Growth, Development, & Levels of Organization Notes

The 6 characteristics all organisms share:

1. Have at least 1 cell

2. Can grow & develop

3. Can reproduce

4. Have genetic material

5. Have a metabolism

6. Can adapt & evolve

Growth & Development

Growth the process where living things increase in size

Development the process where living things get new body parts

and/or abilities

As an organism goes through its life, both of these processes happen togetherNot all organisms grow to the same size or develop the

same parts, though

Development

All organisms start their lives as a single cell

Unicellular organisms stay single-celled

In multicellular organisms, that cell divides into 2 cells

Those 2 cells divide to become 4 cellsThose 4 cells divide to become 8 cellsThose 8 cells divide to become 16 cellsThose 16 cells divide to become 32

cells, etc…

This means that each of the several trillion cells in your body are the great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, (you get the idea…) grandchild of the first cell in your body.

Not all the cells in your body look or act the same, but they all came from the same place

Specialized cells (differentiated cells) – cells that have developed a specific shape, specific organelles, and a specific job

Stem cells - cells that have the ability to turn into many different types of specialized cellsThe fertilized egg is the stem cell responsible for all the

specialized cells in an adult organism’s bodyYou still have stem cells as an adult

Cell Specialization

Pre-Birth Development Development of most organisms

begins very shortly after fertilization Fertilization is when the sex cells from

different organisms combine

Development continues during gestation, incubation, or germination Gestation is the time between

fertilization and birth in mammals (developing inside mother)

Incubation is the time between fertilization and hatching for many animals (developing inside egg)

Germination is the time between fertilization and sprouting in many plants, bacteria, and fungi (development inside a seed or spore)

Types of Development

After birth, hatching, or sprouting, organisms can take different paths to adulthood.

Gradual development – type of development where the organism looks similar to the adult version at each stage

Metamorphosis – type of development where the organism looks very different from the adult version at each stage

Gradual development

Most organisms develop this way (including humans)

Metamorphosis

Most insects develop this way

Frogs are an example of a vertebrate that develops this way

The 6 Levels of Organization

Having specialized cells means that the body of the organism must be really well organized so jobs don’t get repeated or missed

Organism Organ system Organ Tissue Cell Organelle

OrganismA living thingMade of a collection of different organ systems that work

together

Organ systemA collection of different organs that work together

OrganA collection of different tissues that work together

TissueA collection of cells of the same type that work together

CellA collection of molecules that meet the characteristics of lifeMade of molecules and organelles that work together

OrganelleA tiny structure inside a cell that has a specific jobMade of a collection of different molecules that work together