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Characterist ics of Life Mrs. Stewart Honors Biology I

Characteristics of Life Mrs. Stewart Honors Biology I

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Page 1: Characteristics of Life Mrs. Stewart Honors Biology I

Characteristics of Life

Mrs. StewartHonors Biology I

Page 2: Characteristics of Life Mrs. Stewart Honors Biology I

Objectives Define life in terms of the scientific

characteristics that identify living organisms

Evaluate specimens for those characteristics

All living things are composed of cells that perform the necessary functions of life

Standard:

Page 3: Characteristics of Life Mrs. Stewart Honors Biology I
Page 4: Characteristics of Life Mrs. Stewart Honors Biology I

What is biology?

Bio logy

Life Study of

Page 5: Characteristics of Life Mrs. Stewart Honors Biology I

Define Life

Biologists have formulated a list of characteristics by which we can identify and classify living vs. non-living specimens

Page 6: Characteristics of Life Mrs. Stewart Honors Biology I

Characteristics of LifeCells and OrganizationHomeostasisResponse to StimuliMetabolismGrowth and DevelopmentReproductionChanges over time (adaptation)

***Organisms must have all seven characteristics in order to be considered alive***

Page 7: Characteristics of Life Mrs. Stewart Honors Biology I

Cells Basic units of structure

and function for all living things

Every organism consists of at least one cell

Organism = an individual that possesses all characteristics of life

Page 8: Characteristics of Life Mrs. Stewart Honors Biology I

Cells and Organization

Unicellular – made up of only one cell

Multicellular – consist of more than one cell

Page 9: Characteristics of Life Mrs. Stewart Honors Biology I

Levels of Organization - Living things have order and complexity not found in lifeless objects.

Living things are organized on several levels. Each level higher up on the hierarchy represents an increase in complexity.

Page 10: Characteristics of Life Mrs. Stewart Honors Biology I

Think – Pair - Share

Monkeys – summarize the heirarchy of organization found in complex organisms to your dog

Page 11: Characteristics of Life Mrs. Stewart Honors Biology I

Think – Pair - Share

Dogs – Both cells and organisms share the characteristics of life. Tell your monkey how cells and organisms different.

Page 12: Characteristics of Life Mrs. Stewart Honors Biology I

Response to stimuli Organisms respond to a stimuli in order

to maintain homeostasis Senses: make observations that lead to

responses

Reflexes: unconscious responses to

stimuli

Behaviors: learned and instinctive

responses to stimuli

Page 13: Characteristics of Life Mrs. Stewart Honors Biology I

Stimulus = a physical or

chemical change in the internal or

external environment.

LightTemperature

chemical

mechanical

Page 14: Characteristics of Life Mrs. Stewart Honors Biology I

Think – Pair – Share

Dogs Give an example of a reflex

response to stimuli

Monkeys Give an example of a

learned behavior response to stimuli

Page 15: Characteristics of Life Mrs. Stewart Honors Biology I

Homeostasis

Ability to maintain a stable internal environment

Examples: Heart rate Body temperature pH levels Water levels Others?

Homeostasis – body temperature explanation

Page 16: Characteristics of Life Mrs. Stewart Honors Biology I

Think – Pair – Share

Brainstorm together: why is homeostasis important for an organism’s survival?

Page 17: Characteristics of Life Mrs. Stewart Honors Biology I

Metabolism

The sum of all chemical reactions in the body

Some substances are broken down to yield energy and some substances are synthesized, which requires energy.

Page 18: Characteristics of Life Mrs. Stewart Honors Biology I

Metabolism (aka: energy use)

Organisms obtain energy by one of 2 methods:

Autotrophic – organisms that make their own food that they will then convert into energy (ex: photosynthesis)

Heterotrophic – organisms that must take in food from an outside source to convert into energy (examples???)

Page 19: Characteristics of Life Mrs. Stewart Honors Biology I

Growth

Growth occurs in two ways: 1) cell enlargement

– gets bigger 2) cell division

(reproduction) – cells split to produce more cells

Page 20: Characteristics of Life Mrs. Stewart Honors Biology I

Development

Development: process by which an organism becomes a mature adult through cell differentiation, or specialization.

Page 21: Characteristics of Life Mrs. Stewart Honors Biology I

Reproduction Process by which an organism produces

offspring

Asexual-One parent

-Genetically

identical offspring

(Examples:

budding & fission)

Sexual-requires 2 parents

-genetically different offspring

-sex cells from each

gender join

Page 22: Characteristics of Life Mrs. Stewart Honors Biology I

Heredity Living things

inherit traits from their parent(s)

Genes = basic unit of inheritance

DNA molecules contain genes that code for proteins which are important for proper functioning of an organism

Page 23: Characteristics of Life Mrs. Stewart Honors Biology I

Change through time

Adaptations – changes made by a population in response to the environment in order to survive.

Why do organisms adapt?

SURVIVAL

Page 24: Characteristics of Life Mrs. Stewart Honors Biology I

Assignment Characteristics of life Scavenger Hunt

Page 25: Characteristics of Life Mrs. Stewart Honors Biology I

Reflection - Exit Ticket Which of the 7 characteristics do you

think is the most important one to define life.

Explain your choice.