Biology 1 Topics 1 and 2- Concept and Manifestations of Life

Biology is the study of life

Topic 1

A. Manifestations and Characteristics of Life B. Theories on the Origin of Life

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The Concept of Life

What is LIFE?

• Most contemporary biologists define life as a particular set of processes that result from the organization of matter

Characteristics of All Forms of Life

All forms of life share common properties/characteristics 1. Organization and Order—the highly ordered structure that typifies life

Growth and development

Organization and Order

Reproduction Energy processing

Response to the environment

Homeostasis

2. Energy processing—the use of chemical energy to power an organism’s activities and chemical reactions 3. Metabolism/Homeostasis—an ability to control an organism’s internal environment 4. Response to the environment/Movement—an ability to respond to environmental stimuli

Evolutionary adaptation

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Biology 1 Topics 1 and 2- Concept and Manifestations of Life

Manifestations and Characteristics of Life 5. Reproduction—the ability of organisms to reproduce their own kind

1. Life is highly organized (ORGANIZATION).

6. Growth and development—consistent growth and development controlled by inherited DNA 7. Evolutionary adaptation— variation, change and adaptation

Biosphere

Regions of the Earth’s crust, water and atmosphere inhabited by living things

Ecosystem

Community plus the physical environment

Community

Interacting populations in a particular area

Population

Organisms of the same species in a particular area

Organism

Organism’s Organization and Order

Ecosystem: Forest in Madagascar

Biosphere Madagascar

• characteristics of life emerge from an organism’s organization

Community: All organisms in the forest

Population: Group of ring-tailed lemurs

Individual containing organ systems Organism: Ring-tailed lemur

Organ system

Composed of several organs functioning together

Organ

Group of tissues functioning together for a specific task

Tissue

Group of cells with common structure and function Structural and functional unit of living things; consists of organelles Specialized structure composed of complex molecules within a living cell

Cell Organelle Molecule Atom

Union of two or more atoms of the same or different element Smallest unit of an element composed of electrons, protons and neutrons

Spinal cord Organ system: Nervous system Brain

Organ: Brain

Nerve

Tissue: Nervous tissue

Cell: Nerve cell

Atom

Nucleus

Organelle: Nucleus

Molecule: DNA

Manifestations and Characteristics of Life

Manifestations and Characteristics of Life

2. Life requires a constant input of energy and raw materials (METABOLISM).

3. Life has strong internal control (HOMEOSTASIS)

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Biology 1 Topics 1 and 2- Concept and Manifestations of Life

Manifestations and Characteristics of Life

Manifestations and Characteristics of Life

4. Life reacts to the environment (IRRITABILITY & MOVEMENT).

5. Life reproduces itself (REPRODUCTION).

Irritability is a state of extreme sensitivity to stimulation of any kind.

Manifestations and Characteristics of Life

Manifestations and Characteristics of Life

6. Life grows (GROWTH & DEVELOPMENT).

7. Life varies and evolves (ADAPTATION & EVOLUTION).

Manifestations and Characteristics of Life 7. Life varies and evolves (ADAPTATION & EVOLUTION).

How did life BEGIN? African wild dog

Coyote

Fox

Wolf

Jackal

Thousands to millions of years of natural selection

Ancestral canine

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Biology 1 Topics 1 and 2- Concept and Manifestations of Life

Theories on the Origin of Life

• Louis Pasteur’s 1862 experiment disproves abiogenesis

1. ABIOGENESIS / SPONTANEOUS GENERATION •Life was created spontaneously from lifeless or inorganic matter

www.fotosearch.com/comp/ITS/ITS223/itf139053.jpg

Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

Theories on the Origin of Life

Theories on the Origin of Life

2. BIOGENESIS

3. SPECIAL CREATION

•Life comes from pre-existing life

http://www.artoftheprint.com/jpegimages/rausch_anton_mother_and_child.jpg

•Life was created by supernatural or divine forces

www.bibledirectories.com/.../What-is-it.html

Theories on the Origin of Life

Theories on the Origin of Life

4. INTERPLANETARY / COSMOZOIC THEORY

5. BIOGEOCHEMICAL THEORY

•Life originated on a distant planet •Also known as PANSPERMIA

•Life evolved from inorganic matter •Chemical and physical processes in Earth’s primordial environment eventually produced simple cells.

Panspermia Theory suggests that life seeds came from outer space and planets exchanged life. http://www.rogerwendell.com/images/evolution/dmns_recipe_for_life_09-02-2006.jpg

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Biology 1 Topics 1 and 2- Concept and Manifestations of Life

Debates about the origin of life abounds

Time Line of Life on Earth

• Laboratory simulations cannot prove that these kinds of chemical processes actually created life on the primitive Earth. • They describe steps that could have happened. • The origin of life is still subject to much speculation and alternative views. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

• Alternatively, we can view the time line with a clock analogy.

Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

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