Adaptive Immunity and Innate Defense Quiz

Module 3: Transport and Circulation of Materials

• Lesson 3.1: Trends and Strategies Used by Organisms to Transport Materials

• This lesson covers the various methods organisms use to transport essential materials.

• Single-celled organisms like Amoeba and Paramecium use simple diffusion.

• Multicellular organisms employ more complex systems.

• Lesson 3.2: Transport Mechanisms in Plants

• Plants' vascular tissues (xylem and phloem) are crucial for transport.

• Xylem transports water and dissolved minerals from roots to leaves via transpiration.

• Phloem transports organic nutrients (sugars, amino acids) from sites of production (like leaves) to other parts of the plant via translocation.

Introduction

• Efficient transport of nutrients, gases, and waste products is vital for all living organisms.
• This allows each cell to receive required resources and eliminate byproducts.

Adaptations by Various Organisms to Transport Materials

• Non-vascular plants: Lack specialized vascular tissue; rely on diffusion and osmosis for cell-to-cell transport, limiting their size to typically moist environments.

• Vascular plants: Have specialized vascular tissue (xylem and phloem) enabling them to grow bigger and transport substances over longer distances

• Gastrovascular Cavity: Found in animals like sea jellies, flatworms; a central cavity acting as both a mouth and an anus; fluid bathes tissues, facilitating gas and nutrient exchange. In flatworms, the GVC is a simple, branched structure for nutrient absorption and waste removal.

• Circulatory System:

  • Composed of fluid (blood), vessels or pathways, and a pump(heart) circulating the fluid throughout the body.
  • Types: Open systems (e.g., in some mollusks and arthropods) and closed systems (e.g., in annelids, cephalopods, and vertebrates). Hemolymph in open systems bathes organs directly, while blood in closed systems is contained inside vessels, which facilitates more efficient transport.

Overview of the Circulatory Systems of Different Animals

• Diagrams illustrating circulatory systems in fish, amphibians, reptiles, and mammals. These depict systems variations and complexities.

Transport Mechanisms in Plants (continued)

• Xylem is a complex tissue with specialised cells:
  • Tracheids
  • Vessel elements
  • Xylem fibers
  • Xylem Parenchyma
• Phloem is a complex tissue with specialized cells:
  • Sieve tubes
  • Phloem fibers
  • Phloem parenchyma

Three Major Pathways

• Plants employ the apoplast, transmembrane, and symplast pathways for transport.
• Apoplast: Water and dissolved minerals move through the porous cell walls outside the plasma membrane. It is fast but does not involve the cell interior
• Symplast: Water and dissolved minerals move through the interconnected cytoplasm of cells via plasmodesmata. It is slower but permits more control over which materials move across membranes
• Transmembrane: Water and dissolved minerals cross both the cell membrane and cell walls. This process provides the highest level of control.

Transpiration

• Transpiration is the process by which water is lost from plants through evaporation from the leaves.
• This creates a negative pressure which draws water up the xylem in a process known as 'the cohesion-tension hypothesis'.

Translocation in The Phloem sap

• Phloem transports organic nutrients produced during photosynthesis in the leaves to other plant parts like roots and fruits.
• Sugar molecules passively transported through the phloem

Summary (Module 3)

• Organisms have various adaptations for circulating materials to support survival. The complexity of these systems highlights diversity in biology.

The Human Cardiovascular System

• Lesson 3.3-3.4: This section describes the structure and function of the human cardiovascular system.
• Heart: A muscular organ pumping blood; includes four chambers (two atria, two ventricles), valves preventing backflow, and the pericardium.
• Blood Vessels: Arteries, arterioles, capillaries, venules, veins; involved in transporting oxygenated blood from the heart to the body and carrying deoxygenated blood back to the heart.

The Blood

• Blood is the body's liquid transport system, consisting of plasma, red blood cells (carrying oxygen), white blood cells (immune defense), and platelets (clotting).

Red Blood Cells

• Biconcave disk-shaped cells, carrying oxygen throughout the body using hemoglobin.

White Blood Cells

• Several types with different functions, crucial for immune responses and defense against germs.

Platelets

• Tiny cell fragments, essential for blood clotting, when blood vessels are injured.

Blood Circulation

• The Circulatory system runs on two paths:
• Pulmonary circulation: supplies blood with oxygen, from the lungs to the heart.
• Systemic circulation: delivers oxygenated blood around the body, and carries deoxygenated blood from the body to the heart, to be re-oxygenated through the pulmonary circulation.

Module 4: Immunity

• Lesson 4.1: Trends and various strategies used by organisms for defense against diseases.

• This describes diverse defense mechanisms across living organisms. Several examples of pathogens are provided.

• Innate Immunity of Poriferans (Sponges):

  • Filter-feeding mechanism protects against large concentrations of pathogens in water.
  • Sponges produce secondary metabolites which have antibiotic properties.

• Innate Immunity of Cnidarians (Jellyfish, Anemones, etc.):

  • Utilize toxins (palytoxins and hypnotoxins) for defense against predators.

• Innate Immunity of Helminthes (Worms):

  • Employ phagocytes and antimicrobial proteins/compounds to defend against pathogens.

• Innate Immunity of Mollusks (Snails, Clams, etc.):

  • Rely on hard shells as a first line of defense.
  • Internal immune cells (hematocytes) engulf and destroy pathogens.

• Innate Immunity of Arthropods (Insects, Spiders, etc.):

  • External exoskeleton provides a barrier.
  • Hemocytes and antimicrobial peptides play a role in killing pathogens that enter the body.

• Cellular Innate Defenses of Vertebrates (Humans):

  • Involves phagocytic cells (neutrophils, macrophages, dendritic cells), natural killer cells, and antimicrobial peptides and proteins.

• Barrier defenses of the human body (innate immunity):

• Skin - physical barrier, sebum and sweat

• Nasal hairs and cilia- trapping and removing foreign particles.

• Long Urethra- slows the passage of bacteria

• Friendly bacteria- maintain acidic conditions

• The lymphatic system:- Transports lymph throughout the body which facilitates the movement of immune cells and removal of waste.

Overview of Innate Immunity

• Innate immunity offers broad, non-specific defense against foreign substances.
• Innate immune response triggered immediately, while acquired immunity develops gradually over time.

Distinction between Innate vs Adaptive Immunity

• Innate immunity is immediate, while adaptive immunity takes time to develop.

• Innate immunity provides broad protection, while adaptive immunity's response is targeted.

• Cells-mediated response:

  • Immune response to infected cells.
  • Carried out by T cells.

• Humoral response:

  • Immune response to freely floating antigens.
  • Carried out by B cells.

Specific Defenses (Adaptive Immunity):

• Antigen: A foreign molecule or microbe triggering an immune response.
• Antibody: A protein produced by B cells, targeting specific antigens.
• Recognition: When pathogen's surface protein (antigen) gets recognized by the adaptive immune system.
• Cell proliferation: Lymphocytes (B & T cells) multiply to fight the specific pathogen.
• Immunological memory: A stronger and faster response to previously encountered pathogens.

Test your knowledge on adaptive and innate immunity with this quiz. Explore the key components, cell types, and functions of both immune systems. Suitable for students studying biology or immunology.