Biology • Year 11 • Module 2 • Lesson 4
Organs, Organ Systems and Hierarchical Organisation
Lock in the six-level biological hierarchy, the organ/tissue distinction, emergent properties, and the cardiovascular case study.
1. Order the biological hierarchy
The six levels of biological organisation are listed below in scrambled order. Write each level in the correct position in the table, from simplest (Level 1) to most complex (Level 6). Then add one named example for each level from a human or plant. 12 marks
Scrambled levels: Organism • Tissue • Organ • Cell • Organelle • Organ system
| Level | Name of level | Named example (human or plant) |
|---|---|---|
| 1 (simplest) | ||
| 2 | ||
| 3 | ||
| 4 | ||
| 5 | ||
| 6 (most complex) |
2. Term–definition match
The eight definitions below are shuffled. In the right-hand column write the matching term from this list: organ, organ system, hierarchy, emergent property, cardiovascular system, tissue integration, tissue, cardiomyocyte. 8 marks
| # | Definition (shuffled) | Matching term |
|---|---|---|
| 2.1 | A group of similar cells working together to perform a shared function. | |
| 2.2 | A structure composed of two or more tissue types working together to perform a specific function. | |
| 2.3 | A group of organs that cooperate to carry out a major physiological function for the whole organism. | |
| 2.4 | The arrangement of biological organisation into successive levels of increasing complexity, from organelle to organism. | |
| 2.5 | A capability that arises at a given level of organisation that did not exist at the level below it. | |
| 2.6 | The organ system consisting of the heart, blood vessels and blood that transports materials throughout the body. | |
| 2.7 | The combination of two or more different tissue types within an organ to enable complex, multi-step functions. | |
| 2.8 | A specialised heart muscle cell whose organelles include mitochondria for ATP production and myofilaments for contraction. |
3. Organ or tissue? Classification with justification
For each structure below, circle the correct classification, then write one sentence justifying your answer. For organs, name at least two tissue types present. 10 marks
3.1 Tendon Tissue / Organ / Organ system
Justification:
3.2 Stomach Tissue / Organ / Organ system
Justification:
3.3 Cardiac muscle tissue Tissue / Organ / Organ system
Justification:
3.4 Knee joint Tissue / Organ / Organ system
Justification:
3.5 Digestive system Tissue / Organ / Organ system
Justification:
4. Complete the cardiovascular hierarchy table
Fill in the missing cells for the cardiovascular case study introduced in Card 4. Each row moves one level up the hierarchy. 8 marks
| Level | Named component | What this level enables that the level below cannot |
|---|---|---|
| Organelle | Mitochondria; myofilaments | |
| Cell | Cardiomyocyte | |
| Tissue | Synchronised, amplified contraction via intercalated discs, force no single cell can produce | |
| Organ | Heart | |
| Organ system | Whole-body circulation, delivery of O2, nutrients and hormones to every cell |
5. True or false, with correction
For each statement, circle T or F. If the statement is false, write the corrected version. 8 marks
5.1 An organ is simply a larger version of a tissue, containing only one tissue type. T / F
5.2 The heart is an organ because it contains cardiac muscle, epithelial, connective and nervous tissue types working together. T / F
5.3 Emergent properties can be explained by examining any one of the components at a lower level of the hierarchy. T / F
5.4 Homeostasis in a complex organism requires only one organ system to function. T / F
6. Build a concept map
Draw labelled arrows between the six terms below to show how they connect. Each arrow must carry a linking phrase (e.g. “are organised into”, “combine to form”, “enables”). Aim for at least 6 labelled arrows. 6 marks
Supplied terms: organelle • cell • tissue • organ • organ system • emergent property
Q1, Correct order and examples
Level 1, Organelle (e.g. mitochondrion, nucleus, chloroplast, ribosome) • Level 2, Cell (e.g. red blood cell, muscle cell, palisade mesophyll cell) • Level 3, Tissue (e.g. cardiac muscle tissue, epithelial tissue, xylem) • Level 4, Organ (e.g. heart, liver, leaf) • Level 5, Organ system (e.g. cardiovascular system, digestive system) • Level 6, Organism (e.g. human, eucalyptus tree). Award 1 mark per correct level name; 1 mark per biologically valid example (max 12).
