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.