Teachers are reminded, prior to reading this section, that the syllabus is the definitive prescribed material.
It is hoped that this section will help promote professional teaching methods as distinct from textbook methodology. This section could be used as a class guide through the syllabus. It is not intended to be a text for students as it contains both non-prescribed and prescribed material.
To assist and support you in class preparation:
- The preamble to each subunit gives a broad insight into the central ideas of the syllabus depth of treatment.
- The suggested `texted' and practical detail should be used as suggestions to support you in:
Depth of prescribed and non-prescribed material you wish to use.
Methodology practice to include practical activities.
Suggested resources.
Time parameters.
Special attention in class preparation should be given to the use of 22 class periods for non-prescriptive material at Ordinary level.
You may wish to use the non-prescribed activities and resources marked by an asterisk * or use other materials such as DART.
PREAMBLE TO SUB-UNIT 3.1: DIVERSITY OF ORGANISMS
- We share this planet with a variety of organisms which are classified in five kingdoms: Monera (Prokaryotae), Protista (Protoctista), Fungi, Plant and Animal.
- From the origin of the prokaryotic Monera, the eukaryotic Protista, Fungi, Plants and Animals have developed functional multicellular organisation.
- Micro-organisms may be beneficial or harmful and must be handled with care.
- Beneficial use is made today of micro-organisms, this requires detailed understanding of their life characteristics and how they function.
- Safety precautions should be rigidly observed in all microbiological activities.
MANDATORY ACTIVITIES
LABORATORY INVESTIGATIONS
Students should:
- Investigate the growth of leaf yeast using agar plates and controls.
Students may refer to 2.2.5:
- Prepare and show the production of alcohol by yeast.
3.1 DIVERSITY OF ORGANISMS / SUGGESTED CLASS PERIODS: 14 OL, 17 HL
3.1.1 DIVERSITY OF ORGANISMS
DEPTH OF TREATMENT
General introduction to microbial life and the five kingdom system of classficiation Monera (Prokaryotae), Protista (Protoctista), Fungi, Plant and Animal. (Further sub-classification not required).
ACTIVITIES
*Classify a number of organisms from each kingdom.
SUGGESTED RESOURCES
Microscopes
Prepared slides or acetates
3.1.2 MICRO-ORGANISMS
DEPTH OF TREATMENT
Distribution of bacteria and fungi in nature salt water, fresh water, terrestrial, air-borne.
3.1.3 MONERA, e.g. BACTERIA
DEPTH OF TREATMENT
Basic structure to include: cell wall, cell membrane, genomic material including plasmid, cytoplasm, flagella, capsule.
Three main types of shapes: cocci, spirals, rods.
Reproduction asexual by binary fission.
Binary Fission: DNA replicates
- cell elongates pushing the replicated DNA apart
- ingrowths of cell membranes (and cell walls) occur forming two identical cells or organisms.
Because of their short life cycles and multiple generations, mutation becomes a very important feature.
Endospore formation: formed in unfavourable environments.
Here the cell shrinks, rounds up and forms a thick wall within the original structure.
When conditions are favourable, the spores absorb water, break their walls and reproduce by binary fission.
Nutrition -- definition and examples of:
autotrophic - photosynthetic and chemosynthetic
heterotrophic saprophytic and parasitic.
Factors affecting growth:
temperature, oxygen concentration, pH, external solute concentrations, and pressure.
Beneficial and harmful micro-organisms. Understanding of the term "pathogenic".
Definition and role of "antibiotics". Need to refer to antibiotic resistance and competition between sensitive and resistant strains.
Contemporary Issues & Technology
Economic importance of bacteria: examples of any two beneficial and any two harmful bacteria.
Potential abuse of antibiotics in medicine.
3.1.4 FUNGI
DEPTH OF TREATMENT
Saprophytic and parasitic forms.
Rhizopus
Structure to include:
hyphae and mycelium
rhizoids
sporangiophores
stolon
apophysis
columella
sporangium
spores
Reproduction and life cycle:
Asexual reproduction -- sporulation.
Some hyphae grow upwards and form a sporangium. The stalk of the sporangium is called a sporangiophore. Within the sporangium mitotic division occurs to produce a mass of cells. Penetration hyphae at the base of the sporangiophore are called rhizoids.
Each cell develops a resistant wall now to be called a spore. If, when spores are dispersed by wind, they fall on a suitable substrate, they begin to germinate and give rise to new mycelia.
Sexual reproduction --
production of progametangia
formation of gametangia and suspensors
zygospore formation
germination of zygospore.
Mode of nutrition.
Yeast
Structure: unicellular nature, cell wall, nucleus, granular cytoplasm, vacuoles.
Reproduction by budding:
a small extension (bud) is formed on the cell this bud enlarges and is filled with cytoplasm the nucleus of the parent cell divides by mitosis one of the nuclei formed moves into the bud which may remain attached to the parent and undergo further budding to form a colony or break free of the parent and form a new colony itself.
Contemporary Issues & Technology
Edible and poisonous fungi:knowledge, methods of distinctionand examples.
