the characteristics of life. i. history a. spontaneous generation or abiogenesis 1. 1 st proposed by...

The Characteristics of Life


I. History

A. Spontaneous Generation or Abiogenesis 1. 1st proposed by Aristotle

2. Believed that complex, living organisms are generated by decaying organic

substances, Ex. 1. that mice would spontaneously appear in stored grain

or

2. maggots spontaneously appear in meat.


I. HistoryA. Spontaneous Generation or Abiogenesis

3. Was widely believed until the 19th century.

4. Several scientists performed experiments that

disproved spontaneous generation • Francisco Redi

• Lazzaro Spallanzani

• Louis Pasteur

Pasteur’s Experiment

Louis Pasteur

1859

I. The Characteristics of Life B. Biogenesis

1. The process of life forms producing life forms of the same kind

Ex. a spider lays eggs, which hatch into spiders

2. The term is also used for the assertion that life can only be passed on by living things

I. The Characteristics of Life How can you tell if something is alive?

http://images.google.com/imgres?imgurl=www.drbobs.com/rock.jpg&imgrefurl=http://www.drbobs.com/Bigrock.htm&h=480&w=640&prev=/images%3Fq%3Drock%26start%3D40%26svnum%3D10%26hl%3Den%26lr%3D%26ie%3DUTF-8%26oe%3DUTF-8%26sa%3DN

http://www.prairienet.org/upd/artwork/ash-tree-at-APNC-2001.gif

http://images.google.com/imgres?imgurl=www.shiitake.net/images/shiitake/grade%25201%2520mushroom%2520on%2520block%2520(bottom).jpg&imgrefurl=http://www.shiitake.net/shiitake_mushroom_images.htm&h=640&w=480&prev=/images%3Fq%3Dmushroom%26start%3D40%26svnum%3D10%26hl%3Den%26lr%3D%26ie%3DUTF-8%26oe%3DUTF-8%26sa%3DN

The Characteristics of Life Interesting Fact:

Biologists have devised a list of 5 characteristics that define life.

Interesting Fact:

Something can be considered alive ONLY if it displays ALL 5 of the

characteristics


Anything that possesses all 5 of the characteristics of life is called an organism.

http://www.artglass-pottery.com/imagesF/iguana.jpg

II. The 5 Characteristics of Life

A. Cellular Organization

celltissueorgansystemorganism

B. Growth & Development

C. Reproduction

D. Adaptation to Environment

E. Maintenance of Homeostasis

I. The 5 Characteristics of Life

A. Cellular Organization

- “All living forms of life are made up of cells and become more organized from this basic unit of life”

Ex. -Cells form tissues

-Tissues form organs

-Organs form organ systems

http://images.google.com/imgres?imgurl=www.nanoartworks.com/images/Cell.jpg&imgrefurl=http://www.nanoartworks.com/nanomete.htm&h=191&w=170&prev=/images%3Fq%3Dcell%26svnum%3D10%26hl%3Den%26lr%3D%26ie%3DUTF-8%26oe%3DUTF-8

I. The 5 characteristics of life

• Does it grow?

Growth – an increase in the # of cells

making up an organism increases it’s size

• Does it develop?

Development – as cell #’s increase, they begin to diversify causing changes to take place throughout the the life span of the organism

B. Growth & Development

I. The 5 Characteristics of Life C. Reproduction

• All living organisms are able to reproduce themselves

• Even one cell organisms replicate themselves

http://www.darlenealleman.com/images/ducklings.jpg


D. Adaptation to Environment

• All living organisms are able to adapt to their surroundings.

• “to adapt” -- to be able to react or respond

- to something in the environment

- to a “stimulus”


E. Maintain Homeostasis

• All living organisms are able to maintain a relatively constant internal environment that is suitable for it’s life

Homeostasis - ?

“homo” + “static”


• An Amazing Fact: THE HUMAN BODY– A collection of a trillion, diverse and highly organized

cells

– Whatever it takes to keep this collection of a trillion cells “alive” = what it takes for you and I to stay alive!

WELCOME TO 21ST CENTURY H.S. BIOLOGY! A year of study to answer this question:

What DOES IT TAKE to keep cells alive?

the characteristics of life. i. history a. spontaneous generation or abiogenesis 1. 1 st proposed by...

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