Comprehensive Study Guide on Biological Systems and Ecosystems

Body Systems

Cellular Hierarchy

Learning Intention

  • Identify the organisation of the body from cells to tissues, organs and body systems.

Concepts

  • Cellular Hierarchy involves the organisation from:

    • Cell → Tissue → Organ → Organ System → Organism

  • Each type of cell has a unique function and works together with other cells to ensure the survival of an organism. (Word bank: together, function, organism)

Tissues and Organs

  • Tissues are groups of specialised cells working together to perform a specific function.

  • An organ is a combination of tissues and cells that perform a specific function in the body.

  • Different organs can work together to form organ systems. For example, the heart and blood vessels work together as part of the circulatory system.

  • All organ systems working together form an organism.

Differentiated Cell Types

  • Tissues Include:

    • Muscle tissue cells

    • Nerve cells

    • Epithelial cells

    • Connective cells

The Digestive System

Learning Intention

  • Identify the role, specialised cells and major organs that make up the digestive system.

Types of Digestion

  • Physical Digestion: The mechanical breakdown of food into smaller pieces.

  • Chemical Digestion: The enzymatic breakdown of food into simpler molecules.

Main Organs of the Digestive System

  • Chews and grinds food into smaller pieces, aiding swallowing and digestion.

  • Saliva moistens food and contains amylase, an enzyme that breaks down starch into simpler sugars.

The Mouth

The Oesophagus

  • Transports food and liquids from the mouth to the stomach through coordinated muscular contractions known as peristalsis.

The Stomach

  • Food stays for about 1–6 hours, turning it into a liquid mixture through churning by stomach walls.

  • Produces hydrochloric acid (HCl) and enzymes to aid digestion and kill bacteria.

  • Protects itself by producing mucus to coat the stomach walls.

The Liver

  • The largest internal organ with multiple functions.

  • Produces bile to aid fat digestion.

The Small Intestine

  • A long tube (up to 6 meters) where digestion continues, breaking food into smaller molecules.

  • Lined with tiny folds called villi covered in enterocytes with microvilli, enhancing nutrient absorption.

The Pancreas

  • Produces pancreatic juice that breaks down carbohydrates, fats, and proteins; this juice enters the digestive system in the small intestine.

The Large Intestine

  • Absorbs water and nutrients back into the body; forms waste into faeces excreted through the anus.

The Circulatory System

Learning Intention

  • Identify the role, specialised cells and major organs that make up the circulatory system.

Function of the Circulatory System

  • Acts as the body’s transportation system, including:

    • Blood: Transports water, nutrients, CO2, and waste products.

    • Red Blood Cells: Transport oxygen for cellular respiration.

The Heart

  • Functions as a double pump:

    • Left Side: Receives oxygen-rich blood from lungs and pumps it to the body.

    • Right Side: Receives deoxygenated blood from the body and pumps it to the lungs.

The Respiratory System

Learning Intention

  • Identify the role, specialised cells and major organs that make up the respiratory system.

Function of the Respiratory System

  • Supplies oxygen to red blood cells and removes carbon dioxide from the blood.

  • Oxygen movement:

    • Nose/Mouth ➔ Trachea ➔ Bronchi ➔ Bronchioles ➔ Alveoli

    • Oxygen enters blood in the alveoli, is carried by red blood cells to cells for cellular respiration.

Cellular Respiration

  • The process involves chemical changes in living cells to release energy; oxygen transport is vital for cellular respiration, ensuring energy is available to cells.

Removing Foreign Particles

  • Ciliated cells line the bronchi and bronchioles, having cilia that sweep mucus and debris out of the lungs.

The Excretory System

Learning Intention

  • Identify the role, specialised cells and major organs that make up the excretory system.

Components of The Excretory System

  • Organs: Liver, kidneys, bladder, skin.

  • Functions to remove waste products generated by cellular metabolism and maintain water and salt balance.

The Liver

  • Removes harmful metabolic wastes like ammonia, converting it into urea, which is excreted in urine.

The Urinary System

  • Filters blood to remove wastes and maintain fluid balance; kidneys filter blood, forming urine that travels to the bladder.

  • Nephrons in kidneys remove wastes while maintaining necessary water and salt levels. Podocytes are special cells in nephrons that assist in this filtration process.

Skin

  • Sweat glands in skin release sweat containing toxins such as urea, aiding excretion.

