OG

Mader_Essentials_7e_LecturePPT_Ch01_ACCESS

Chapter 1: Biology: The Science of Life

Introduction

  • Learning Changes Everything: Biology is fundamental to understanding life.

  • Essentials of Biology: This chapter covers key concepts related to life, structure, and function.

1.1 The Characteristics of Life

  • Life exhibits diversity but shares common characteristics.

  • Biodiversity Reflects Life: Organisms range from bacteria to plants and animals.

Organization of the Organism

  • Cell: The smallest unit of life; can be unicellular or multicellular.

  • Tissues: Groups of similar cells working together.

  • Organs: Composed of different tissues serving a specific function.

  • Organ Systems: Groups of organs cooperating to perform complex functions.

  • Organism: Complete individual formed from organ systems.

Biological Hierarchy

  • Population: Members of the same species in a specific area.

  • Species: Groups of interbreeding populations.

  • Community: Different species interacting within an area.

  • Ecosystem: Community interactions within their physical environment.

  • Biosphere: The global ecological system integrating all living beings and their relationships.

1.2 Life Requires Materials and Energy

  • Life Sustenance: Life depends on materials (food) and energy sources.

  • Metabolism: The total of all chemical reactions in a cell.

  • Energy Source: The sun is the ultimate energy source for most life forms.

  • Photosynthesis: Converts solar energy into chemical energy, sustaining life.

Energy and Nutrient Flow

  • Energy and nutrients flow through ecosystems, defining their function. Energy does not cycle; it constantly needs to be replenished.

  • Ecosystem Dynamics: Interactions between producers, consumers, and decomposers.

1.3 Living Organisms Maintain Homeostasis

  • Homeostasis: The maintenance of stable internal conditions (temperature, moisture, acidity).

  • Essential for proper functioning and survival.

1.4 Response to Environment

  • Living organisms interact with their environments to find energy and nutrients, often resulting in movement.

1.5 Reproduction and Development

  • All living things reproduce, either by simple division (e.g., bacteria) or through complex processes involving gametes (egg and sperm).

  • Genetic Blueprint: DNA, inherited from parents, guides development.

Adaptations

  • Organisms have adaptations that enhance their survival.

  • Examples: Hawks' specialized hunting skills; humans' ability to live at high elevations.

1.6 Evolution: Core Concept of Biology

  • Evolution: The process where populations adapt over time to their environments.

  • Unity and Diversity of Life: All life traces back to a common ancestor, showing both diversity and similarities.

  • Natural Selection: Proposed by Darwin and Wallace, suggests that organisms better suited to their environments reproduce more successfully.

Evolutionary Processes

  • Darwinian Evolution: Organisms adapt through differential survival and reproductive success.

  • Descent with Modification: Evolutionary changes accumulate across generations.

1.7 Organizing the Diversity of Life

  • Taxonomy: The naming and classification of organisms.

  • Systematics: Classification based on evolutionary relationships.

  • Domains of Life: Three main domains include Archaea, Bacteria (both prokaryotic), and Eukarya (eukaryotic).

Eukaryotic Supergroups

  • Supergroups in Eukarya include:

    • Archaeplastida: Plants and algae.

    • Chromalveolata: Various algae and organisms.

    • Excavata, Rhizaria, Amoebozoa, Opisthokonta: Diverse forms including animals and fungi.

1.8 Binomial Nomenclature

  • Organisms are classified using a two-name system (genus + specific epithet) to avoid confusion.

  • Example: Pisum sativum (garden pea).

1.9 Science: A Way of Knowing

  • Biology involves scientific methods starting from observations leading to hypotheses and experiments.

  • Important to develop hypotheses that can be tested and are based on inductive reasoning.

Scientific Method Overview

  • Formulate predictions and conduct experiments to test hypotheses.

  • Controlled Experiments: Essential for reliable results to infer causation.

  • Publish findings in scientific journals to share and review research.

1.10 Challenges Facing Society

  • Technology: Applied scientific knowledge used for human benefit but brings ethical and environmental challenges.

  • Climate Change: Resulting from imbalance in carbon cycling due to human activity, leading to increased atmospheric CO2 levels.

Biodiversity and Habitat Loss

  • Biodiversity: Refers to the variety of life; many species are threatened by extinction due to human activity.

  • Extinction contributes to loss of ecosystem viability, affecting all living organisms.

Emerging Diseases

  • Emerging & Reemerging Diseases: New and returning diseases pose threats (e.g., COVID-19, Ebola) influenced by global interconnectivity.

  • Understanding biology is key to addressing these challenges.