3.7 bio

In Unit One, students explored essential concepts in organism classification, focusing on: - Distichs: The arrangement of elements in biological classification. - Nodes: Points of divergence in a phylogenetic tree, representing common ancestors. - Clades: Groups of organisms that include an ancestor and all of its descendants.
Unit Three revisits the concept of domains but emphasizes a different approach.
Three Domains of Life: - Bacteria (or Eubacteria): Single-celled organisms with prokaryotic cells, lacking a true nucleus. - Archaea: Similar to bacteria but distinct in genetic and biochemical characteristics; they often survive in extreme environments. - Eukarya: Organisms with eukaryotic cells that have a defined nucleus. This group includes all fungi, plants, and animals.

The domains are further divided into kingdoms, phyla, classes, orders, families, genera, and species. - This classification is essential for understanding the interrelations among various organisms. - The system was developed by Carl Linnaeus, known for binomial nomenclature.

Creation of Species: Occurs over a timeline, visualized as evolving from left (earliest) to right (most recent).
Phylogenetic Tree: - A diagram used to illustrate the evolutionary relationships between different species. - Nodes on the tree represent common ancestors between groups. - Branching indicates the divergence of species. - The tree can include data from: - Morphological features (physical forms and structures) - DNA sequences - Fossil records - Behavioral characteristics

Organisms are often grouped based on homologous features, which are traits inherited from a common ancestor.
The concept of acquired characteristics (traits developed in an organism's lifetime) does not apply in evolutionary theory, according to Lamarck's ideas that have since been discounted.

The root of the tree is the starting point, representing the most distant ancestors.
Movement upward in a tree corresponds to more recent species.
Nodes indicate common ancestors.
Clade: A group that includes an ancestor and all its descendants: - To denote a clade, circle the node representing the common ancestor. - Example: For species B and C, their clade includes the common ancestor (node A).

Late appearance on a phylogenetic tree does not imply higher complexity or advancement: - Example: Bacteria are not less complex than humans or birds, highlighting that evolution does not follow a ladder-like progression.

New World vs. Old World Monkeys: - New World Monkeys: Found in tropical regions of the Americas; characterized by flat noses and side-facing nostrils. - Old World Monkeys: Native to Africa, Southern Europe, and Asia, inclusive of species like macaques and baboons.

Reference to COVID-19 in March 2020 illustrates the transfer of pathogens from animals to humans, affecting evolutionary timelines.

Mycobacterium tuberculosis: Bacterial strain that developed antibiotic resistance when subjected to antibiotic treatment. - Importance of understanding mutations: - A point mutation can occur where a single base pair in DNA is changed, potentially leading to drug resistance.
Consequences of Antibiotic Treatment: - Importance of completing antibiotic courses; stopping prematurely can allow survival of resistant bacterial strains.

Consideration for future studies includes looking into genomic sequences and developing a more nuanced understanding of evolutionary relationships.
Students will engage with practical exercises (e.g., Gizmo) to solidify understanding of the concepts discussed in class.