Cell Biology and Genetics Overview

Cell Biology

• 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.

Genetics

• 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.

Evolution

• 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).

Ecology

• 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.

Human Biology

• 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).

Microbiology

• 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.

Biochemistry

• 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.

Physiology

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

Biotechnology

• 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 Biology

• 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.

Genetics

• 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.

Evolution

• 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.

Ecology

• 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.

Human Biology

• 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.

Microbiology

• 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.

Biochemistry

• 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.

Physiology

• 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).

Biotechnology

• 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.

This quiz covers fundamental concepts of cell biology and genetics, including cell theory, types of cells, and the structure of DNA. Learn about cell organelles like the nucleus and mitochondria, as well as basic genetic principles such as Mendelian inheritance. Test your knowledge on these essential topics in life sciences.