Q2, Term–definition matches
2.1 tissue • 2.2 organ • 2.3 organ system • 2.4 hierarchy • 2.5 emergent property • 2.6 cardiovascular system • 2.7 tissue integration • 2.8 cardiomyocyte.
Q3, Organ or tissue? Classifications and justifications
3.1 Tissue. A tendon contains only one tissue type, dense connective tissue with parallel collagen fibres, so it does not meet the definition of an organ (which requires two or more tissue types).
3.2 Organ. The stomach contains smooth muscle tissue (churning), epithelial tissue (protection and secretion of gastric acid), connective tissue (structural support) and nervous tissue (coordination of contractions), multiple tissue types working together.
3.3 Tissue. Cardiac muscle tissue consists of a single cell type (cardiomyocytes) all performing the same contractile function; it does not integrate other tissue types within it.
3.4 Organ. The knee joint integrates articular cartilage (connective tissue), synovial membrane (epithelial tissue), ligaments (connective tissue) and nervous tissue (sensory nerve endings), at least two tissue types, therefore an organ.
3.5 Organ system. The digestive system consists of multiple organs (mouth, oesophagus, stomach, small intestine, large intestine, liver, pancreas) all cooperating to digest food and absorb nutrients.
Marking criteria. 1 mark for correct classification; 1 mark for justification referencing the structural criterion (tissue type count). 2 marks per item, 5 items = 10 marks.
Q4, Cardiovascular hierarchy table
Organelle, what it enables: Mitochondria produce ATP for energy; myofilaments use ATP to generate mechanical force, individual biochemical reactions compartmentalised.
Cell, what it enables: Integrates mitochondria and myofilaments into a self-contained contractile unit capable of coordinated contraction and electrical communication via intercalated discs.
Tissue, named component: Cardiac muscle tissue (cardiomyocytes).
Organ, what it enables: Directed, rhythmic pumping, the integration of cardiac muscle (force), epithelium (chamber lining), connective tissue (valves) and nervous tissue (SA node pacemaker) creates a self-regulating pump that generates pressure and directs one-way blood flow.
Organ system, named component: Cardiovascular system (heart + arteries + capillaries + veins + blood).
Marking criteria. 1 mark per missing cell correctly completed. Missing cells: Organelle “what it enables” (1), Cell “what it enables” (1), Tissue “named component” (1 mark, must name cardiac muscle tissue), Organ “what it enables” (1–2 marks, accept reference to pumping/valves/pacemaker), Organ system “named component” (1 mark). Award up to 8 marks total.
Q5, True / false with corrections
5.1 False. Correction: An organ contains two or more tissue types working together, this is what fundamentally distinguishes it from a tissue (which contains only one tissue type).
5.2 True.
5.3 False. Correction: Emergent properties arise from organisation across levels, not from any single component at a lower level. No single mitochondrion, myofilament or cardiomyocyte explains how the heart pumps blood.
5.4 False. Correction: Homeostasis requires the simultaneous coordination of multiple organ systems (nervous, endocrine, cardiovascular, excretory and others). No single system can regulate blood glucose, temperature, pH and blood pressure at the same time.
Q6, Sample concept map
A correct map should include arrows such as:
- organelleare enclosed within → cell
- cellgroups of similar cells combine to form → tissue
- tissuetwo or more tissue types integrate to form → organ
- organcooperating organs form → organ system
- organarises at this level because of integration → emergent property
- emergent propertyjustifies the existence of each higher → organ system
Any biologically valid linking phrases are accepted. Award 1 mark per correctly labelled, causally directed arrow (max 6).