Basics of Biology and Genetics

Basics of Biology

• Definition: Study of life and living organisms.
• Branches:
  • Botany: Study of plants.
  • Zoology: Study of animals.
  • Microbiology: Study of microorganisms.
  • Genetics: Study of heredity and variation.

Cell Biology

• Cell Theory: All living organisms are composed of cells; cells are the basic unit of life; all cells arise from pre-existing cells.
• Types of Cells:
  • Prokaryotic: Simple, no nucleus; e.g., bacteria.
  • Eukaryotic: Complex, with a nucleus; e.g., plant and animal cells.
• Cell Organelles:
  • Nucleus: Contains genetic material (DNA).
  • Mitochondria: Powerhouse of the cell (energy production).
  • Chloroplasts: Site of photosynthesis in plant cells.

Genetics

• DNA Structure: Double helix composed of nucleotides (A, T, C, G).
• Gene: Segment of DNA that codes for a protein.
• Chromosomes: Structures made of DNA and protein; humans have 46 chromosomes.
• Mendelian Inheritance: Principles of segregation and independent assortment.

Evolution

• Natural Selection: Process where organisms better adapted to their environment tend to survive and reproduce.
• Adaptation: Traits that enhance survival and reproduction in a specific environment.
• Common Descent: All species share a common ancestor.

Ecology

• Ecosystem: A community of living organisms interacting with their environment.
• Biomes: Large geographical biotic communities; e.g., forests, deserts.
• Food Chains/Webs: Represent the flow of energy and nutrients through trophic levels.

Human Biology

• Organ Systems:
  • Circulatory: Transports blood and nutrients.
  • Respiratory: Facilitates gas exchange.
  • Digestive: Breaks down food for energy.
  • Nervous: Controls body functions via signaling.
• Homeostasis: Maintenance of stable internal conditions despite external changes.

Plant Biology

• Photosynthesis: Process by which green plants convert sunlight into chemical energy (glucose).
• Plant Structures:
  • Root: Anchors plant, absorbs water and nutrients.
  • Stem: Supports plant, transports nutrients.
  • Leaves: Main site of photosynthesis.

Microbiology

• Bacteria: Prokaryotic microorganisms, can be beneficial or pathogenic.
• Viruses: Non-cellular entities requiring a host to replicate.
• Fungi: Eukaryotic organisms, some are decomposers important for nutrient cycling.

Biotechnology

• Genetic Engineering: Manipulation of an organism's DNA to achieve desired traits.
• CRISPR: A technology for editing genes with precision.
• Applications: Medicine, agriculture, environmental management.

Important Concepts

• Homeostasis: Process of maintaining a stable internal environment.
• Photosynthesis vs. Cellular Respiration:
  • Photosynthesis: Converts CO2 and H2O into glucose and O2 using sunlight.
  • Cellular Respiration: Converts glucose and O2 into CO2 and H2O, releasing energy.
• Trophic Levels:
  • Producers (autotrophs)
  • Primary consumers (herbivores)
  • Secondary consumers (carnivores)
  • Tertiary consumers

Research Methods

• Observation: Gathering data through direct observation.
• Hypothesis Testing: Making predictions that can be tested through experiments.
• Data Analysis: Interpreting results to draw conclusions.