What Is Life? Chapter 1

Characteristics of Living ThingsLife Comes From Life

Needs of Living ThingsLiving, Non-living & Dead

Characteristics of Living Things: All living things… Are made of

cells. Have the Ch

emicals of Life.

Use Energy. Are able to g

row and develop.

Will respond to a stimulus.

Are able to reproduce.

Cellular Organization

Cells: The basic unit of structure and function in an organism.

Organism: A living thing that shares all of the characteristics of living things.

Unicellular: single celled organisms (bacteria)

Multicellular: Many celled organisms

Chemicals of Life

Water (most abundant) Carbohydrates (energy

source) Proteins & Lipids

(building materials) Nucleic Acids (genetic

material)

Carbohydrates:

The main source of energy for living things.

Sugar and starch Fruits

Proteins:

Eggs, meat, fish, beans, nuts and poultry.

Made up of Amino Acids. Needed for the growth

and repair of body structures.

Hair and muscles. Provide energy.

Nucleic Acids:

The blue prints of organic chemicals.

Large compounds. Help to make proteins. DNA and RNA are Nucleic

Acids.

Energy Use: Metabolism: The

chemical reactions performed by a living organism. Needed for growth, to store energy, and repair cells.

Ingestion: How a living thing takes in or produces food.

Digestion: The process of breaking down food into simpler substances.

Energy continued:

Respiration: The process of a living thing taking in food to produce energy.

Excretion: The removal of waste products.

Response:

Stimulus, (Stimuli: plural): The signals to which an organism reacts.

Response: The action or movement or change caused by a stimulus.

Growth & Development

Growth: the process of becoming larger.

Development: the process of change that occurs during an organism’s life to produce a more complex organism.

Reproduction:

Sexual Reproduction: requires two parents. Most multicellular organisms reproduce this way.

Asexual Reproduction: reproduce with only one parent. Bacteria, yeast and some plants reproduce this way.

Changing an old theory:

Spontaneous Generation: Before the 1600’s people believed that life could spring from non-living things.

Francesco Redi: an Italian doctor in 1668 helped to disprove Spontaneous Generation.

Louis Pasteur

Mid-1800’s French Chemist Proved that Spontaneous

Generation was not true. He compared bacterial

growth in boiled and un-boiled broth.

Pasteurization

Needs of Living Things:

Food Water Living Space Stable Internal Conditions

Food

Autotroph: a kind of living thing that can make it’s own food. Auto means “self” and troph means “feeder”.

Heterotrophs: a kind of living thing that cannot make their own food. Hetero means “other”. They must obtain energy by feeding on others.

Stable Internal Conditions

Homeostasis: To maintain a stable internal condition. Organisms must be able to keep the conditions inside their bodies stable, even when conditions in the surroundings change.

Living Things:

Have all 6 characteristics of living things or have the potential to (seeds).

Cells Chemicals of Life Use Energy Respond to their

surroundings Grow and Develop Reproduce

Non-living Things:

Do not have all of the 6 Characteristics of living things. It may have some, but not all!

It may never have been alive (rock), OR

It may have been alive once (tree), but went through a chemical or physical process and was changed (chair).

Dead:

It once was alive, but no longer is.

It may still have cells or chemicals of life, but they no longer function.

The End

Created by Mrs. Scibelli

Science Explorer From Bacteria to Plants