How Body Systems Interact

Learning Intention

  • Describe how components of each body system interact for efficient functioning.

Blood as a Common Transport System

  • Circulatory System Connections:

    • Digestive System: Nutrients absorbed enter the blood.

    • Respiratory System: Oxygen enters the blood and is transported.

    • Excretory System: Transports waste products to lungs and kidneys for removal.

Disease and Disorder in the Body

Learning Intention

  • Explain how a disease or disorder in one body system affects the whole body.

Sickle Cell Anemia

  • A genetic disorder affecting red blood cells, resulting in sickle-shaped cells that block blood flow, leading to pain and organ damage.

    • Impacts Circulatory, Respiratory, Immune, Skeletal systems, and Skin.

Plant Systems

Introduction to Plant Systems

Learning Intention

  • Determine the role, structure, and function of components within flowering plants.

Specialised Structures in Flowering Plants

  • Root system, stem, leaves, and flower.

The Roots

Functions

  • Structural support and anchoring of plants.

  • Absorption of water and nutrients necessary for photosynthesis.

Specialised Cells

  • Root hair cells: Increase surface area for absorption.

The Stem

Functions

  • Supports plant structure and transports water, nutrients (via Xylem), and sugars (via Phloem).

The Leaves

Functions

  • Main site of photosynthesis, containing chloroplasts that use sunlight, CO2, and water to produce glucose and oxygen.

  • Responsible for gas exchange through stomata, regulated by guard cells.

The Anatomy of a Flower

Components

  • Flowers are reproductive structures producing gametes for fertilisation and seed development.

Pollination, Fertilisation, and Germination

Process

  • Pollination: Transfer of pollen from anther to stigma, often assisted by pollinators.

  • Fertilisation: A pollen tube grows to the ovary, fertilising the ovule.

  • Germination: Requires water, warmth, and oxygen for seeds to sprout and grow.

Ecosystems

Abiotic and Biotic Factors

Learning Intention

  • Identify components of ecosystems and their interactions.

Ecosystem Definition

  • Ecosystems consist of communities of organisms and abiotic components (climate, minerals).

Influencing Factors

  • Biotic Factors: Living components (plants, animals).

  • Abiotic Factors: Non-living components (water, temperature).

Symbiosis

Learning Intention

  • Identify different symbiotic relationships in ecosystems:

    • Mutualism: Both organisms benefit (e.g., cleaner shrimp and fish).

    • Commensalism: One benefits, the other is unaffected (e.g., barnacles on whales).

    • Parasitism: One benefits, the other is harmed (e.g., tick feeding on a dog).

Matter Cycles

Learning Intention

  • Outline cycles of matter, specifically nitrogen and carbon-oxygen cycles.

Cycling of Matter

  • Nitrogen Cycle: Involves fixation, decomposition, assimilation, and denitrification, essential for proteins and DNA.

    • Nitrogen Fixation, Decomposition, Assimilation, Denitrification.

  • Carbon-Oxygen Cycle: Critical for energy flow; includes processes like photosynthesis, respiration, decomposition.

Food Chains and Food Webs

Learning Intention

  • Understand energy flow through ecosystems.

Food Chains

  • Illustrate energy transfer from producers to various consumer levels.

  • Identify roles:

    • Producers (plants), Primary Consumers (herbivores), Secondary Consumers (carnivores), Tertiary Consumers (top predators).

Food Webs

  • Represent interconnected food chains showing various energy connections in ecosystems.

Energy Pyramids

Learning Intention

  • Construct and interpret energy pyramids in ecosystems.

Energy Flow

  • Illustrates decreasing energy transfer across trophic levels, with only about 10% of energy passing to the next level.

Introduced Species

Learning Intention

  • Explain impacts of non-native species on ecosystems.

Consequences of Introduced Species

  • Loss of biodiversity, disruption of food webs, altered energy flow.

  • Example: Cane toads in Australia disrupting local ecosystems.

Living Systems in Context

Endangered and Extinct Species

Learning Intention

  • Identify factors leading to endangerment and extinction.

Overview

  • Human actions accelerate species decline, leading to high extinction rates in Australia due to:

    • Habitat loss, overexploitation, competition from introduced species, climate change, pollution.

Case Study: Tasmanian Tiger

  • Factors of extinction include hunting, habitat loss, and disease, disrupting food webs and ecosystems.