Cell Biology and Genetics Overview

Cell Theory: All living organisms are composed of cells; the cell is the basic unit of life; all cells arise from pre-existing cells.
Types of Cells:
- Prokaryotic: No nucleus, smaller, simpler (e.g., bacteria).
- Eukaryotic: Nucleus present, larger, complex (e.g., plants, animals, fungi).
Cell Organelles:
- Nucleus: Contains genetic material.
- Mitochondria: Powerhouse of the cell, energy production.
- Ribosomes: Protein synthesis.
- Endoplasmic Reticulum (ER):
  - Rough ER: Studded with ribosomes, synthesizes proteins.
  - Smooth ER: Lipid synthesis, detoxification.
- Golgi Apparatus: Modifies, sorts, and packages proteins.

DNA Structure: Double helix, made of nucleotides (adenine, thymine, cytosine, guanine).
Gene: Segment of DNA that codes for a protein.
Alleles: Different versions of a gene.
Mendelian Inheritance:
- Dominant and recessive traits.
- Law of Segregation: Alleles separate during gamete formation.
- Law of Independent Assortment: Genes for different traits segregate independently.

Natural Selection: Process where organisms better adapted to their environment tend to survive and produce more offspring.
Speciation: Formation of new and distinct species.
Evidence for Evolution:
- Fossil record.
- Comparative anatomy (homologous and analogous structures).
- Molecular biology (DNA comparisons).

Ecosystems: Community of living organisms interacting with their environment.
Biomes: Large geographic biotic communities (e.g., rainforest, desert).
Food Chains and Webs:
- Producers (autotrophs) convert sunlight into energy.
- Consumers (heterotrophs) feed on producers.
- Decomposers recycle nutrients back into the ecosystem.

Organ Systems:
- Nervous System: Controls and coordinates body activities.
- Circulatory System: Transports nutrients and oxygen.
- Respiratory System: Facilitates gas exchange.
- Digestive System: Breaks down food for nutrient absorption.
Homeostasis: Maintenance of stable internal conditions (e.g., temperature regulation).

Types of Microorganisms:
- Bacteria: Prokaryotic, can be beneficial or pathogenic.
- Viruses: Non-living, require a host to reproduce.
- Fungi: Eukaryotic, decomposers, some are pathogens.
- Protists: Diverse group, can be unicellular or multicellular.

Macromolecules:
- Proteins: Made of amino acids, essential for structure and function.
- Carbohydrates: Provide energy, made of sugars.
- Lipids: Fats and oils, important for membranes and energy storage.
- Nucleic Acids: DNA and RNA, responsible for genetic information.

Homeostasis Mechanisms: Feedback systems (negative and positive) that regulate body functions.
Metabolism: All chemical reactions in the body; includes catabolism (breakdown) and anabolism (synthesis).

Genetic Engineering: Manipulation of an organism's genetic material.
CRISPR: A tool for editing genes, allowing for precise alterations.
Bioremediation: Use of organisms to remove or neutralize contaminants from soil and water.

Cell Theory: Foundation of biology stating all living organisms consist of cells, which are the fundamental unit of life, and all cells arise from existing cells.
Types of Cells:
- Prokaryotic Cells: Lack a nucleus, generally smaller and simpler in structure (e.g., bacteria).
- Eukaryotic Cells: Have a defined nucleus, larger and more complex (e.g., plants, animals, fungi).
Cell Organelles:
- Nucleus: Stores genetic material (DNA).
- Mitochondria: Known as the powerhouse of the cell; responsible for ATP (energy) production.
- Ribosomes: Site of protein synthesis, found free-floating or on the rough ER.
- Endoplasmic Reticulum (ER):
  - Rough ER: Contains ribosomes; involved in protein synthesis.
  - Smooth ER: Lacks ribosomes; involved in lipid synthesis and detoxification processes.
- Golgi Apparatus: Modifies, sorts, and packages proteins for secretion or use within the cell.

DNA Structure: Composed of a double helix formed by nucleotides, which include adenine, thymine, cytosine, and guanine.
Gene: A specific sequence of DNA that codes for a protein, determining inherited traits.
Alleles: Different variants of a gene that can lead to variations in traits.
Mendelian Inheritance:
- Dominant traits mask recessive traits.
- Law of Segregation: Inheritance of alleles occurs when gametes are formed.
- Law of Independent Assortment: Genes for different traits are inherited independently.

Natural Selection: The process by which organisms better adapted to their environment have a greater chance of survival and reproduction.
Speciation: The evolutionary process leading to the formation of new and distinct species.
Evidence for Evolution:
- Fossil Record: Shows progressive changes in species over time.
- Comparative Anatomy: Analyzes homologous (similar structures from common ancestry) and analogous (similar functions, different ancestry) structures.
- Molecular Biology: Compares DNA sequences among different organisms.

Ecosystems: Interactions between living organisms and their physical environment.
Biomes: Large ecological areas with distinct climates and communities, such as rainforests and deserts.
Food Chains and Webs:
- Producers: Autotrophs that convert sunlight into energy (e.g., plants).
- Consumers: Organisms that obtain energy by consuming others (e.g., herbivores and carnivores).
- Decomposers: Organisms that break down dead matter, returning nutrients to the ecosystem.

Organ Systems:
- Nervous System: Coordinates and controls bodily functions and responses.
- Circulatory System: Transports essential nutrients and oxygen throughout the body.
- Respiratory System: Exchanges gases, facilitating uptake of oxygen and release of carbon dioxide.
- Digestive System: Breaks down food substances for nutrient absorption.
Homeostasis: The process of maintaining stable internal conditions, vital for optimal functioning, including temperature regulation.

Types of Microorganisms:
- Bacteria: Prokaryotic organisms that can have beneficial or harmful effects on humans and ecosystems.
- Viruses: Non-cellular particles that require a host cell to replicate and survive.
- Fungi: Eukaryotic organisms that decompose organic material, some of which can be pathogenic.
- Protists: A diverse group of eukaryotic organisms that can be unicellular or multicellular.

Macromolecules: Essential biological molecules include:
- Proteins: Composed of amino acids, crucial for structure, function, and regulation of the body.
- Carbohydrates: Serve as a primary energy source, composed of sugar units.
- Lipids: Include fats and oils, important for cellular membranes and energy storage.
- Nucleic Acids: DNA and RNA, which store and transmit genetic information.

Homeostasis Mechanisms: Utilize feedback systems (both negative and positive) to regulate bodily functions and maintain balance.
Metabolism: Encompasses all biochemical reactions, including catabolism (breakdown of molecules) and anabolism (building of molecules).

Genetic Engineering: The manipulation of an organism’s genetic material to achieve desired traits or outcomes.
CRISPR: A revolutionary gene-editing tool that allows specific alterations to DNA sequences.
Bioremediation: The use of living organisms to eliminate or neutralize contaminants in environmental settings, such as soil and water.