Cell Biology and Genetics Overview

Cell Biology

• Cell Structure: Basic unit of life; includes prokaryotic (no nucleus) and eukaryotic (nucleus present) cells.
• Organelles:
  • Nucleus: Contains DNA, controls cell activities.
  • Mitochondria: Powerhouse of the cell, energy production (ATP).
  • Ribosomes: Protein synthesis.
  • Endoplasmic Reticulum (ER): Rough ER (with ribosomes) synthesizes proteins; Smooth ER synthesizes lipids.
  • Golgi Apparatus: Modifies, sorts, and packages proteins.
  • Lysosomes: Digestive enzymes for waste breakdown.

Genetics

• DNA Structure: Double helix composed of nucleotides (adenine, thymine, cytosine, guanine).
• Gene Expression: Process from DNA to RNA (transcription) and RNA to protein (translation).
• Mendelian Genetics: Law of Segregation, Law of Independent Assortment; dominant and recessive traits.
• Chromosomes: Humans have 23 pairs; sex chromosomes determine gender (XX or XY).

Evolution

• Natural Selection: Mechanism of evolution; organisms better adapted to their environment tend to survive and produce offspring.
• Speciation: Formation of new species through isolation, genetic drift, and adaptation.
• Evidence of Evolution: Fossil records, comparative anatomy, molecular biology.

Ecology

• Ecosystems: Community of living organisms and their physical environment interacting as a system.
• Biomes: Large ecological areas (e.g., forests, deserts) characterized by specific climate and vegetation.
• Food Chains and Webs: Energy flow through producers (plants), consumers (animals), and decomposers (fungi/bacteria).
• Population Dynamics: Study of populations, including growth rates, carrying capacity, and factors affecting population size.

Physiology

• Homeostasis: Maintenance of stable internal conditions (e.g., temperature, pH).
• Organ Systems:
  • Circulatory: Transports blood and nutrients.
  • Respiratory: Gas exchange (oxygen and carbon dioxide).
  • Digestive: Breaks down food and absorbs nutrients.
  • Nervous: Controls body functions through signals.

Biochemistry

• Macromolecules:
  • Proteins: Made of amino acids, perform various functions (enzymes, structure).
  • Carbohydrates: Sugars and starches, energy sources.
  • Lipids: Fats and oils, energy storage and cell membranes.
  • Nucleic Acids: DNA and RNA, genetic information storage and transfer.

Microbiology

• Bacteria: Prokaryotic microorganisms; roles in decomposition, fermentation, and disease.
• Viruses: Non-cellular entities that require a host to replicate.
• Fungi: Eukaryotic organisms; decomposers and some are pathogenic.

Plant Biology

• Photosynthesis: Process by which plants convert light energy into chemical energy (glucose).
• Plant Structure: Roots (absorb water/nutrients), stems (support), leaves (photosynthesis).

Animal Behavior

• Innate vs. Learned Behaviors: Innate behaviors are genetic; learned behaviors are acquired through experience.
• Social Structures: Group dynamics in species (e.g., packs, herds).
• Communication: Methods animals use to convey information (vocalizations, body language).

Cell Biology

• Cells are the basic unit of life, categorized into prokaryotic (lack nucleus) and eukaryotic (contain nucleus) types.
• The nucleus houses DNA and regulates cellular activities.
• Mitochondria generate ATP, serving as the cell's energy currency.
• Ribosomes are essential for synthesizing proteins.
• The endoplasmic reticulum has two forms: Rough ER, which is ribosome-studded and synthesizes proteins, and Smooth ER, which synthesizes lipids.
• The Golgi apparatus modifies, sorts, and packages proteins for transport.
• Lysosomes contain digestive enzymes important for breaking down waste materials.

Genetics

• DNA is structured as a double helix composed of nucleotides: adenine, thymine, cytosine, and guanine.
• Gene expression involves transcription (DNA to RNA) and translation (RNA to protein).
• Mendelian genetics focuses on inheritance patterns, including the Law of Segregation and the Law of Independent Assortment; it distinguishes between dominant and recessive traits.
• Humans possess 23 pairs of chromosomes, with sex chromosomes (XX for females, XY for males) determining gender.

Evolution

• Natural selection is a fundamental mechanism of evolution, whereby organisms best suited to their environment are more likely to survive and reproduce.
• Speciation occurs when new species emerge due to factors like isolation, genetic drift, and adaptation to different environments.
• Evidence supporting evolution can be found in fossil records, comparative anatomical structures, and advancements in molecular biology.

Ecology

• Ecosystems comprise communities of living organisms along with their physical environments, functioning interactively.
• Biomes are large ecological regions, such as forests and deserts, identified by their climate and predominant vegetation types.
• Food chains and webs illustrate energy transfer, starting with producers (plants), through consumers (animals), and ending with decomposers (fungi and bacteria).
• Population dynamics examines changes in population sizes, growth rates, and carrying capacities influenced by various environmental factors.

Physiology

• Homeostasis is the process through which organisms maintain stable internal conditions, such as temperature and pH levels.
• Major organ systems include:
  • Circulatory: Responsible for blood and nutrient transport.
  • Respiratory: Facilitates gas exchange of oxygen and carbon dioxide.
  • Digestive: Breaks down food for nutrient absorption.
  • Nervous: Coordinates body functions through signaling.

Biochemistry

• Macromolecules consist of:
  • Proteins: Composed of amino acids, performing diverse roles including enzymatic and structural functions.
  • Carbohydrates: Sugars and starches that serve as primary energy sources.
  • Lipids: Include fats and oils for energy storage and forming cell membranes.
  • Nucleic acids: DNA and RNA, responsible for the storage and transfer of genetic information.

Microbiology

• Bacteria are prokaryotic microorganisms contributing to decomposition, fermentation, and occasionally disease.
• Viruses are non-cellular entities that must infect a host to replicate.
• Fungi are eukaryotic organisms that act as decomposers, with some species being pathogenic.

Plant Biology

• Photosynthesis enables plants to convert light energy into chemical energy stored as glucose.
• Plant structures include:
  • Roots: Function in water and nutrient absorption.
  • Stems: Provide structural support.
  • Leaves: Main site of photosynthesis.

Animal Behavior

• Innate behaviors are genetically inherited, while learned behaviors develop through experience.
• Social structures determine group dynamics within species, as seen in packs or herds.
• Communication in animals involves vocalizations and body language to convey information.