Cell Structure Quiz

Basic Units of Life
- Cells are the fundamental building blocks of all living organisms.
- Two main types of cells: prokaryotic (without nucleus) and eukaryotic (with nucleus).
Prokaryotic Cells
- Lack membrane-bound organelles.
- Example: Bacteria and Archaea.
- Structure includes:
  - Plasma membrane
  - Cytoplasm
  - Ribosomes
  - Genetic material (circular DNA)
Eukaryotic Cells
- Contain membrane-bound organelles.
- Examples: Animal cells, plant cells, fungi, and protists.
- Key organelles include:
  - Nucleus: houses genetic material.
  - Mitochondria: energy production (ATP).
  - Endoplasmic reticulum: synthesis of proteins and lipids.
  - Golgi apparatus: modification and packaging of proteins.
  - Lysosomes: digestion and waste removal.
  - Cell wall (in plants): structural support and protection.
Cell Membrane
- Composed of a phospholipid bilayer with embedded proteins.
- Functions: regulates entry and exit of substances, communication, and cell signaling.
Cytoskeleton
- Network of protein filaments and tubules.
- Provides structural support, aids in cell movement, and organizes organelles.

Basic Principles of Evolution
- Evolution is the change in the heritable characteristics of biological populations over successive generations.
- Driven by mechanisms such as natural selection, mutation, gene flow, and genetic drift.
Evidence for Evolution
- Fossil records: show transitional forms and changes over time.
- Comparative anatomy: similarities in structure among different species indicate common ancestry (homologous structures).
- Molecular biology: genetic similarities among species provide insights into evolutionary relationships.
Evolutionary Developmental Biology (Evo-Devo)
- Examines the relationship between ontogeny (development) and phylogeny (evolution).
- Focuses on how changes in developmental processes lead to evolutionary changes.

Cells are the basic units of life, classified as prokaryotic or eukaryotic.
Prokaryotic Cells
- Do not have membrane-bound organelles.
- Examples include bacteria and archaea.
- Composed of a plasma membrane, cytoplasm, ribosomes, and circular DNA as genetic material.
Eukaryotic Cells
- Feature membrane-bound organelles.
- Include animal cells, plant cells, fungi, and protists.
- Key organelles consist of:
  - Nucleus, which stores genetic material.
  - Mitochondria, responsible for ATP production.
  - Endoplasmic reticulum for protein and lipid synthesis.
  - Golgi apparatus for protein modification and packaging.
  - Lysosomes for digestion and waste removal.
  - Cell wall (found in plants) for structural support and protection.
Cell Membrane
- Made up of a phospholipid bilayer with embedded proteins.
- Functions include regulating substance entry and exit, communication, and signaling.
Cytoskeleton
- A network of protein filaments and tubules that provides structural support, aids in movement, and organizes organelles.

Evolution entails changes in heritable traits of biological populations across generations.
Natural Selection
- Mechanism by which advantageous traits that improve fitness lead to better survival and reproduction.
- Key factors involve:
  - Variation in traits among individuals.
  - Inheritance of traits from parents.
  - Differential survival and reproductive success based on these traits.
Speciation
- The formation of new species through evolutionary processes.
- Types include:
  - Allopatric speciation, occurring due to geographic separation.
  - Sympatric speciation, arising from reproductive isolation within the same location.
Evidence for Evolution
- Fossil records indicate transitional forms and evolutionary changes.
- Comparative anatomy highlights homologous structures that suggest common ancestry.
- Molecular biology examines genetic similarities to elucidate evolutionary connections.
Phylogenetics
- Investigates evolutionary relationships among biological entities using cladograms and phylogenetic trees to illustrate these pathways.
Evolutionary Developmental Biology (Evo-Devo)
- Explores the connection between developmental processes (ontogeny) and evolutionary changes (phylogeny).
- Focuses on how developmental changes can lead to evolutionary shifts.

Biomolecules include four main categories:
- Carbohydrates: Serve as energy sources and structural components; examples include sugars and starches.
- Proteins: Composed of amino acids; essential for enzymes, structural roles, and transport functions.
- Lipids: Consist of fatty acids and glycerol; crucial for energy storage and forming cell membranes.
- Nucleic Acids: DNA and RNA function in storing and transferring genetic information.
Cell Membrane:
- Comprised of a phospholipid bilayer with embedded proteins.
- Functions as a selectively permeable barrier, facilitating communication and transport of substances.
Water:
- Acts as a solvent for biochemical reactions, regulates temperature, and is involved in metabolic processes.

Prokaryotic Cells:
- Do not possess a nucleus; DNA is circular and found in the nucleoid region.
- Contain ribosomes, a cell wall made of peptidoglycan, and a plasma membrane, with some having flagella for movement.
Eukaryotic Cells:
- Have a nucleus which contains linear DNA organized into chromosomes.
- Key organelles include:
  - Nucleus: Stores DNA; contains nucleolus for ribosome synthesis.
  - Mitochondria: Known as the powerhouse of the cell; site of ATP production through cellular respiration.
  - Endoplasmic Reticulum (ER):
    - Rough ER: Studded with ribosomes, important for protein synthesis.
    - Smooth ER: Lacks ribosomes, involved in lipid synthesis.
  - Golgi Apparatus: Modifies, sorts, and packages proteins and lipids for transport.
  - Lysosomes: Contain digestive enzymes to process waste materials.
  - Chloroplasts: Found in plant cells, responsible for photosynthesis.

Cellular Respiration:
- Converts glucose and oxygen into ATP, carbon dioxide, and water.
- Comprises three main stages: Glycolysis, Krebs Cycle, and Electron Transport Chain.
Photosynthesis:
- Transforms light energy into chemical energy (glucose) using carbon dioxide and water.
- Takes place in chloroplasts and includes light-dependent reactions and the Calvin cycle (light-independent reactions).
Cell Division:
- Mitosis: Process for somatic cell division, resulting in two identical daughter cells for growth and repair.
- Meiosis: Generates four genetically diverse daughter cells for gamete formation.
Protein Synthesis:
- Transcription: Process of synthesizing mRNA from DNA in the nucleus.
- Translation: Converting mRNA into a polypeptide chain at ribosomes.
Cell Signaling:
- Involves communication between cells using signaling molecules (e.g., hormones, neurotransmitters).
- Consists of reception, transduction, and response mechanisms to relay information.