Contemporary Issues & Technology
Economic importance of fungi:examples of any two beneficial and any twoharmful fungi.
3.1.5 LABORATORY PROCEDURES WHEN HANDLING MICRO-ORGANISMS
DEPTH OF TREATMENT
Precautions when working with micro-organisms: assume that all are hazardous until otherwise proven.
Definition of the terms:
"asepsis"and "sterility" as applied to living organisms.
Sterilisation of working area, all equipment, instruments and materials before and after use.
Flaming of containers and loops during use.
Containment methods and safe disposal of unwanted materials after use.
3.1.6 PROTISTA, e.g. AMOEBA
DEPTH OF TREATMENT
Amoeba cell organisation to include nucleus and sub-cellular structures.
Contemporary Issues & Technology
*Mention of amoeboid diseases.
3.1.7 PLANT, e.g. THE FLOWERING PLANT
DEPTH OF TREATMENT
Plant kingdom as exemplified by the flowering plant. (Refer to the remaining sub-units of Unit Three).
3.1.8 ANIMAL, e.g. THE HUMAN
DEPTH OF TREATMENT
Animal kingdom as exemplified by the human. (Refer to the remaining sub-units of Unit Three).
ACTIVITIES
*Prepare nutrient agar plates for inoculation.
Investigate the growth of leaf yeast using agar plates and controls.
SUGGESTED RESOURCES
Petri dishes, Nutrient agar, Autoclave or pressure cooker, Alcohol, Aseptic wash solutions, Parafilm, Glassware, Prepared nutrient agar plates, Autoclave or pressure cooker, Oven, Alcohol, Inoculating loops, Heat source, Aseptic wash solutions, Leaf yeast source, Parafilm, Forceps.
HIGHER LEVEL EXTENSION
H.3.1.9 NATURE OF BACTERIA AND FUNGI
DEPTH OF TREATMENT
Prokaryotic nature of bacteria. Eukaryotic nature of fungi.
H.3.1.10 GROWTH CURVES
DEPTH OF TREATMENT
Plot a growth curve to include five phases lag, log, stationary, decline/death, survival. Explanation of microbial behaviour in each stage.
Contemporary Issues & Technology
Batch and continuous flow food processing. Batch organisms in a five phase growth curve.Continuous organisms maintained in a particular growth phase.
PREAMBLE TO SUB-UNIT 3.2: ORGANISATION AND THE VASCULAR STRUCTURES
In Unit One organisation was classified as a `characteristic of life'.
In Unit Two cellular organisation was examined in depth.
In this sub-unit we examine, with functional emphasis, organisation in organisms with special reference to the vascular system.
- From the origin of the prokaryotic Monera and the eukaryotic Protista, Fungi, Plants and Animals have developed functional multicellular organisation.
- Multicellular organisation involves tissues, organs, organ systems, individual organisms and populations.
- Structural organisation relates to the functions necessary for metabolism and continuity.
Higher Level Extension - A more detailed knowledge and understanding of specific functions of the vascular system in the human should be developed.
MANDATORY ACTIVITIES
MICROSCOPY, DISSECTION AND LABORATORY INVESTIGATION
Students should:
- Prepare and examine microscopically the transverse section of a dicotyledonous stem (×100, ×400).
- Dissect, display and identify the parts of an ox's or a sheep's heart.
- Investigate the effect of exercise on the breathing rate or pulse rate of a human.
3.2 ORGANISATION AND THE VASCULAR STRUCTURES / SUGGESTED CLASS PERIODS: 21 OL, 24 HL
DEPTH OF TREATMENT
Organisational complexity of the flowering plant as exemplified by the root, stem, leaf, flower, seed, and transport (vascular) structures.
Division into two portions root system and shoot system. Describe the structures and function of each portion to include all outer stem parts and root zonations.
Explain the term "meristem". Identify its location in the shoot and root apices.
Meristematic tissue divides to produce new cells in-situ, differentiation of which leads to:
dermal tissue -- forms the protective covering of plants
ground tissue -- fills the interior
vascular (transport) tissue -- conducts water and nutrients in a plant.
Location of three tissue types dermal, ground and vascular in transverse sections of the root, stem and leaf and in longitudinal sections of the root and stem.
Xylem and phloem form the two vascular tissues in angiosperms.
Describe each of their functions.
Draw and identify each tissue type.
Distinguish between xylem tracheid cells and xylem vessel cells, phloem sieve tube cells and companion cells.
Identification of dicotyledons (dicots): may be woody or herbaceous, have flower parts usually in units of fours and fives, have net leaf veins, have vascular bundles localised in an orderly array, which may be circular or opposite in the stem, have two cotyledons or seed leaves.
Identification of monocotyledons (monocots): are almost always herbaceous, have flower parts usually in units of threes, have parallel leaf veins, have scattered vascular bundles in the stem, have one cotyledon or seed leaf.
ACTIVITIES
*From a supply of plants, identify the root and shoot systems - locate the meristematic regions.
