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

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 Life in the Trees

Biology is the scientific study of life Interactions between different kinds of organisms affect the lives of all 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) Life’s levels of organization define the scope of biology

Ecosystem Ecosystems include: all the organisms in an area, which make up a community interbreeding organisms of the same species, a population ECOSYSTEM LEVEL Eucalyptus forest 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 Brain Spinal cord Nerve TISSUE LEVEL Nervous tissue CELLULAR LEVEL Nerve cell MOLECULAR LEVEL Molecule of DNA Figure 1.1

Organism Organisms are made up of: organ systems organs tissues cells molecules atoms ECOSYSTEM LEVEL Eucalyptus forest 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 Brain Spinal cord Nerve TISSUE LEVEL Nervous tissue CELLULAR LEVEL Nerve cell MOLECULAR LEVEL Molecule of DNA Figure 1.1

Concept Check 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 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 membrane- bound organelles 1. Domain Bacteria Typical bacteria Figure 1.4A, B 2. Domain Archaea live in harsh environments

Figure 1.4C-F 3. Domain Eukarya unicellular or multicellular eukaryotic cells nucleus membrane-bound organelles Kingdoms Protista Fungi Plantae Animalia

Concept Check 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 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 the 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

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 Unity in diversity: All forms of life have common features Figure 1.5A

DNA is made of chemical units called nucleotides Each species has its own nucleotide sequence Figure 1.5B

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

Charles Darwin is a central figure in biology He synthesized the 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 Evolution explains the unity and diversity of life Figure 1.6A

Natural Selection The theory of natural selection explains the main mechanism whereby all species of organisms change, or evolve Figure 1.6B (1) Population with varied inherited traits (2) Elimination of individuals with certain traits (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

Concept Check Using examples describe three biology themes. 2. Describe four ways you have interacted with your environment today.

Concept Check In biological terms are you a producer or consumer? Explain your answer.