Biology: Cell Structure, Genetics, and Evolution

Cell Structure and Function

• Cell Types:
  • Prokaryotic (bacteria) - no nucleus, smaller.
  • Eukaryotic (plants, animals) - nucleus, membrane-bound organelles.
• Organelles:
  • Nucleus: Contains DNA, control center.
  • Mitochondria: Energy production (ATP).
  • Ribosomes: Protein synthesis.
  • Endoplasmic Reticulum: Synthesizes proteins (rough) and lipids (smooth).
  • Golgi Apparatus: Modifies, sorts, and packages proteins.
  • Lysosomes: Digests waste materials.

Genetics

• DNA Structure:
  • Double helix made of nucleotides (adenine, thymine, cytosine, guanine).
• Gene Expression:
  • Transcription: DNA to mRNA.
  • Translation: mRNA to protein.
• Mendelian Genetics:
  • Dominant and recessive traits.
  • Punnett squares for predicting offspring genotypes.

Evolution

• Natural Selection: Survival of organisms best adapted to their environment.
• Speciation: Formation of new and distinct species over time.
• Common Ancestry: All living organisms share a common ancestor.

Ecology

• Ecosystems: Interactions between organisms and their environment.
• Biomes: Large ecological areas (e.g., forests, deserts).
• Food Chains/Webs: Energy flow from producers to consumers to decomposers.

Human Biology

• Organ Systems:
  • Circulatory: Transports blood and nutrients.
  • Respiratory: Gas exchange (oxygen and carbon dioxide).
  • Digestive: Breaks down food, absorbs nutrients.
• Homeostasis: Maintaining stable internal conditions (temperature, pH).

Microbiology

• Bacteria: Unicellular, can be beneficial (gut flora) or pathogenic.
• Viruses: Acellular, require a host to replicate, can cause diseases.
• Fungi: Decomposers, important for nutrient cycling.

Plant Biology

• Photosynthesis: Conversion of light energy into chemical energy (glucose).
• Plant Structures:
  • Roots: Absorb water and nutrients.
  • Stems: Support and transport.
  • Leaves: Main site for photosynthesis.

Biochemistry

• Macromolecules:
  • Carbohydrates: Energy storage (glucose).
  • Proteins: Functions include enzymes and structural support.
  • Lipids: Energy storage, cell membranes.
  • Nucleic Acids: DNA and RNA, genetic information.

Biotechnology

• Genetic Engineering: Modification of an organism's DNA (e.g., CRISPR).
• Cloning: Creating a genetically identical organism.
• Biopharmaceuticals: Using biological processes to produce medications.

Cell Structure and Function

• Prokaryotic cells, like bacteria, lack a nucleus and have a smaller size compared to eukaryotic cells, which have a defined nucleus and membrane-bound organelles.
• The nucleus serves as the control center of the cell, housing DNA that regulates cellular activities.
• Mitochondria are responsible for ATP production, vital for energy supply.
• Ribosomes are essential for synthesizing proteins, crucial for various cellular functions.
• The endoplasmic reticulum (ER) synthesizes proteins (rough ER) and lipids (smooth ER), contributing to overall cellular metabolism.
• The Golgi apparatus modifies, sorts, and packages proteins for transport to various destinations within or outside the cell.
• Lysosomes function as the digestive system of the cell, breaking down waste materials and cellular debris.

Genetics

• DNA is structured as a double helix and consists of nucleotides: adenine, thymine, cytosine, and guanine.
• Gene expression involves two key processes: transcription, where DNA is converted to mRNA, and translation, where mRNA is translated into proteins.
• Mendelian genetics emphasizes the inheritance of dominant and recessive traits, often modeled using Punnett squares for predicting offspring genotypes.

Evolution

• Natural selection explains how organisms best adapted to their environment tend to survive and reproduce, influencing the development of species.
• Speciation describes the evolutionary process by which new and distinct species arise over time.
• All living organisms share a common ancestor, underscoring the interconnectedness of life.

Ecology

• Ecosystems encompass the interactions between living organisms and their physical environment, forming a dynamic and interdependent web of life.
• Biomes are categorized as large ecological areas with distinct climates and flora and fauna, such as forests and deserts.
• Food chains and food webs illustrate energy transfer, showing how energy flows from producers to consumers and finally to decomposers.

Human Biology

• The circulatory system is responsible for transporting blood, nutrients, and gases throughout the body.
• The respiratory system facilitates gas exchange, specifically oxygen intake and carbon dioxide expulsion.
• The digestive system breaks down food, enabling nutrient absorption for energy and growth.
• Homeostasis refers to the body's ability to maintain stable internal conditions, including temperature and pH levels.

Microbiology

• Bacteria are unicellular organisms that can be beneficial, such as those found in gut flora, or pathogenic, causing diseases.
• Viruses are acellular entities that require a host cell for replication and can lead to various diseases.
• Fungi play a critical role as decomposers in ecosystems, aiding in nutrient cycling.

Plant Biology

• Photosynthesis is the process through which plants convert light energy into chemical energy stored as glucose.
• Plant structures: roots absorb water and nutrients, stems provide support and transport materials, while leaves are primarily responsible for photosynthesis.

Biochemistry

• Macromolecules include carbohydrates, which serve as energy storage (e.g., glucose), proteins that function in enzymatic and structural capacities, lipids for energy storage and membrane structure, and nucleic acids (DNA and RNA) that carry genetic information.

Biotechnology

• Genetic engineering involves the modification of an organism's DNA, with techniques such as CRISPR allowing for precise changes.
• Cloning refers to creating genetically identical organisms, which has implications in research and medical fields.
• Biopharmaceuticals leverage biological processes to develop medications, enhancing therapeutic options.

This quiz covers essential topics in biology, including cell structure and function, the fundamentals of genetics, and principles of evolution. Explore concepts such as prokaryotic and eukaryotic cells, DNA structure, natural selection, and more. Perfect for students looking to reinforce their understanding of these critical biological concepts.