Overview of Biology

Overview of Biology

• Definition: The scientific study of life and living organisms.
• Branches:
  • Botany (plants)
  • Zoology (animals)
  • Microbiology (microorganisms)
  • Ecology (interactions between organisms and environments)
  • Genetics (heredity and variation)

Cell Biology

• Cell Theory:
  • All living things are composed of cells.
  • Cells are the basic unit of life.
  • All cells arise from pre-existing cells.
• Types of Cells:
  • Prokaryotic (lack nucleus, e.g., bacteria)
  • Eukaryotic (have nucleus, e.g., plants, animals)

Genetics

• DNA Structure:
  • Double helix structure composed of nucleotides (adenine, thymine, cytosine, guanine).
• Gene Expression:
  • Transcription (DNA to mRNA)
  • Translation (mRNA to protein)
• Mendelian Genetics:
  • Dominant and recessive traits.
  • Punnett squares for predicting traits.

Evolution

• Theory of Evolution:
  • Proposed by Charles Darwin.
  • Natural selection drives evolution.
• Speciation:
  • Allopatric (geographic barriers)
  • Sympatric (reproductive barriers)

Ecology

• Ecosystems:
  • Composed of living (biotic) and non-living (abiotic) components.
• Trophic Levels:
  • Producers (plants)
  • Consumers (herbivores, carnivores)
  • Decomposers (fungi, bacteria)

Physiology

• Homeostasis:
  • The process by which organisms maintain a stable internal environment.
• Organ Systems:
  • Circulatory, respiratory, digestive, nervous, musculoskeletal, etc.

Animal Behavior

• Types of Behavior:
  • Innate (genetically programmed)
  • Learned (acquired through experience)
• Social Behavior:
  • Cooperation, competition, altruism.

Plant Biology

• Photosynthesis:
  • Process by which plants convert light energy into chemical energy (glucose).
• Plant Cell Structure:
  • Cell wall, chloroplasts, central vacuole.

Microbiology

• Bacteria:
  • Single-celled organisms, important for processes like nitrogen fixation and decomposition.
• Viruses:
  • Acellular entities that require a host to replicate.

Biochemistry

• Macromolecules:
  • Carbohydrates (energy storage)
  • Proteins (structural, enzymes)
  • Lipids (membranes, energy)
  • Nucleic acids (genetic material)

Biotechnology

• Applications:
  • Genetic engineering, gene therapy, CRISPR technology.
• Methods:
  • Cloning, PCR (polymerase chain reaction), DNA sequencing.

Conservation Biology

• Biodiversity:
  • Importance of species diversity and ecosystem health.
• Threats to Biodiversity:
  • Habitat destruction, pollution, climate change, invasive species.

Overview of Biology

• The scientific study of life and living organisms.
• Branches: Botany, Zoology, Microbiology, Ecology, Genetics

Cell Biology

• Cell Theory: All living things are composed of cells, cells are the basic unit of life, and all cells arise from pre-existing cells.
• Types of Cells: Prokaryotic cells lack a nucleus (e.g., bacteria) while eukaryotic cells have a nucleus (e.g., plants, animals).

Genetics

• DNA Structure: DNA has a double helix structure formed by nucleotides: adenine, thymine, cytosine, and guanine.
• Gene Expression: Transcription (DNA to mRNA) and translation (mRNA to protein) are the key processes in gene expression.
• Mendelian Genetics: Explains inheritance patterns of dominant and recessive traits. It uses Punnett squares to predict the probability of offspring inheriting traits.

Evolution

• Theory of Evolution: Proposed by Charles Darwin, natural selection drives changes in populations over generations.
• Speciation: Process by which new species arise. Allopatric speciation occurs due to geographic barriers, while sympatric speciation occurs due to reproductive barriers.

Ecology

• Ecosystems: Composed of living (biotic) and non-living (abiotic) components.
• Trophic Levels: Include producers (plants), consumers (herbivores, carnivores), and decomposers (fungi, bacteria)

Physiology

• Homeostasis: Organisms maintain a stable internal environment through this process.
• Organ Systems: Circulatory, respiratory, digestive, nervous, musculoskeletal, and others work together to maintain homeostasis.

Animal Behavior

• Types of Behavior: Innate behaviors are genetically programmed, while learned behaviors are acquired through experience.
• Social Behavior: Includes various interactions like cooperation, competition, and altruism.

Plant Biology

• Photosynthesis: The process by which plants convert light energy into chemical energy (glucose).
• Plant Cell Structure: Distinguished by a cell wall, chloroplasts, and a central vacuole.

Microbiology

• Bacteria: Single-celled organisms essential for processes such as nitrogen fixation and decomposition.
• Viruses: Acellular entities that require a host to replicate

Biochemistry

• Macromolecules: Essential for life include carbohydrates (energy storage), proteins (structural, enzymes), lipids (membranes, energy), and nucleic acids (genetic material).

Biotechnology

• Applications: Includes genetic engineering, gene therapy, and CRISPR technology.
• Methods: Techniques used include cloning, PCR (polymerase chain reaction), and DNA sequencing.

Conservation Biology

• Biodiversity: Highlights the importance of species diversity and ecosystem health.
• Threats to Biodiversity: Habitat destruction, pollution, climate change, and invasive species pose a significant threat.