Fundamental Properties and Organization of Life

Fundamental Properties of Life

• Life is characterized by properties differentiating living organisms from non-living matter.
• All living organisms share specific properties.
• Cellular Organization: Organisms are composed of one or more cells, exhibiting a complexity hierarchy.
• Growth and Development: Organisms increase in size and complexity over time, like seed germination or human growth.
• Reproduction: Organisms produce new individuals through sexual or asexual means.
• Response to Stimuli: Organisms react to environmental changes, such as plants bending toward light or animals' fight-or-flight response.
• Homeostasis: Organisms maintain a stable internal environment via temperature regulation and pH balance.
• Metabolism: Chemical reactions maintain life, including photosynthesis and cellular respiration.
• Evolution: Heritable trait changes in populations over generations enable adaptation and biodiversity.

Organization of Life

• Life's organization follows a hierarchical structure.
• Organelles are specialized structures within cells, like the nucleus and mitochondria, essential for cell survival.
• Cells, the fundamental units of life, are formed by organelles, e.g., human blood cells.
• Tissues are groups of similar cells, such as human skin tissue.
• Organs and organ systems are formed by tissues, e.g., the stomach and intestine.
• Organisms are individual living entities.
• Populations are groups of the same species, like pine trees in a forest.
• Communities include all plant and animal species interacting in a given area.
• Ecosystems encompass communities and their physical environments, such as coastal ecosystems.
• Biosphere includes all ecosystems on Earth, integrating every living organism and their interactions globally.

Cell Structure and Function

• Cells serve as the basic units of life.
• Cells are categorized into prokaryotic and eukaryotic types.
• All cells possess a plasma membrane, cytoplasm, DNA, and ribosomes.
• Prokaryotic cells, such as bacteria, are simpler, with a cell wall and no nucleus.
• Prokaryotes lack membrane-bound organelles; some have flagella or pili.
• Eukaryotic cells, found in plants, animals, fungi, and protists, are more complex.
• Eukaryotic cells contain a nucleus and organelles.
• The nucleus houses genetic material and controls cellular activities.
• Mitochondria produce energy.
• Chloroplasts in photosynthetic cells facilitate photosynthesis.
• The endoplasmic reticulum and Golgi apparatus synthesize and transport proteins and lipids.
• Understanding cell composition is essential for understanding how organisms grow, develop, and maintain homeostasis.

Evolution and Adaptation

• Evolution is the change in populations of organisms over time via genetic makeup variations.
• Mechanisms driving this process: natural selection, genetic drift, and mutation.
• Natural selection favors individuals with traits more likely to survive and reproduce.
• Peppered moths in England exemplify natural selection.
• Darker moths became more common during the Industrial Revolution due to camouflage against soot-darkened trees.
• Natural selection acts on existing variation within a population.
• Sexual reproduction involves two parents combining genetic material.
• Offspring have unique genetic combinations leading to trait differences.
• Genetic variation is crucial for natural selection, providing traits for selection.
• Sexual reproduction significantly contributes to life's diversity.
• Sexual reproduction enables adaptation to changing environments
• Selective pressures shift, favoring different adaptations over time.
• Dynamic trait changes ensure long-term species survival.

Taxonomic Classification

• A method to organize and name organisms based on shared characteristics.
• Taxonomic classification groups species into broader levels such as species, genus, family, order, class, phylum, kingdom, and domain.
• Traditional taxonomic classification categorizes based on observable traits.
• Modern biology uses phylogenetic trees to show evolutionary relationships among species.

Phylogenetic Tree

• Represents evolutionary relationships among biological species based on genetic and physical characteristics.
• Branch points/nodes denote a common ancestor.
• Trees can be rooted or unrooted.
• Rooted trees have a single ancestral lineage.
• Unrooted trees show relationships without implying a common ancestor.
• Construction involves analyzing trait/genetic sequence similarities and differences.
• This analysis aids in tracing the evolutionary history of organisms.
• Phylogenetic trees show speciation events contributing to biodiversity and distinct biological lineages.

Speciation

• A species is typically defined as a group of organisms capable of interbreeding.
• Speciation, the process by which new species arise, often occurs when populations become reproductively isolated from each other
• Speciation leads to genetic divergence over time.

Microscopy and Cell Observation Lab

• Review microscope parts and calculate total magnification using: Total Magnification = (Magnification of objective lens) * (magnification of eyepiece)
• Practice microscopy skills using letter "e" and multicolor thread slides.
• Observe permanent slides of bacteria and human cheek cells.
• Prepare and observe wet mounts of diatomaceous earth under the microscope and record microscopic images.

Phylogenetic Tree Lab

• This lab activity uses Pipe Cleaners.
• First, start by gathering five pipe cleaners of different colors per group (e.g., pink, purple, green, blue, orange).
• Second, collect the five pipe cleaners together so that they are flush at one end, then twist them together at one end, using about 2 inches of the bundle.
• Third, take the other end of the pink pipe cleaner and wrap it around the others once. Twist the remaining pipe cleaners together for another 1.5 to 2 inches.
• Fourth, repeat this step with the remaining pipe cleaners (purple, green, blue, orange) until all are isolated in this order: pink, purple, green, blue, orange.
• Fifth, bend the pipe cleaners 90° at each point of intersection and another 90° at each halfway point to create a branching structure.
• Sixth, manipulate the tree by rotating branches to see how it changes the appearance but not the relationships.
• Seventh, use the different colors to identify and trace complete lineages within the tree.
• Constructing a phylogenetic tree using pipe cleaners can help understand evolutionary relationships and tree-thinking concepts.

Microscope Parts and Functions

• Eyepiece (Ocular Lens): Look through this lens at the top (usually 10x or 15x power).
• Objective Lenses: These typically range from 4x to 100x magnification.
• Rotating Nosepiece: Most microscopes have multiple objective lenses on a rotating nosepiece.
• Stage: Flat platform where slides are placed.
• Stage Clips: Clips hold the slides in place on the stage.
• Revolving Nosepiece (Turret): Holds two or more objective lenses and easily changes power.
• Coarse Adjustment Knob: Brings the specimen into general focus.
• Fine Adjustment Knob: Fine-tunes the focus and increases detail.
• Diaphragm (Iris): Located under the stage, adjust the intensity of light.
• Light Source (Illuminator): Provides light via mirror or electric light.
• Condenser: Focuses light onto the specimen and is located below the stage.
• Arm: Supports the tube and connects it to the base and is used to carry the microscope.
• Base: The bottom of the microscope is used for support.
• Head (Body Tube): Connects the eyepiece to the objective lenses.

Explore the fundamental properties that define life, including cellular organization, growth, reproduction, response to stimuli, homeostasis, metabolism and evolution. Understand how these properties differentiate living organisms from non-living matter. Learn about the hierarchical levels of biological organization, from molecules to the biosphere, and the emergent properties at each level.