Inquiry into LifeTwelfth Edition

Chapter 1

Lecture PowerPoint to accompany

Sylvia S. Mader

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

1.1 The Characteristics of Life

• Biology – Science of Living things– Bio – Life

• Logos – Word of, knowledge

• ** A laboratory science** You live in your own unique Lab (and you experiment all the time)

1.1 The Characteristics of Life• Life exists almost everywhere on the planet Earth.

1.1 The Characteristics of Life

• Life exists almost everywhere on the planet Earth.

• Earth possesses a great variety of diverse life forms.

1.1 The Characteristics of Life

• Life exists almost everywhere on the planet Earth.

• Earth possesses a great variety of diverse life forms.

• All living things have certain characteristics in common.

Living Things:

• Are organized• Acquire materials and energy• Reproduce• Respond to stimuli• Are homeostatic• Grow and develop• Have the capacity to adapt

1.2 The Classification of Living Things

• Science of Taxonomy - Classification of living organisms based on similarities

• Not exciting, not fun, but sometimes we have to “Just do It”

• Hierarchical – from top to bottom• A specific name for an organism, like

Homo sapiens or E. coli, represents the very specific type of organism – bottom of scheme

1.2 The Classification of Living Things

• Living organisms are assigned to groups based upon their similarities.

• Systematics is the discipline of indentifying and classifying organisms.

Domains

• The highest – largest category, recent addition• 3 domains

– 1. Archaea – ancient “bacteria”, unicellular like bacteria, also simple cell structure (prokaryote – no nucleus) but have distinct metabolism (chemistry) allowing them to exist in “extreme” environments

– 2. Bacteria – unicellular, prokaryote, found everywhere

– 3. Eukarya – unicellular to multicellular, complex and organized cells with nuclei and organelles (mitochondria)

Domain Archaea

• Archaea are single- celled organisms that lack a membrane-bound nucleus. - Prokaryote

• Archaea can be found in environments that are too hostile for other life forms.

Domain Bacteria

• Bacteria are single- celled organisms that lack a membrane-bound nucleus. (Prokaryote also)

• Bacteria are found almost everywhere on the planet Earth.

Domain Eukarya• The cells of all eukaryotes have a membrane-

bound nucleus. Members of the Domain Eukarya are further categorized into one of

four Kingdoms. (know these kingdoms)

Categories of Classification

Domain

Kingdom

Phylum

Class

Order

Family

Genus

Species

Categories of Classification

Domain - Dumb

Kingdom - King

Phylum - Philip

Class – Came

Order - Over

Family - For

Genus - Good

Species - __

Spaghetti?

Categories of Classification

DomainKingdomPhylumClassOrderFamilyGenusSpecies Least inclusive

Most inclusive

Categories of Classification

Scientific Names

• Binomial (two name) Genus first and first letter capitalized, then species not capitalized. If written or typed – either underline or italicize– Genus name, species name – Homo sapiens - italicized– Homo troglodytis (Your EX?) – underlined– Canis familiaris – Your puppy (except poodles)– Felis domesticus – Your Kitty (some strange people

have to have Felis leo or Felis tigris)– Canis latrans – Invites your kitty over for lunch– Canis lupus - ____________? guess

Know for test

• 3 domains Archaea, Bacteria, Eukarya

• 4 Eukarya Kingdoms– Protista – Protozoans like Ameba and

Paramecium (producers and consumers)– Fungi – yeasts, molds, mushrooms

(consumers)– Plants – complex producers, trees, grasses– Animals – complex consumers

1.3 The Organization of the Biosphere

• Biosphere – The zone of air, land, and water at the surface of the Earth

where living organisms are found.

• Population (groups of individuals of a species in a given area)

• Community (populations of different species that interact)

• Ecosystem (interactions of communities plus the

physical habitat)

Ecosystems

Ecosystems are characterized by:

Chemical cycling - carbon, hydrogen, oxygen, nitrogen, phosphorus, etc.

Energy flow – light, to chemical energy, to heat

Ecosystems

The Human Species

• Humans depend on healthy ecosystems for our own survival.

• The human species modifies ecosystems for own purposes.

• Preservation of ecosystems is important to ensure our continued existence.

Biodiversity

• Total number of species• 30 million different species?

– The variability in their genes• Remarkably genetically similar - genomics

– The ecosystems in which they live – many ecosystems are adversely affected by humans (our recent vacation to St. Johns revealed significant change in the coral reef ecosystem) *enjoy, but “tread lightly”)

A Coral Reef Ecosystem

Ecosystems

• The Earth may be losing as many as 400 species per day due to human activities.

1.4 The Process of Science

• Biology is the scientific study of life.

• The process of science uses the scientific method.

Flow Diagram of the Scientific Method (know for test)

Scientific Theory

• A scientific theory is a concept supported by a broad range of observations, experiments, and conclusions.

Examples of Theories in BiologyKnow for test

• See pg 11• Cell – all life is “cellular”, new life comes from

previous cells (viruses, prions?)• Homeostasis – stable internal environment• Gene – code, units of heredity, DNA• Ecosystem - organisms within an environment

are interrelated (circle of Life – hakuna matata)• Evolution – organisms genetically change, and

pass genes on to offspring, best fit to survive

The Process of Science

A Controlled Study• Experiments in controlled studies have two

types of groups:

• Control Group (for comparison)

• Experimental Group ( 1 variable manipulated)

The Process of Science

A Controlled Study• Variables

– The experimental variable (independent variable) is manipulated by the investigator. All other factors remain identical.

The Process of Science

A Controlled Study• Variables

– The experimental variable (independent variable) is manipulated by the investigator. All other factors remain identical.

– The response variable (dependent variable) represents the result of the manipulation of the experimental variable. (what we are testing for and hope to “quantify” mathematically)

An Experiment

• HYPOTHESIS: A pigeon pea/winter wheat rotation will cause winter wheat production to increase as well as or better than the use of nitrogen fertilizer. Read on your own. Boring!!!!!

An Experiment

• HYPOTHESIS: A sustained pigeon pea/winter wheat rotation will eventually cause an increase in winter wheat production.

• PREDICTION: Wheat biomass following two years of pigeon pea/winter wheat rotation will surpass wheat biomass following nitrogen fertilizer treatment.

An Experiment

An Experiment - Note: data is quantified and expressed graphically

An Experiment

• Conclusion: The hypothesis was supported. At the end of two years, the yield of winter wheat following a pigeon pea/winter wheat rotation was better than for the other type pots.

1.5 Science and Social Responsibility

• Technology is the application of knowledge for a practical purpose. $$$$$ DNA studies, genomics, antibiotics, chemotherapy, computers, automobiles, Hydrogen fuel cells

• Technology has both benefits and drawbacks. DDT use and prevention of malaria – raptors lay soft eggs

• Ethical and moral issues surrounding the use of technology must be decided by everyone. • Eugenics – gene manipulation, only the white, or bright, or the

useful are allowed (cloning?)