What is this?

How is a hurricane like a living thing?

How is a hurricane like a living thing? organized uses energy circulation grows limited existence

Inside the eye of hurricane George

Concept of Life

How do we know when something is alive? How do we know when it’s dead? Think of instances where it is hard to tell if something is living or non-living.

Functional MRI

Terry Schiavo

Viruses

Water Bears

http://www.youtube.com/watch?v=v2Zfdmie4hA Water bears most extreme 4:39

A. Definition of Life Scientists have not been able to agree upon a single, simple definition of life. Living organisms perform certain functions that are taken to be the characteristics of life.

Herpes Virus

Living things are called organisms. All organisms share certain characteristics.

Characteristics of Organisms Highly organized contain many complex chemical substances. Made up of one or more cells.

Use energy. Have a definite form & a limited size. Have a limited life span. Grow.

Respond to changes in the environment. Able to reproduce. Groups of living things evolve, or change over time.

HOMEOSTASIS! The condition of a constant internal environment. Occurs when all life processes are in balance.

Living Things Carry Out Many Processes What are some things organisms do?

Nutrition Process of taking in materials (nutrients) from the external environment and changing them into usable forms.

2 Types of Nutrition Autotrophs – make their own nutrients (plants & some bacteria) Heterotrophs – must get nutrients from the environment (humans)

What life process is depicted below?

What life process is depicted below? Pooping is NOT excretion! What kind of waste is being removed during pooping? Pooping (Egestion) is the removal of undigested waste

Egestion is the removal of undigested waste Excretion is the removal of metabolic waste

So…. what life process is pooping part of?

Nutrition includes: Ingestion – taking in food. Digestion – break down of food into smaller, usable pieces. Egestion – (defication) removal of undigested waste

Which life process is related to a plant that has shriveled because of a lack of water? nutrition Why isn’t the answer “regulation”?

Why isn’t the answer “regulation”? The plant didn’t “do anything” that resulted in the shriveling. Regulation involves mechanisms that do opposing actions to maintain dynamic equilibrium

Growth, Synthesis, Regulation A cut heals when skin cells multiply. Which life process is involved? Growth, Synthesis, Regulation Why isn’t this example considered reproduction? It does not produce a new individual organism

Which life process is involved when a plant such as poison ivy makes a toxin? synthesis

Dinosaurs became extinct millions of years ago Dinosaurs became extinct millions of years ago. Which life process was there a lack of? reproduction

Transport The process by which substances enter and leave cells and become distributed within cells (circulatory system).

Respiration Process of releasing chemical energy stored in nutrients. Not breathing! Can occur in presence or absence of oxygen.

What life process is illustrated here?

Synthesis Making more complex substances from simpler ones

Growth Process by which living things increase in size as a result of growth in individual cells or in the number of cells.

Excretion Process of ridding the body of wastes. Sweating, urinating, exhaling. NOT pooping!

Regulation All activities that help to maintain homeostasis. Involves the nervous and endocrine systems (brain, spinal cord, nerves, hormones).

Reproduction Process by which living things produce new organisms of their own kind. Not necessary for the survival of an individual, but is necessary for survival of a species.

Special Case - Metabolism All chemical reactions occurring within the cells of an organism.

Metabolism includes processes that breakdown substances as well as those that build substances. The single most important characteristic of life!