Neil A Campbell Brad Williamson Robin J Heyden

Neil A. Campbell • Brad Williamson • Robin J. Heyden Created by Roxanne Leitner

CONCEPT 1. 1 Biology explores life from the global to the microscopic scale. Objectives • Identify the major organizational levels of life.

CONCEPT 1. 1 Biology explores life from the global to the microscopic scale. Key Terms • biosphere • ecosystem • organism • cell • DNA • gene

Biosphere • all parts of the planet that are inhabited by living things • atmosphere • lithosphere • hydrosphere

• Flying foxes are becoming an endangered species, partly because of habitat destruction

Life in the Trees • The lives of gray-headed flying foxes are closely entwined with the lives of the eucalyptus trees that form their habitat • Eucalyptus trees provide food and roosting sites for the flying foxes • Flying foxes aid in eucalyptus pollination and help disperse the resulting seeds

The Scope of Biology • Biology is the scientific study of life • Interactions between different kinds of organisms affect the lives of all

Life’s levels of organization define the scope of biology • A structural hierarchy of life, from molecules • to ecosystems, defines the scope of biology An ecosystem consists of: • all organisms living in a particular area • all nonliving physical components of the environment that affect the organisms (soil, water)

Ecosystem • Ecosystems ECOSYSTEM LEVEL Eucalyptus forest include: • all the organisms in an area, which make up a community • interbreeding organisms of the same species, a population COMMUNITY LEVEL All organisms in eucalyptus forest POPULATION LEVEL Group of flying foxes ORGANISM LEVEL Flying fox ORGAN SYSTEM LEVEL Nervous system ORGAN LEVEL Brain Spinal cord Nerve TISSUE LEVEL Nervous tissue CELLULAR LEVEL Nerve cell MOLECULAR LEVEL Molecule of DNA Figure 1. 1

Organism • Organisms are ECOSYSTEM LEVEL Eucalyptus forest made up of: • organ systems • organs • tissues • cells • molecules • atoms COMMUNITY LEVEL All organisms in eucalyptus forest POPULATION LEVEL Group of flying foxes ORGANISM LEVEL Flying fox ORGAN SYSTEM LEVEL Nervous system ORGAN LEVEL Brain Spinal cord Nerve TISSUE LEVEL Nervous tissue CELLULAR LEVEL Nerve cell MOLECULAR LEVEL Molecule of DNA Figure 1. 1

Concept Check 1. 1 1. Which level of life includes all of the other levels in this list: organisms, cells, biosphere, molecules, ecosystems? Explain your answer. biosphere 2. Identify an ecosystem in the area where you live?

Concept Check 1. 1 3. What are genes? How are they related to DNA? genes – units of inherited information part of DNA molecule

CONCEPT 1. 2 Biology explores life in its diverse forms. Objectives • Use the term species in discussing life’s diversity. • Explain the basic strategy biologists use in classifying organisms. • Identify a characteristic that separates the domains Bacteria and Archaea from the domain Eukarya.

CONCEPT 1. 2 Biology explores life in its diverse forms. Key Terms • species • domain • unicellular • prokaryotic cell • eukaryotic cell • multicellular

Classifying Life: The Basic Idea taxonomy • study of classification species • organisms that look alike, can interbreed & produce fertile offspring

Levels of Classification • • Kingdom Phylum Class Order Family Genus Species

Three Domains • unicellular • prokaryotic cells – without nuclei or membranebound organelles 1. Domain Bacteria • Typical bacteria 2. Domain Archaea • live in harsh environments Figure 1. 4 A, B

3. Domain Eukarya • unicellular or • multicellular eukaryotic cells • nucleus • membrane-bound organelles • Kingdoms • Protista • Fungi • Plantae • Animalia Figure 1. 4 C-F

Concept Check 1. 2 1. Explain the relationship between the terms species and organism. 2. Explain two different ways that you could classify the following items: banana, lemon, sandwich, milk, orange, meatball, salad.

Concept Check 1. 2 3. Explain the main difference between organisms of the domains Bacteria and Archaea and organisms of the domain Eukarya. Bacteria, Eukarya – prokaryotes Eukarya - eukaryotes

CONCEPT 1. 3 Ten Themes unify the study of life. Objectives • Identify themes of biology.

CONCEPT 1. 3 Ten Themes unify the study of life. Key Terms • systems • photosystem • producer • consumer • homeostasis • adaptation • population • natural selection • evolution

Unity in diversity: All forms of life have common features • All organisms share a set of common features, signs of unity in life’s vast diversity • All are made of cells • All have DNA as their genetic blueprint • These orchids show the variety possible within one species Figure 1. 5 A

• DNA is made of chemical units called nucleotides • Each species has its own nucleotide sequence Figure 1. 5 B

• The genetic information in DNA underlies all of the features that distinguish life from nonlife • Order and regulation • Growth and development • Use of energy from the environment • Response to environmental stimuli • Ability to reproduce • Evolutionary change

Evolution explains the unity and diversity of life • Charles Darwin is a central figure in biology • He synthesized theory of evolution by natural selection • A theory in science is a comprehensive idea with broad explanatory power • Evolution is the core theme of biology Figure 1. 6 A

Natural Selection • The theory of natural selection explains the main mechanism whereby all species of organisms change, or evolve (1) Population with varied inherited traits (2) Elimination of individuals with certain traits Figure 1. 6 B (3) Reproduction of survivors

• Evolution happens when populations of organisms with inherited variations are exposed to environmental factors that favor the success of some individuals over others • Natural selection is the editing mechanism • Evolution is based on adaptations