Everyone is a Biologist !

Everyone is a Biologist !

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Chapter 1 What is Life?

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Today: Three Questions

What are the Characteristics of Life?

How diverse is life?

How do we study the natural world?

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All living things share the following characteristics in combination.

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1. Organization - Made of cells2. Reproduce3. Based on universal genetic code4. Grow and develop5. Obtain and use materials and energy6. Respond to their environment7. Maintain a stable internal environment –

metabolism8. Change over time

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ATOMMOLECULE

ORGANELLECELL

TISSUEORGAN

ORGAN SYSTEM

MULTICELLULAR ORGANISM

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Each level of biological organization exhibits emergent properties.

Ex. Capillaries transport blood (property not exhibited by

individual endothelial cells).

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Energy Use & MetabolismMetabolism - biochemical reactions that acquire & use energy.

Why do organisms need energy?How do organisms obtain energy?

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Maintenance of HomeostasisHomeostasis - the ability of an organism to maintain its internal environment despite conditions in the external environment.

Human body temperature is……… if body temperature rises, you sweat. if body temperature lowers, you shiver.

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Reproduction, Growth & DevelopmentAsexual reproduction - involves a single parent; progeny are genetically identical to the parent.Sexual reproduction - involves 2 parents; progeny are genetically diverse.

Is it essential for an individual to reproduce?

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Response & AdaptationIrritability - immediate response to a stimulus.

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Irritability & AdaptationAdaptation - an inherited behavior or characteristic that enables an organism to survive & reproduce.

Over time, adaptations are modified by natural selection.

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Life is always changing…..On the level of DNA……

Change = Evolution

Evolution is the backbone of biology.

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A Short Quiz:1. What are the characteristics of life?

2. What is homeostasis? What is an example of homeostasis?

3. Is a computer living? Why or why not? Is a virus living?

4. Why is energy required by living things?

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Life is Diverse

Biodiversity refers to the many different types of organisms on earth.

Taxonomy is the biological science that classifies life according to evolutionary relationships.

The Domain is the largest group of organisms.

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Life is Diverse

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Life is Diverse

Kingdom Phylum

Class Order

Family Genus

Species

Kids Pick Candy Over Fancy Green Salads

Francesco Redi’s Experiment Attempting to disprove Spontaneous Generation Common Beliefs of the Time

Frogs and Turtles come from mud and rotting wood.

Mice come from straw. Flies come from rotting meat. Most of these ideas remained from

the time of Aristotle. Why would people believe this?

Redi’s Experiment:Step 1

Redi knew that flies often appeared on and around rotting meat. So, he placed rotting meat in three jars.

Redi’s Experiment:Step 2

In the first jar, Redi left the jar open to the air.

Redi’s Experiment: Step 3

On the 2nd jar, Redi placed a cover on the jar. The flies could not smell the meat, nor could they land in the meat.

Redi’s Experiment: Step 4

On the 3rd jar, Redi placed a gauze or netting over the jar. The flies could smell the meat, but could not land on the meat.

Results?

What would you expect the results of this experiment to be?

Results

In the first jar, the flies could lay their eggs on the rotting meat, maggots would appear and later grow into flies.

In the second jar, the flies could not smell the meat, or land on it, so they would lay their eggs somewhere else.

In the third jar, the flies could smell the meat, so they would lay their eggs on the netting thinking there was a food source for the maggots.

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Everyone is a Biologist !