Biology Chapter - Feedback Mechanisms and Systems

Positive and Negative Feedback Loops

• Positive feedback amplifies a change, pushing the system further away from equilibrium.
  • Example: Childbirth, where contractions trigger further contractions until the baby is born.
• Negative feedback counteracts a change, bringing the system back to equilibrium.
  • Example: Body temperature regulation, where sweating cools the body down when it gets too hot.

Respiratory System and Exercise

• Increased breathing rate: Delivers more oxygen to working muscles.
• Increased lung capacity: Allows for greater gas exchange.
• Increased blood flow: Delivers oxygen and removes carbon dioxide more efficiently.

Circulatory System

• Essential for transporting nutrients and oxygen throughout the body.
• Carries waste products away from cells.
• Helps regulate body temperature.

Liver and Urea Production

• The liver works with the excretory system to produce urea.
• Urea is a waste product of protein metabolism.
• The excretory system removes urea from the body through urine.

Digestive Tract Malfunctions

• Organ malfunction can disrupt nutrient absorption and digestion.
• Example: Pancreas malfunction can lead to maldigestion and nutrient deficiencies.

Parasite Effects on Body Systems

• Parasites can affect multiple body systems by stealing nutrients, damaging organs, and causing inflammation.
• Symptoms:
  • Digestive problems (e.g., diarrhea, vomiting)
  • Weakened immune system
  • Anemia
  • Muscle aches

Body Systems Involved in Childbirth

• Reproductive system: Produces hormones and develops the fetus.
• Musculoskeletal system: Provides strength and support for labor.
• Nervous system: Controls contractions and pain perception.

Hormone Release and Function

• Hormones are chemical messengers released by endocrine glands.
• Secretion is often controlled by negative feedback loops.
• Target specific cells and organs to regulate various functions.

Respiratory System and Gas Exchange

• Oxygen is inhaled and absorbed into the bloodstream through the lungs.
• Carbon dioxide is exhaled as a waste product of cellular respiration.

Blood Glucose Regulation

• Pancreas releases insulin to lower blood glucose levels.
• Pancreas releases glucagon to raise blood glucose levels.
• Liver stores and releases glucose as needed to maintain balance.

Immune System and Viral Defense

• White blood cells recognize and destroy viruses.
• Antibodies are produced to neutralize viruses.
• The immune system adapts over time to create immunity to specific viruses.

Plant Systems

Waxy Cuticle

• Protects the plant from water loss through transpiration.
• Prevents desiccation in dry environments.

Vascular Plants

• Vascular tissue (xylem and phloem) enables the transport of water and nutrients throughout the plant.
• Allows for taller growth by providing structural support.

Water and Mineral Absorption

• Roots absorb water and minerals from the soil.
• Root hairs increase surface area for efficient absorption.

Stomata

• Open stomata allow gas exchange for photosynthesis and respiration.
• Closed stomata reduce water loss through transpiration.
• Conditions for opening:
  • High light intensity
  • Low carbon dioxide concentration
• Conditions for closing:
  • Low light intensity
  • High carbon dioxide concentration

Plant Tropisms

• Tropisms are directional growth responses to stimuli.
• Phototropism: Growth towards light.
• Geotropism: Growth in response to gravity.
• Thigmotropism: Growth in response to touch.

Drought Response

• Plants maximize water retention by closing stomata, shedding leaves, and developing deep roots.

Fern and Moss Adaptations

• Ferns have vascular tissue, allowing for larger size and greater height.
• Mosses lack vascular tissue, limiting their size and growth.

Stomata Location

• Located on the underside of leaves, reducing water loss through transpiration.

Flower Parts and Functions

• Sepals: Protect the bud before it opens.
• Petals: Attract pollinators.
• Stamens: Produce pollen (male reproductive organ).
• Pistil: Contains the ovary and stigma (female reproductive organ).

Plant Phyla

• Bryophyta: Mosses, liverworts, hornworts.
• Pteridophyta: Ferns, horsetails, whisk ferns.
• Coniferophyta: Conifers (e.g., pines, firs, spruces).
• Anthophyta: Flowering plants.

Cellular Energetics

Photosynthesis

• Oxygen comes from water during the light dependent reaction of photosynthesis.
• The light dependent reactions use light energy to form ATP (adenosine triphosphate), a form of chemical energy.
• The light independent reactions use this energy to convert carbon dioxide into glucose.

ATP and ADP

• ATP (adenosine triphosphate) stores chemical energy in the bonds between its phosphate groups.
• ADP (adenosine diphosphate) is produced when ATP releases energy by breaking a phosphate bond.

Cellular Respiration

• Provides energy for cells by breaking down glucose.
• Occurs in three stages: glycolysis, the Krebs cycle, and electron transport chain.
• Produces ATP as a usable source of energy.

Lactic Acid Fermentation

• Occurs in anaerobic conditions (without oxygen).
• Converts pyruvate to lactic acid, allowing glycolysis to continue producing a small amount of ATP.

