The text (Raven and Johnson, Biology) defines two principles of biology in chapter 1. These two principles will
- 1. Living organisms are historical entities, and can best be understood as being historically related to one another.
- 2. Living organisms display many levels of organization, from the molecular to the ecological. These levels are connected by genetic information, which is both a record of their history, and the reference book for their operation.
Introduction Unit 1 Unit 2 Unit 3 Unit 4 Introduction: Accounting for Organismal Diversity
Scientists learn about organisms by proposing and testing hypotheses about them. Similarities between organisms makes information from one organism applicable to others as well. Evolutionary theory suggests that all organisms are related, and that groups of similar organisms are the descendants of some common ancestral population.
- How scientists think about organisms
- Diverse organisms display biochemical similarity
I. Organismal diversity is built on a common molecular base.
Organismal diversity is, paradoxidally, rooted in a shared molecular structure. This implies that many types of molecules are older than the species that house them. Biologically important molecules are composed primarily from a few small atoms. Although the macromolecules that characterize living organisms are complex, most are formed by combinations of only a few types of subunits. Exam I
- Small covalently linked atoms are used for constructing biomolecules
- Ions are important for metabolic function
- Water has unique properties important for living organisms
- A carbon backbone is the basis for biomolecules
- Biomolecules contain a few important functional groups
- Biomonomers are used as subunits for macromolecular structure
- Monomers combine to make macromolecules
- Proteins are composed of amino acids
- Proteins fold into a functional form
- Surface interactions are important for protein function.
- Carbohydrate polymers are important structural and nutritional molecules
- Lipids serve as structural and nutritional molecules
- Mononucleotides are the basis for both energy storing molecules and informational molecules.
- ATP is an energy reservoir
- DNA and RNA are informational reservoirs
II. Cell and organismal structure reflects genetic information.
Cells are macromolecular organizational structures of which most organisms are composed. Specific cell functions are associated with specific organelles. Genetic information for cellular and organismal structure is in the nucleus. Genetic information within organisms is conserved by mitosis. Genetic character of a population is diversified by meiosis and recombination. Inheritance in diploid organisms produces various combinations of maternal and paternal genes. The development of an individual from a fertilized egg depends both on genetic information and on cellular interactions. Exam II
- The cell theory is one of the important organizing principles of biology.
- Bacteria and eukaryotes have different kinds of cells.
- Eukaryotic cells have nuclear and cytoplasmic domains.
- Cells have organelles specialized for macromolecular synthesis, processing and storage, energy transductions, cell shaping and motility and cell junctions.
- Macromolecular synthesis is required for cell and organismal growth
- Proteins are assembled on ribosomes and distributed to membranous organelles.
- The information for protein structure is encoded in DNA.
- Eukaryotic cells have a regular cell cycle.
- New chromosomes replicate by copying old ones.
- Mitosis ensures genetic fidelity in asexual reproduction and growth.
- Mitosis is used for asexual reproduction in unicellular organisms and growth and replacement of tissues in multicellular organisms.
- Biparental inheritance combines chromosomes of two individuals.
- In meiosis, each parent contributes only half of its chromosomes to progeny.
- Meiosis generates many possible combinations of parental chromosomes
- Sexual reproduction produces progeny that are not identical.
- Laws of inheritance for sexually reproducing organisms were discovered by Mendel
- Some genes don't follow all of Mendel's Laws.
- The Human Genome Project has revealed many interesting features of human genes.
- Multicellular organisms develop from fertilized eggs.
- All animals develop similarly.
- Fertilizations activates the process of development.
- Cleavage segregates different cytoplasmic territories in the egg.
- In gastrulation, cells interact to produce new tissues.
- Each embryonic tissue gives rise to specific adult tissues
- Organismal diversity arises from changes in development.
III. Modern organisms are grouped into three biotic domains: Archaea, Eubacteria, and Eukaryotes.
Darwin proposed the Theory of Natural Selection to account for species diversity and geographical variation. The modern concept of evolution includes microevolution, speciation and macroevolution. . Linnaeus named and organized species into a hierarchical classification system. Modern classification systems reflect phylogenetic relationships. Modern organisms are grouped into three major lineages: the archaea, the eubacteria, and the eukaryotes. Eukaryotes seem to have arisen from symbiotic assemblages of prokaryotic ancestors. All major animal body plans are represented in fossils of the early Cambrian period. The most successful animal groups demonstrate a number of evolutionary innovations.
- Evolutionary theory, which claims that organisms are related through common ancestry, is one of the major organizing principles of biology.
- Evolution includes microevolution, speciation, and the generation of novel structures.
- Darwin proposed that Natural Selection could explain both geographical variation and speciation.
- Mayr's Biological Species Concept defines a species as being a reproductively isolation population.
- Linnaeus introduced the binomial system for naming species and a hierarchical classification for grouping them into higher taxa.
- The most commonly used taxa for grouping animals above the species level are: genus > family > order > class > phylum > kingdom.
- Modern classification systems are phylogenetic, reflecting the evolutionary relationships among species.
- Cladistic systems try to identify monophyletic taxa, in which all members of a given taxon are descended from the same common ancestor.
- Some historical taxa are not monophyletic.
- Genetic comparisons can help to resolve classification puzzles.
- Life on earth originated about 4 billion years ago.
- Three domains of organisms have been identified: archaea, bacteria, and eukaryotes.
- Bacteria are the oldest and most abundant life forms on earth.
- Bacteria exhibit both structural and metabolic complexity.
- The eukaryotic cell may have originated as an interdependent population of prokaryotic cells.
- Some bacteria are similar to eukaryotic mitochondria and chloroplasts.
- Living protozoans demonstrate a number of different nuclear and cytoplasmic specializations.
- All multicellular animal body plans originated before or during the Cambrian Explosion.
- Multicellular animals dedicate specialized cells to different tasks.
- The most successful animals are bilaterally symmetrical
- Body cavities have developmental, mechanical and physiological advantages
- Segmentation allows both increased mechanical efficiency and more specialization
- There are two major developmental pathways in animals
Exam III
IV. The most successful animal phyla demonstrate the power of variations on a theme.
The three most successful animal phyla are the molluscs, the arthropods and the vertebrates. The vertebrates have multiple copies of many invertebrate genes. With this additional genetic flexibility, vertebrates exhibit adaptations to life in many environments, and have adapted successfully to life in the water, on land, and as flyers.
- The two most successful protostome body plans are those of arthropods, and molluscs.
- Molluscs demonstrate the evolutionary potential of a regionalized body plan.
- Arthropods demonstrate the adaptability of a segmented body and appendages.
- New genetic criteria separate the living arthropods into three groups: Chelicerates, Myriapods, and Crustacea (which includes both crustaceans and insects).
- Insects are the most successful animal life forms.
- The Deuterostomes include Echinoderms and Chordates.
- Vertebrates are a subphylum of Chordates, and demonstrate the advantages of genetic redundancy.
- Primitive fish show links with primitive chordates
- Bony fish have diversified extensively.
- The tetrapod limb was first seen in aquatic animals.
- Amphibians are limited on land by the demands of skin breathing.
- Reptiles have efficient lungs, watertight skins and amniotic eggs.
- The origin of flight is controversial.
- Birds have adaptations for the energetics and mechanics of flight.
- Both birds and mammals exhibit adaptations for metabolic temperature regulation.
- Hair, skin glands and reproductive adaptations in the mammals.
- Examples of mammalian diversity.
- Humans are primates with special adaptations.
- Genetic and fossil evidence suggests that humans arose in Africa about 200,000 years ago.
Final Exam
Introduction Unit 1 Unit 2 Unit 3 Unit 4