Cell Biology and Genetics Overview

Cell Theory:
- All living organisms are made of cells.
- Cells are the basic unit of life.
- All cells arise from pre-existing cells.
Types of Cells:
- Prokaryotic: No nucleus, smaller, e.g., bacteria.
- Eukaryotic: Nucleus present, larger, e.g., plants, animals.
Cell Organelles:
- Nucleus: Contains genetic material.
- Mitochondria: Powerhouse of the cell, site of ATP production.
- Ribosomes: Protein synthesis.
- Endoplasmic Reticulum (ER):
  - Rough ER: Studded with ribosomes, involved in protein synthesis.
  - Smooth ER: Synthesis of lipids and detoxification.
- Golgi Apparatus: Modifies and packages proteins.
- Lysosomes: Digestion and waste removal.

DNA Structure: Double helix, composed of nucleotides (adenine, thymine, cytosine, guanine).
Gene: Segment of DNA that codes for a protein.
Chromosomes: Structures made of DNA and proteins, humans have 46 chromosomes.
Mendelian Genetics:
- Law of Segregation: Alleles separate during gamete formation.
- Law of Independent Assortment: Genes for different traits are inherited independently.

Natural Selection:
- Mechanism of evolution; organisms better adapted to their environment tend to survive and reproduce.
Adaptation: Traits that enhance survival and reproduction.
Speciation: Formation of new species due to evolutionary processes.

Ecosystem: Interactions between living organisms and their environment.
Biomes: Large ecological areas on the Earth's surface, e.g., forests, deserts.
Food Chain/Web:
- Producers (plants) → Consumers (herbivores, carnivores) → Decomposers (fungi, bacteria).

Body Systems:
- Circulatory System: Transports blood, nutrients, and gases.
- Respiratory System: Gas exchange (O2 in, CO2 out).
- Digestive System: Breaks down food, absorbs nutrients.
- Nervous System: Controls body functions through electrical signals.
Homeostasis: Maintenance of stable internal conditions (temperature, pH, etc.).

Bacteria: Prokaryotic microorganisms, can be beneficial or pathogenic.
Viruses: Acellular, require a host to replicate, cause various diseases.
Fungi: Eukaryotic organisms, decomposers, can be unicellular (yeasts) or multicellular (molds).

Photosynthesis: Process by which plants convert light energy into chemical energy (glucose).
Plant Structure:
- Roots: Absorb water and nutrients.
- Stems: Support and transport.
- Leaves: Site of photosynthesis.
Reproduction:
- Sexual: Involves seeds and pollination.
- Asexual: Cloning through runners, tubers.

Innate Behavior: Instinctive and genetically inherited.
Learned Behavior: Acquired through experience and interaction with the environment.

Macromolecules:
- Carbohydrates: Energy storage and structure (sugars, starches).
- Proteins: Made of amino acids, perform various functions.
- Lipids: Fats and oils, important for membrane structure and energy.
- Nucleic Acids: DNA and RNA, carry genetic information.

All living organisms consist of cells; cells are the fundamental unit of life.
Cells originate from pre-existing cells.
Two primary types of cells exist:
- Prokaryotic cells lack a nucleus and are generally smaller, such as bacteria.
- Eukaryotic cells have a nucleus and are larger, including plant and animal cells.
Key organelles include:
- Nucleus: Houses genetic material (DNA).
- Mitochondria: Responsible for ATP production, often referred to as the powerhouse of the cell.
- Ribosomes: Sites for protein synthesis.
- Endoplasmic Reticulum (ER):
  - Rough ER is associated with ribosomes and protein synthesis.
  - Smooth ER synthesizes lipids and detoxifies harmful substances.
- Golgi Apparatus: Modifies, sorts, and packages proteins for secretion.
- Lysosomes: Contain enzymes for digestion and waste removal.

DNA features a double helix structure composed of four nucleotides: adenine, thymine, cytosine, and guanine.
A gene is a specific segment of DNA coding for proteins.
Chromosomes, made of DNA and proteins, total 46 in humans.
Mendelian Genetics principles include:
- Law of Segregation: Alleles segregate during gamete formation.
- Law of Independent Assortment: Different traits are inherited independently of one another.

Natural Selection is the mechanism of evolution where organisms better adapted to their environment tend to survive and reproduce.
Adaptation refers to traits that improve an organism's chances of survival and reproduction in its environment.
Speciation is the process by which new species arise through evolutionary mechanisms.

An ecosystem comprises interactions between living organisms and their physical environment.
Biomes are distinct ecological areas characterized by specific climates and flora/fauna, including forests and deserts.
The food chain illustrates energy transfer from producers (plants) to consumers (herbivores and carnivores) and finally to decomposers (fungi and bacteria).

Major body systems include:
- Circulatory System: Responsible for transporting blood, nutrients, and gases.
- Respiratory System: Facilitates gas exchange, bringing oxygen in and expelling carbon dioxide.
- Digestive System: Breaks down food and absorbs necessary nutrients.
- Nervous System: Manages body functions via electrical signals.
Homeostasis maintains stable internal conditions, such as temperature and pH balance.

Bacteria are prokaryotic microorganisms that can be beneficial (e.g., gut flora) or pathogenic (causing diseases).
Viruses are acellular entities that need a host to reproduce and can cause various diseases.
Fungi consist of eukaryotic organisms that act as decomposers, existing as unicellular (e.g., yeasts) or multicellular forms (e.g., molds).

Photosynthesis is the method by which plants convert light energy into chemical energy stored as glucose.
Plant structures include:
- Roots: Absorb water and minerals from the soil.
- Stems: Provide support and transport nutrients and water.
- Leaves: Main site of photosynthesis.
Plant reproduction occurs either sexually, involving seeds and pollination, or asexually through structures like runners and tubers.

Innate Behavior is instinctual and inherited genetically, not learned or influenced by the environment.
Learned Behavior develops through experience and interaction with the surroundings, often involving conditioning.

Macromolecules include:
- Carbohydrates: Serve as energy sources and structural components (e.g., sugars, starches).
- Proteins: Composed of amino acids, serving diverse functions in the body.
- Lipids: Fats and oils critical for membrane formation and energy storage.
- Nucleic Acids: DNA and RNA are responsible for carrying and transmitting genetic information.

Gene Editing techniques, such as CRISPR, allow for precise alterations of DNA sequences.
Cloning produces genetically identical copies of organisms.
Biopharmaceuticals are drugs developed using biotechnological processes, often derived from biological products.