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; examples include bacteria.
  • Eukaryotic: Has a nucleus; larger; includes plants, animals, fungi, and protists.

• Cell Organelles:

  • Nucleus: Contains genetic material (DNA).
  • Mitochondria: Powerhouse of the cell; site of ATP (energy) production.
  • Ribosomes: Sites of protein synthesis.
  • Endoplasmic Reticulum (ER):
    • Rough ER: Studded with ribosomes; synthesizes proteins.
    • Smooth ER: Synthesizes lipids and detoxifies.
  • Golgi Apparatus: Modifies, sorts, and packages proteins and lipids.

Genetics

• DNA Structure:

  • Double helix composed of nucleotides (A, T, C, G).
  • Base pairing: A-T, C-G.

• Gene Expression:

  • Transcription: DNA to mRNA.
  • Translation: mRNA to protein.

• Mendelian Genetics:

  • Laws of Segregation and Independent Assortment.
  • Phenotype vs. Genotype: Observable traits vs. genetic makeup.

Evolution

• Natural Selection:

  • Mechanism by which organisms better adapted to their environment tend to survive and produce more offspring.

• Speciation:

  • The process by which new species arise.

• Evidence for Evolution:

  • Fossil records, comparative anatomy, molecular biology, and biogeography.

Ecology

• Levels of Organization:

  • Individual, Population, Community, Ecosystem, Biome, Biosphere.

• Ecosystem Dynamics:

  • Energy flow (food chains/webs) and nutrient cycling (carbon, nitrogen cycles).

• Biomes:

  • Large ecological areas with distinct climates and organisms (e.g., tundra, rainforest, desert).

Human Biology

• Organ Systems:

  • Circulatory, Respiratory, Digestive, Nervous, Musculoskeletal, Reproductive, Endocrine, Immune, Integumentary, Excretory.

• Homeostasis:

  • The process of maintaining a stable internal environment despite external changes.

• Cellular Respiration:

  • Process by which cells convert glucose and oxygen into energy (ATP), carbon dioxide, and water.

Microbiology

• Types of Microorganisms:

  • Bacteria, Viruses, Fungi, Protozoa, Algae.

• Infection and Immunity:

  • Pathogens: Disease-causing agents.
  • Immune response: Innate (immediate) vs. adaptive (specific) immunity.

Plant Biology

• Photosynthesis:

  • Process by which plants convert light energy into chemical energy (glucose).
  • Occurs in chloroplasts; involves light-dependent and light-independent reactions.

• Plant Structures:

  • Roots: Absorb water and nutrients.
  • Stems: Support and transport.
  • Leaves: Site of photosynthesis.

Biochemistry

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

Biotechnology

• Techniques:

  • Genetic engineering (CRISPR), cloning, and PCR (Polymerase Chain Reaction).

• Applications:

  • Medicine (gene therapy), agriculture (GMOs), and environmental science (bioremediation).

Cell Biology

• Cell Theory comprises three fundamental principles about living organisms and cells, emphasizing their role as the basic unit of life.
• Two main types of cells exist: Prokaryotic cells lack a nucleus and are typically smaller (e.g., bacteria), while Eukaryotic cells possess a nucleus and are larger, including plants, animals, fungi, and protists.
• Key cell organelles include the nucleus (stores DNA), mitochondria (ATP production), ribosomes (protein synthesis), rough endoplasmic reticulum (ER) (protein synthesis site), smooth ER (lipid synthesis and detoxification), and the Golgi apparatus (protein and lipid modification and packaging).

Genetics

• DNA is structured as a double helix formed by nucleotides, utilizing base pairing rules: adenine pairs with thymine, and cytosine pairs with guanine.
• Gene expression involves two main processes: transcription converts DNA into messenger RNA (mRNA), and translation converts mRNA into proteins.
• Mendelian genetics highlights key principles such as the laws of segregation and independent assortment, with distinctions between phenotypes (observable traits) and genotypes (genetic composition).

Evolution

• Natural selection is a key mechanism of evolution, highlighting how individuals adapted to their environments have higher survival and reproductive rates.
• Speciation is the process through which new species develop over time.
• Evidence of evolution stems from various sources, including fossil records, comparative anatomy, molecular biology, and biogeographical studies.

Ecology

• Ecological organization is structured in levels: individual, population, community, ecosystem, biome, and biosphere.
• Ecosystem dynamics encompass energy flow through food chains and webs and nutrient cycling involving carbon and nitrogen.
• Biomes are large ecological regions characterized by specific climates and distinctive organisms, such as tundras, rainforests, or deserts.

Human Biology

• The human body comprises multiple organ systems, including circulatory, respiratory, digestive, nervous, musculoskeletal, reproductive, endocrine, immune, integumentary, and excretory systems.
• Homeostasis refers to maintaining a stable internal environment amidst external fluctuations, critical for healthy function.
• Cellular respiration is the metabolic process where cells convert glucose and oxygen into energy (ATP), alongside producing carbon dioxide and water.

Microbiology

• Microorganisms encompass various types, including bacteria, viruses, fungi, protozoa, and algae.
• Infections are caused by pathogens, and the immune response can be classified as innate—immediate defense mechanisms—or adaptive, which is specific and improves over time.

Plant Biology

• Photosynthesis allows plants to transform light energy into chemical energy in the form of glucose, occurring within chloroplasts and involving both light-dependent and light-independent reactions.
• Key plant structures include roots (absorb water and nutrients), stems (provide support and transport), and leaves (main site for photosynthesis).

Biochemistry

• Four major macromolecules include carbohydrates (primary energy source), proteins (composed of amino acids, serve various functions), lipids (store energy and form cell membranes), and nucleic acids (DNA and RNA, responsible for genetic information).

Biotechnology

• Techniques in biotechnology include genetic engineering (notably CRISPR), cloning, and PCR (Polymerase Chain Reaction).
• Applications span multiple fields, including medicine (gene therapy), agriculture (genetically modified organisms), and environmental science (bioremediation).

This quiz covers essential concepts in cell biology and genetics, including cell theory, types of cells, organelles, DNA structure, and gene expression. Test your understanding of key principles such as Mendelian genetics and the functions of cellular structures.