solar energy or a

turtle withdrawing into its shell for safety

Responses help ensure survival of the organism and allow the organism to carry out biological activities

The collective responses of an organism constitute the behavior of the organism

+Ability to reproduce and grow…

Reproduction is the ability of every type of organism to give rise to another organism like itself Bacteria, protozoans, and other unicellular organisms

simply split in two (binary fission) – asexual reproduction Multicellular organism often unite sperm and egg, each

from a different individual, resulting in an immature individual which develops into the adult – sexual reproduction

The instructions for an organism’s organization and development are encoded in genes Genes are comprised of long molecules of DNA

(Deoxyribonucleic acid) DNA is the genetic code for all living things

+Acquire to Adaptations…

Adaptations are modifications that make organisms suited to their way of life

Occur over a long period of time

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