UNIFYING THEMES OF BIOLOGY Copyright 2009 Pearson Education

1. Cells are the structural and functional units of life § Two distinct groups of cells exist – Prokaryotic cells – Simple and small – Bacteria are prokaryotic – Eukaryotic cells – Possess organelles separated by membranes – Plants, animals, and fungi are eukaryotic Copyright © 2009 Pearson Education, Inc.

Prokaryotic cell DNA (no nucleus) Membrane Nucleus (contains DNA) Organelles Eukaryotic cell

1. Cells are the structural and functional units of life (continued) § Unicellular organisms

1. Cells are the structural and functional units of life (continued) § Form generally fits function – By studying a biological structure, you can determine what it does and how it works (from molecules to organisms!) – Life emerges from interactions of structures – Combinations of structures (components) provide organization called a system Copyright © 2009 Pearson Education, Inc.

Form and Function

2. In life’s hierarchy of organization, new properties emerge at each level § Life’s levels of organization define the scope of biology § Life emerges through organization of various levels § With addition of each new level, novel properties emerge—called emergent properties Copyright © 2009 Pearson Education, Inc.

Biosphere Ecosystem Florida coast Community All organisms on the Florida coast Population Group of brown pelicans Organism Brown pelican Spinal cord Nerve Organ system Nervous system Brain Organ Brain Tissue Nervous tissue Cell Nerve cell Atom Nucleus Organelle Nucleus Molecule DNA

Biosphere Ecosystem Florida coast Community All organisms on the Florida coast Population Group of brown pelicans Organism Brown pelican

Organism Brown pelican Spinal cord Nerve Organ system Nervous system Brain Organ Brain Tissue Nervous tissue Atom Cell Nerve cell Nucleus Organelle Nucleus Molecule DNA

3. Stability and Homeostasis § Organisms must regulate their internal environment to survive in diverse ecosystems. § Behaviors and adaptations can help maintain homeostasis What are some examples? § Regulation occurs at every level of organization Copyright © 2009 Pearson Education, Inc.

Application: How does your body regulate temperature?

4. Reproduction and Inheritance § Organisms pass their traits from one generation to the next generation via reproduction. § DNA is the molecular basis of life (ALL life on Earth) DNA RNA Protein § The inheritance of genetic material through reproduction explains the continuity of life Copyright © 2009 Pearson Education, Inc.

4. Reproduction and Inheritance (continued) § Continuity of life is based on heritable information in the form of DNA § DNA–the genetic material–carries biological information from one generation to the next

5. Metabolism § Organisms have methods of capturing matter and energy (photosynthesis in plants) and using matter and energy (respiration in ALL organisms) § The process of regulating biochemical reactions is called metabolism. Copyright © 2009 Pearson Education, Inc.

5. Metabolism (continued) § Life is an open system that depends on energy transfer § Organisms continuously interact with the environment § Stuff comes in stuff goes out § Energy is used What happens to the consumers when they die?

6. Living organisms interact with their environments, exchanging matter and energy § Species rely on one another and their environment § Life requires interactions between living (biotic) and nonliving (abiotic) components – Photosynthetic organisms provide food and are called producers – Organisms that eat plants or other organisms are called consumers § The nonliving components are chemical nutrients required for life Copyright © 2009 Pearson Education, Inc.

(PRODUCERS)

7. EVOLUTION--THE CORE THEME OF BIOLOGY “Nothing in biology makes sense except in the

7. Evolution § Evolution explains the unity and diversity of life. § Unity u What do organisms have in common? u Why do similarities exist? § Diversity u Are there differences between organisms of the same species?

§ Unity § Shared genetic code § Evolutionary relationships § Connected through a common ancestor § Diversity § Differences in DNA structure among organisms § Natural selection: selection of some DNA structures over others § Adaptations: naturally selected traits

§ Natural selection was inferred by connecting two observations § Individuals within a population inherit different characteristics and vary from other individuals § A particular population of individuals produces more offspring than will survive to produce offspring of their own (Lamarckian evolution and giraffes) Copyright © 2009 Pearson Education, Inc.

In this example: • Dark-colored beetles are selected for • Light-colored beetles are selected against • Predation is the selective agent • Dark coloration becomes an adaptation for this population of beetles 1 Population with varied inherited traits 2 Elimination of individuals with certain traits 3 Reproduction of survivors

§ Natural selection is an editing mechanism – It results from exposure of heritable variations to environmental factors that favor some individuals over others – Over time this results in evolution of new species adapted to particular conditions/environments – Evolution is biology’s core theme and explains unity and diversity of life Copyright © 2009 Pearson Education, Inc.

The Three-Domain System Protists Plants Fungi Animals

Domain Eukarya Domain Bacteria (multiple kingdoms) Protists (multiple kingdoms) Kingdom Plantae Kingdom Fungi Kingdom Animalia Domain Archaea (multiple kingdoms)

YOU ARE HERE Dr. R. M. Moody

Characteristics of Life Copyright © 2009 Pearson Education, Inc.

1. 4 The unity of life: All forms of life have common features § All living things share common properties – Cellular Organization—All organisms composed of one or more cells; cells are organized to play certain roles in organisms. – Response to stimuli—Ability of organisms to respond to their environment. – Homeostatis—an ability to maintain an internal environment consistent with life – Metabolism—acquiring energy and transforming it to a form useful for the organism Copyright © 2009 Pearson Education, Inc.

1. 4 The unity of life: All forms of life have common features § Common properties continued – Growth and development—consistent growth and development controlled by DNA – Reproduction—the ability to perpetuate the species – Evolutionary adaptation—acquisition of traits that best suit the organism to its environment Copyright © 2009 Pearson Education, Inc.

(1) Cellular Organization (2) Regulation (5) Response to the environment (3) Growth and development (4) Energy processing (6) Reproduction (7) Evolutionary adaptation