BIOLOGY - Arizona State University

[Pages:17]BIOLOGY!

The Study of Life

bios = life ology = study of

What is LIFE?

I know it when I see it!

What are some characteristics we associate with the "definition" life?

What are the Properties of Life?

1. Precise organization (order) 2. Homeostasis 3. Response to the environment 4. Energy uptake and use 5. Growth and development 6. Reproduction 7. Ability to Evolve

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Properties of Life

1) Order

Properties of Life

2) Homeostasis

Properties of Life

3) Response to the Environment

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Properties of Life

4) Energy Processing

Properties of Life

5) Growth and Development

Properties of Life

6) Reproduction

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Properties of Life

7) Evolution & Adaptation

Properties of Life?

1. Precise organization (order) 2. Homeostasis 3. Response to the environment 4. Energy uptake and use 5. Growth and development 6. Reproduction 7. Ability to Evolve

Is It Alive? Why or Why Not?

Cologne Cathedral

Baby Chicken

Escherichia coli bacteria

Hoover Dam

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Levels of Organization:

Biosphere Ecosystems Communities

Populations

Organs or Organ

Individuals Systems

Levels of Organization:

Organs or Organ Systems

Tissues

Cells

Organelles

Molecules

Emergent Properties

?Each level of the biological hierarchy is more than merely the sum of its parts

?Emergent properties result from interactions among components at each level

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Emergent Properties.

Life itself is an emergent property

Cells are the simplest units of life.

?The cell is the lowest level of structure that has all of the properties or qualities we use to define life. ?Some organisms consist of a single cell, others are multicellular aggregates of specialized cells.

The first cells were observed and named by Robert Hooke in 1665 from a slice of cork.

Hooke's Compound Microscope "Observation XVIII" of

the Micrographia

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Anton van Leeuwenhoek, was the first to see single-celled organisms in pond water

and observe cells in blood and sperm.

Anton van Leewenhoek "No more pleasant site has met my eye than this!"

Van Leewenhoek`s simple microscope

Leeuwenhoek reported how in the plaque scraped from his teeth: "I then most always saw, with great wonder, that in the said matter there were many very little living animalcules, very prettily a-moving. The biggest sort. . . had a very strong and swift motion, and shot through the spittle like a pike does through the water."

In the mouth an old man who had reportedly never cleaned his teeth in his life: "an unbelievably great company of living animalcules, a-swimming more nimbly than any I had ever seen up to this time."

THE CELL THEORY

? In 1839, Matthais Schleiden and Theodor Schwann extrapolated from their own microscopic research and that of others to propose the cell theory.

? The cell theory postulates that cells are the basic unit of structure and physiology in all living things.

? One of the great paradigms of Biology... ? Cell Theory is to Biology as the Atomic Theory is to Physics ? But... Thought cells formed spontaneously... in a manner similar to

crystal growth

? In 1855, Rudolf Virchow extended the cell theory :

? New cells are produced by the division of existing cells.

? Critical process in reproduction, growth, and repair of multicellular organisms.

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? All cells are enclosed by a membrane that regulates the passage of materials between the cell and its surroundings.

? All cells contain DNA, the heritable material that directs the cell's activities.

? Two major kinds of cells - prokaryotic cells and eukaryotic cells - can be distinguished by their structural organization.

? The cells of the microorganisms called bacteria and archaea are prokaryotic. Do not contain organelles.

? All other forms of life have the more complex eukaryotic cells.

The continuity of life is based on heritable information in the form of DNA

? Biological instructions for life are encoded in DNA (deoxyribonucleic acid).

? DNA is the substance of genes.

Genomes (Human and Others)

? The entire "library" of genetic instructions that an organism inherits is called its genome.

? The genome of a human cell is 3 billion chemical letters long.

? The "rough draft" of the sequence of nucleotides in the human genome was published in 2001.

? Biologists are learning the functions of thousands of genes and how their activities are coordinated in the development of an organism.

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