Gizmo Activity

• Photosynthesis produces oxygen, which forms bubbles in the gizmo.
• Color changes in the solution reflect the production of chlorophyll, a pigment essential for photosynthesis.

Light and Photosynthesis

• Light provides the energy for the light dependent reactions of photosynthesis.

Cellular Process and ATP Production

• Cellular respiration is the primary process that generates ATP.

Photosynthesis and Cellular Respiration Equations

• Photosynthesis: 6CO2 + 6H2O + light energy → C6H12O6 + 6O2
• Cellular Respiration: C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + ATP energy

Animal Systems

• Positive Feedback Loop: A change in a system triggers a response that amplifies that change. Example: Labor contractions intensify.
• Negative Feedback Loop: A change in a system triggers a response that counteracts that change. Example: Blood sugar regulation.
• Respiratory System & Exercise: Increases breathing rate and depth to deliver more oxygen to muscles and remove carbon dioxide.
• Circulatory System: Transports oxygen, nutrients, and waste products throughout the body.
• Liver & Urea Production: The liver works with the excretory system to filter waste products from the blood and produce urea, which is excreted in urine.
• Digestive Tract Malfunction: Can cause problems with nutrient absorption, digestion, and waste removal.
• Parasite Effects: Parasites can affect multiple body systems by consuming nutrients, causing inflammation, and disrupting normal function.
• Childbirth Systems: The reproductive, muscular, and nervous systems are all involved in childbirth.
• Hormone Release: Hormones are released from glands and travel through the bloodstream to target cells, where they trigger specific responses.
• Respiratory System Gas Exchange: Oxygen is absorbed from the air into the lungs and carbon dioxide is released from the lungs into the air.
• Glucose Regulation, Virus Defense, & Feedback: The endocrine, immune, and nervous systems are involved in regulating blood glucose levels, defending against viruses, and maintaining homeostasis through feedback loops.

Plant Systems

• Waxy Cuticle: Prevents water loss from the leaves.
• Vascular Plant Survival on Land: Vascular tissue (xylem and phloem) allows for efficient transport of water and nutrients throughout the plant, enabling it to survive on land.
• Water & Mineral Absorption: Roots absorb water and minerals from the soil.
• Stomata Opening & Closing: Stomata open when conditions are favorable for photosynthesis (adequate light and moisture) and close when water is scarce.
• Tropisms: Plant growth responses to external stimuli.
  • Phototropism: Growth towards light.
  • Gravitropism: Growth in response to gravity.
  • Thigmotropism: Growth in response to touch.
• Drought Response: Plants maximize water retention by minimizing water loss through transpiration and closing stomata.
• Fern & Moss Adaptations: Ferns have vascular tissue, enabling them to grow taller than mosses.
• Stomata Location: Stomata are located on the underside of leaves.
• Flower Parts & Functions:
  • Sepal: Protects the developing bud.
  • Petal: Attracts pollinators.
  • Stamen: Produces pollen (male reproductive structure).
  • Pistil: Contains the ovary and stigma (female reproductive structure).
• Plant Phyla:
  • Bryophyta (Mosses): Non-vascular, require moist environments.
  • Pteridophyta (Ferns): Vascular, have spores for reproduction.
  • Coniferophyta (Conifers): Vascular, have seeds in cones.
  • Anthophyta (Flowering Plants): Vascular, have seeds in flowers and fruits.

Cellular Energetics

• Photosynthesis Oxygen Source: Oxygen comes from the breakdown of water molecules.
• Light-Dependent vs. Light-Independent Reactions:
  • Light-dependent: Occurs in the chloroplast's thylakoid membranes, uses light energy to generate ATP and NADPH.
  • Light-independent: Occurs in the chloroplast's stroma, uses ATP and NADPH to convert carbon dioxide into sugar.
• ATP/ADP Energy Storage & Release: Energy is stored in the bonds of ATP and released when ATP is broken down into ADP and a phosphate group.
• Cellular Respiration Functions:
  • Glycolysis: Breaks down glucose into pyruvate.
  • Krebs Cycle: Breaks down pyruvate and generates electron carriers.
  • Electron Transport Chain: Uses electron carriers to generate ATP.
• Lactic Acid Fermentation: A process that occurs in the absence of oxygen, where pyruvate is converted into lactic acid to produce a small amount of ATP.
• Photosynthesis Gizmo Activity: Demonstrates the correlation between light intensity and the rate of photosynthesis, observed through oxygen production and color changes.
• Light & Photosynthesis: Photosynthesis is directly dependent on light energy.
• Cellular Process & ATP Production: Cellular respiration is the primary process for ATP production in cells.
• Photosynthesis & Cellular Respiration Equations:
  • Photosynthesis: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
  • Cellular Respiration: C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + ATP
• Cellular Respiration & Photosynthesis Diagrams: These diagrams illustrate the steps involved in each process, including organelles, reactants, and products.

Explore the concepts of positive and negative feedback loops, and their roles in biological systems. Understand the intricacies of the respiratory and circulatory systems, and discover the liver's function in urea production. This quiz will test your knowledge on crucial physiological processes.