biodiversity

DNA - The Blueprint of Life

  • DNA is referred to as the wonder molecule and serves as the blueprint for life.

Cell Organization

Simple Cells

  • Early cells were simple with minimal development.

  • They contained basic forms of DNA as genetic material.

  • Some developed organelles for processes such as locomotion, feeding, and breathing.

Developmental Progression

  • As cells evolved, their genetic material became enclosed within a protective cover, forming the nucleus.

Structure of Well-Developed Cells

  • Advanced cell types include organelles such as:

    • Mitochondria

    • Ribosomes

    • Chloroplasts

    • Nucleus

    • Endoplasmic Reticulum

    • Golgi Body

Cell Functions

Single Cell Functions

  • Even single cells exhibit various functions, including a visible eating process, depicted under a microscope at 100 μm.

Cellular Organization

  • Cells are defined as compartments that perform various tasks and maintain internal order.

  • Cells collectively form tissues, which in turn create organs and organ systems, culminating in a complete organism.

Homeostasis

  • Homeostasis refers to maintaining a constant internal environment within a living organism.

    • Key factors include temperature, pressure, pH, and fluid consistency.

    • This maintenance requires energy derived from metabolism.

    • For instance, excess heat is expelled as sweat to regulate body temperature.

    • Not all substances affect the body adversely, such as homemade drinks with varying pH levels.

Growth

Development Stages in Life Cycle

  • Stages of tadpole development include:

    • Day 1: Egg

    • Day 3-4: Tailbud

    • Day 6: Tadpole with external gills

    • Day 9: Tadpole with internal gills

    • Day 12: Tadpole with operculum

    • Day 70: Tadpole with hind limbs

    • Day 84: Tadpole with forelimbs

    • Beyond Day 84: Metamorphosis to young frog

Cellular Growth

  • Mature cells divide to form new daughter cells, contributing to an increase in mass and size.

  • Development begins in the womb, comprising rapid differentiation and organogenesis.

Energy Utilization

Energy Flow in Ecosystems

  • Plants capture sunlight, absorb water, minerals, and gases to create food via photosynthesis.

  • Animals obtain energy by consuming plant-based food.

Cellular Energy Needs

  • In animals, food is metabolized at the cellular level to release energy essential for cell maintenance and overall organism functionality.

  • This energy is stored in ATP (Adenosine Triphosphate) molecules.

Response to Surroundings

Sensory Feedback

  • Organisms perceive stimuli via sensory organs, leading to appropriate responses.

  • This ability to detect environmental changes is crucial for survival and adaptation.

  • Adaptations that enhance survival capabilities are often passed down to subsequent generations, as outlined in Charles Darwin's "Origin of Species."

Example of Adaptation

  • Ancestor Finch: Various adaptive traits include insect-eating and seed-eating beaks.

  • Different beak structures depict natural selection processes.

Reproduction and Heredity

DNA in Reproduction

  • DNA (Deoxyribonucleic Acid) serves as the blueprint for organisms, ensuring genetic consistency within species.

  • Some organisms reproduce asexually using body parts (e.g., sugarcane, potato) while others involve complex reproductive systems (flowing plants and animals).

Biodiversity Overview

Definitions

  • Biodiversity encompasses the variety of life in a given ecosystem.

  • Biological communities consist of all different species populations interacting in one systemic habitat.

Population and Organism Concepts

  • A population includes all members of a species residing in a community.

  • Organisms are individual living entities composed of organ systems and organs with specific functions.

  • Cells represent the fundamental unit of life, exhibiting essential characteristics of living organisms.

Taxonomy

Historical Perspective

  • Aristotle proposed that life could emerge from non-living matter, initiating discussions about taxonomy.

  • Taxonomy classifies species based on their relationships.

Classification System

  • Multiple categories based on organism characteristics:

    • Plants: Photosynthesize.

    • Animals: Ingest and absorb.

    • Fungi: Absorb nutrients.

  • Domains of life include Archea and Bacteria (prokaryotes) and Eukarya (eukaryotic organisms).

Domains of Life

Domain Archea

  • Encompasses ancient prokaryotes, capable of surviving extreme conditions, e.g., sulfur-rich environments.

Domain Bacteria

  • Comprises most known prokaryotes, some of which can cause infections.

Domain Eukarya

  • Encompasses all eukaryotes with complex cells having membranes, nuclei, and organelles, including kingdoms such as:

    • Fungi

    • Plantae

    • Animalia, among others.