Biodiversity Overview and Taxonomy

Biodiversity

• Taxonomy: Classifies organisms using a hierarchy (kingdom, phylum, class, order, family, genus, species) and binomial nomenclature (e.g., Homo sapiens)
• Dichotomous Keys: Used to identify organisms based on a series of paired choices
• Phylogenetic Trees/Cladograms: Visual representations of evolutionary relationships among organisms. Interpreting these shows common ancestors and derived traits.
• Viruses: Non-living, require a host cell to replicate; they infect hosts.
• Three Domains: Bacteria (Eubacteria), Archaea, Eukarya. These are the broadest categories of life.
• Prokaryotes vs. Eukaryotes: Prokaryotes lack a nucleus and membrane-bound organelles; Eukaryotes have them. Endosymbiosis describes the evolutionary process of certain prokaryotic cells developing into eukaryotic organelles.
• Six Kingdoms: Bacteria, Archaea, Protista, Fungi, Plantae, Animalia. Each consists of organisms with similar characteristics, notably cells.
• Bacteria: Varying shapes (cocci, bacilli, spirilla), have complex structures, and can reproduce via binary fission
• Reproduction: Diverse methods (binary fission, alternation of generations, and sexual reproduction) exist across different kingdoms based on their characteristics.

Genetics

• Cells: Haploid (single set of chromosomes) vs. diploid (double set of chromosomes).
• Meiosis: A specific type of cell division that results in haploid gametes. Stages involve DNA replication and segregation of chromosomes.
• Karyotypes: Organized displays of chromosomes. Analyzing karyotypes helps identify genetic abnormalities (like nondisjunction), sex determination.
• Mendel's Laws: Law of Segregation (genes segregate during gamete formation) and Independent Assortment (genes on separate chromosomes sort independently).
• Gene Concepts: Dominant/recessive alleles, genotype/phenotype, homozygous/heterozygous
• Inheritance Patterns: Monohybrid/dihybrid crosses, codominance, incomplete dominance
• Pedigrees: Charts tracing the inheritance of traits through generations.
• Inheritance Types: Autosomal (not sex-linked) inheritance, sex-linked inheritance.
• DNA: Structure of DNA, the fundamental unit (nucleotides); complementary base pairing (A-T, C-G).
• Mutations: Permanent changes in DNA sequence.

Evolution

• Evolutionary Thinkers: Darwin, Lamarck, Lyell, Cuvier (proposed theories of evolution and geologic change).
• Evolutionary Concepts: Uniformitarianism, catastrophism, gradualism, punctuated equilibrium (different views on the rate of evolutionary change).
• Natural Selection: Key mechanism of evolution; organisms with advantageous traits are more likely to survive and reproduce.
• Evidence of Evolution: Fossils, homologous structures, vestigial features, and pseudogenes.
• Types of Selection: Artificial selection, sexual selection, stabilizing, directional, disruptive selection.
• Genetic Drift: Change in allele frequencies due to chance events (founder effect, bottleneck effect).
• Speciation: Formation of new species through reproductive isolation mechanisms (allopatric, sympatric).
• Evolutionary Patterns: Divergent/convergent evolution, coevolution, adaptive radiation.

Animal Systems

Digestive System

• Nutrients: Importance and types of carbohydrates, lipids, proteins, vitamins, minerals, and water.
• Digestive Structures: Mouth, pharynx, epiglottis, esophagus, stomach, small intestine, large intestine, rectum, anus, liver, gall bladder, and pancreas—their functions, and locations.
• Digestion Path: Pathway of food through digestive system, enzymes involved in stages, and what happens at each stage.
• Absorption: Mechanisms (diffusion, facilitated diffusion, active transport) involved.
• Comparison: Gastrovascular cavity vs. complete digestive system.

Respiratory System

• Respiratory Structures: Mouth, nose, pharynx, epiglottis, larynx, trachea, bronchi, bronchioles, alveoli, pleural membrane, diaphragm.
• Respiratory Path: Pathway of air through the respiratory system.
• Respiration Mechanics: Muscles involved in breathing, inhalation, exhalation, and negative pressure.
• Comparison: Lungs vs. gills.

Circulatory System

• Heart Structures: Aorta, superior vena cava, inferior vena cava, pulmonary artery, pulmonary vein, right atrium, left atrium, right ventricle, left ventricle, valves (tricuspid, bicuspid, pulmonary, aortic), septum. Locations of all structures and their functions.
• Circulatory Path: Pathway of blood through the heart and body (pulmonary and systemic circuits).
• Vessels: Arteries, capillaries, veins.
• Blood Components: Plasma, red blood cells, white blood cells, platelets.