1.charac oflife

Everyone is a Biologist !

Chapter 1 What is Life?


Today: Three Questions

What are the Characteristics of Life?

How diverse is life?

How do we study the natural world?



All living things exhibit six characteristics in combination.

CHARACTERISTICS OF LIFE

• 1. Organisms are composed of cells

• 2. Organisms grow and develop

• 3. Organisms regulate their metabolic processes

• 4. Organisms respond to stimuli

• 5. Organisms reproduce

• 6. Populations evolve and become adapted to the environment


Each level of biological organization exhibits emergent properties.

Ex. Capillaries transport blood (property not exhibited by

individual endothelial cells).



Energy Use & Metabolism

Metabolism - biochemical reactions that acquire & use energy.

Why do organisms need energy?

How do organisms obtain energy?



Maintenance of Homeostasis

Homeostasis - 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.



Reproduction, Growth & Development

Asexual 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?



Irritability & Adaptation

Irritability - immediate response to a stimulus.



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

Over time, adaptations are modified by natural selection.



Life is always changing…..

On the level of DNA……

Change = Evolution

Evolution is the backbone of biology.


BIOLOGICAL ORGANIZATION

ATOM

MOLECULE

ORGANELLE

CELL

TISSUE

ORGAN

ORGAN SYSTEM

MULTICELLULAR ORGANISM


BIOLOGICAL ORGANIZATION



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?


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.


Life is Diverse


Life is Diverse

Kingdom Phylum

Class Order

Family Genus

Species

Kings Play Chess On Funny Green Squares


Life is Diverse

Human classification scheme:

Domain Eukarya

Kingdom Animalia

Phylum Chordata

Class Mammalia

Order Primates

Family Hominidae

Genus & species Homo sapiens


Life is Diverse

A Short Quiz:1. What is the order of classification?

2. Which has more critters: an order or a genus?

3. What is taxonomy?

4. The scientific name includes the _____ and _____ name.


How do we study the Natural World?

What is the Scientific Method?

Methodical exploration

What makes science unique!

Involves a series of ordered steps & is a framework that most scientists use.



Question

Hypothesis

Prediction

Observations

Now What???



Question

Hypothesis

Prediction

Observations

Experiment

• Experiment

• Results

• Interpretation & Conclusions



After you perform your experiment, you need to analyze the generated data. Does the data support or not support your hypothesis?

If your data does not support the hypothesis then……

If your data does support your hypothesis……..



What is difference between hypothesis, theory & law?

Hypothesis - “an educated guess”; a tentative explanation of phenomena.

Theory - a widely accepted explanation of natural phenomena; has stood up to

thorough & continual testing.

Law - a statement of what always occurs under certain conditions.



How is a control group different from an experimental group?

What is a double-blind study?

1.charac oflife

Technology

characteristics of life

natural world

doubleblind study

largest group of organisms

diverse biodiversity

use energy

different types of organisms

data support