Gas exchange and transpiration

• Gas exchange occurs in the lungs, where oxygen enters the blood and carbon dioxide is removed.
• This process ensures tissues receive oxygen and carbon dioxide is expelled.

Lung Adaptations for Gas Exchange

• Large surface area facilitates efficient diffusion.
• Thin alveolar walls enable quick gas diffusion.
• Rich blood supply maintains concentration gradients.
• Moist surfaces aid gas dissolution.
• Ventilation mechanism replenishes air in the lungs.
• Elasticity helps in expelling air.

Oxygen Concentration Gradient

• A high oxygen concentration in the lungs and a low concentration in blood capillaries are essential for efficient gas exchange.
• Oxygen moves from the alveoli to blood capillaries, binding to hemoglobin in red blood cells.

Consequences of Water Evaporation from Leaves (Transpiration)

• Transpiration facilitates plant cooling, nutrient transport, gas exchange, and overall growth.
• Transpiration maintains plant hydration and functionality.

Gas Exchange in Large Organisms

• Large organisms need specialized systems for gas exchange because of their size.
• Adaptations include respiratory organs, circulatory systems, and respiratory pigments.

Elements of Plan Diagrams

• Outline and shape of the subject.
• Arrangement of components.
• Scale of the diagram.
• Dimensions for size.
• Labels for identification.

Thorax Expansion

• Contraction of the diaphragm and external intercostal muscles expands the thorax.
• Expansion increases chest cavity volume and reduces internal lung pressure, allowing air to enter the lungs.

Tidal Volume

• Tidal volume is the amount of air inhaled or exhaled during normal breathing.
• A healthy range is approximately 0.5 liters per breath.
• Tidal volume can be affected by body size, age, health conditions, and physical activity.

Ventilation Rate

• Ventilation rate measures the amount of air entering and exiting the lungs in a given time.
• VR = Tidal volume multiplied by Breathing rate.
• Ventilation rate is influenced by exercise, age, health conditions, and emotions.

Blood Vessels: Arteries, Veins, and Capillaries

• Arteries have thick walls, narrow lumen, and high pressure to carry blood away from the heart.
• Veins have thinner walls, wide lumen, and valves for low-pressure blood return to the heart.
• Capillaries are one cell thick, enabling efficient gas and nutrient exchange.

Xylem Adaptations and Function

• Xylem transports water and dissolved minerals from roots to leaves and provides structural support.
• Hollow Tubes: Dead cells without cytoplasm allow uninterrupted water flow.
• Lignified Cell Walls: Walls reinforced with lignin strengthen vessels and prevent collapse.
• Continuous Tubes: Vessels joined end-to-end form continuous tubes for efficient transport.
• Pits: Small openings allow lateral water movement between vessels.

Water Transport

• Water is transported through the xylem via the transpiration stream.
• Water is absorbed by root hairs through osmosis and moves into the root xylem.
• Water travels upward due to capillary action, driven by cohesion and adhesion.
• Transpiration, or water evaporation from stomata, creates negative pressure that pulls water upward.

Blood Vessel Identification

• Arteries Wall Thickness: Thick, muscular, and elastic. Lumen Size: Narrow. Valves: None. Blood Flow: Away from the heart. Pressure: High. Blood: Mostly oxygenated.
• Veins Wall Thickness: Thin, less muscular. Lumen Size: Wide. Valves: Present. Blood Flow: Toward the heart. Pressure: Low. Blood: Mostly deoxygenated.

Causes of High Blood Pressure

• High salt intake.
• Poor diet.
• Lack of exercise.
• Obesity.
• Excessive alcohol consumption.
• Smoking.
• Kidney disease.
• Diabetes.
• Hormonal disorders.
• Family history.
• Aging.
• Chronic stress.
• Poor sleep.

Coral Reef Conditions

• Temperature: 23-29°C.
• Sunlight: Needed by zooxanthellae for photosynthesis.
• Salinity: Thrives in marine environments.
• Water Clarity.
• Wave Action: Supplies oxygen and removes waste.
• Substrate: Provides a base for attachment.

Transects

• A transect is a straight line along which data is collected to study species distribution changes across an environmental gradient.
• How Transects Are Used:
  • A tape measure is laid out, and samples are taken at regular intervals using quadrats or direct observation.
  • Used to study how abiotic factors influence species distribution.
• Types of Transects:
  • Line: Records species touching the line at set intervals.
  • Belt: Uses quadrats along the transect to record species density or abundance.

Quadrats

• A quadrat is a square frame used to estimate population size, density, or distribution in a specific area.
• How Quadrats Are Used:
  • Placed randomly or systematically in a study area.
  • Organisms within the quadrat are counted and recorded.
  • Multiple quadrats are sampled to improve accuracy.
• Types of Quadrats: - Random - Systematic: Placed on random intervals along a transect

Ecological Niches: Aerobes vs. Anaerobes

• Obligate Aerobes:
  • Require oxygen to survive and grow.
  • Use aerobic respiration.
  • Examples: Humans, Mycobacterium tuberculosis.
• Facultative Anaerobes:
  • Can survive with or without oxygen but prefer oxygen.
  • Use aerobic respiration when oxygen is present; switch to fermentation or anaerobic respiration in the oxygen's absence.
  • Examples: Escherichia coli (E. coli), Yeast.
• Obligate Anaerobes:
  • Cannot survive in oxygen; oxygen is toxic to them.
  • Use fermentation or anaerobic respiration because oxygen disrupts their metabolic processes.
  • Examples: Clostridium botulinum, Clostridium tetani.

Holozoic

• Organisms ingest, digest, and absorb complex organic food.
• Involves ingestion, digestion, absorption, assimilation, and egestion.
• Examples: Humans, animals, amoeba.

Saprotrophic Nutrition

• Organisms obtain nutrients by decomposing and absorbing dead organic matter.
• Secrete digestive enzymes externally to break down complex organic matter before absorbing nutrients.
• Examples: Fungi, some bacteria.