*Draw and identify the position of each of these tissue types dermal, ground and vascular in transverse and longitudinal sections of the root, stem and leaf.
*Using prepared slides microscopically examine longitudinal view of xylem tracheid and xylem vessel cells, phloem sieve tube and companion cells.
Prepare and examine microscopically the transverse section (T.S.) of a dicotyledonous stem.
*Examine and identify monocot. and dicot. leaves and seeds from a variety of plants.
SUGGESTED RESOURCES
Variety of plant material, Microscopes (or bioviewers), prepared slides, Microscopes, glass slides, cover slips, forceps, scalpels or backed blades, dissecting boards, petri dishes, filter paper, variety of plant material
3.2.2 ORGANISATIONAL COMPLEXITY OF THE HUMAN
DEPTH OF TREATMENT
Organisational complexity of animals as exemplified by the circulatory structures of the human system by brief reference to the efficiency of a closed circulatory system in humans.
Describe the structures and organisation of tissues in the closed circulatory system in humans.
The strong muscular heart in which the atria receive blood and the muscular ventricles pump the blood through the vessels.
Vessels of the human circulatory system. Draw, label and give the functions of the artery, vein and capillary. Refer to the existence and position of arterioles and venules the role of muscle tissue and valves in the heart and circulatory tissues.
The existence of a two-circuit circulatory system in humans:
the pulmonary, pumping blood from the heart to the lung tissues and back.
the systemic, pumping blood from the heart to the remaining body tissues and back.
Draw the structure of the heart and the main pathways of blood circulation through the pulmonary and systemic pathways. Include the portal system one that begins and ends in capillaries e.g. the hepatic portal vein.
As a living organ of the body the heart has its own blood supply through the coronary arteries and cardiac veins.
ACTIVITIES
*Use models or charts to highlight the heart, arteries, arterioles, capillaries, venules and veins in the human.
*Microscopic examination of an artery (T.S.) and a vein (T.S.).
Following the dissection of an ox's heart and attached vessels by the teacher, students should dissect an ox's or a sheep's heart and attached vessels in order to learn the skills of dissection and reinforce their knowledge of the heart structure by practical observation, labelling and drawing.
Investigate the effect of exercise on the breathing or pulse rate of a human.
*Microscopic examination of prepared blood smear to identify the different blood cell types and platelets.
SUGGESTED RESOURCES
Models of heart and circulatory system. Microscope, slides, scalpels, cover slips, boards, material for T.S. Fresh ox/sheep hearts Dissecting kits Dissecting boards/ Dissecting trays Coats or aprons Pins and flag labels Washing facilities. Data logging, ICT
Set of leaflets from the Health Education Bureau and Irish Heart Foundation etc.
Microscopes Prepared slides or bioviewers and slides.
Contemporary Issues & Technology
Knowledge of the effects of smoking, diet and exercise on the circulatory system.
Simple understanding of the following:
Heartbeat and its control: heartbeat is controlled by the pacemaker, situated in the right atrial wall. It initiates a wave of muscular contraction through the heart from atria to ventricles. The heartbeat sound is caused by the closing of valves in the heart.
Pulse: a wave of vibrations that passes down the walls of arteries when the aorta expands following a ventricular contraction.
Blood pressure: blood is forced into arteries under pressure from the left ventricle, the region of highest pressure, eventually reaching the right atrium, the region of lowest pressure. As it passes from arteries to arterioles to capillaries to venules and to veins the pressure decreases. Human blood pressure is taken normally for reference from an artery of the upper arm it measures the amount of pressure required to stop the flow of blood through this artery.
The lymphatic system:the lymphatic system is a one way system of vessels that returns excess tissue fluid to the blood circulatory system. The lymph nodes assist in fighting infection in the body. Description of any three functions of the lymphatic system is sufficient.
Composition of blood, roleof red blood cells, whiteblood cells, platelets andplasma: (classification of white blood cells not required).
Blood grouping: names of the common blood groups A, B, AB, O and the Rhesus factor.
HIGHER LEVEL EXTENSION
H.3.2.3 BLOOD CELLS (EXTENDED STUDY)
DEPTH OF TREATMENT
More detailed treatment of red blood cells e.g. absence of nucleus, absence of mitochondria, affinity for oxygen. White blood cell classification as lymphocytes and monocytes.
H.3.2.4 HEARTBEAT CONTROL
DEPTH OF TREATMENT
Heartbeat control
An awareness of:
specialised heart muscle tissue
the existence and location of pacemaker nodes
the SA (sinoatrial) node
the AV (atrioventricular) node.
The heart cycle
The functioning of the SA and AV nodes in relation to systole and diastole periods in the heart cycle.
PREAMBLE TO SUB-UNIT 3.3: TRANSPORT AND NUTRITION
- Plants are autotrophic and require the transport of water, carbon dioxide, oxygen and certain minerals for metabolism, growth and reproduction. This sub-unit examines how plants acquire and transport these substances to the site of photosynthesis and the distribution of photosynthetic products.
- Leaf organisation in relation to its photosynthetic function.
- Modification of leaves, stems and roots as food storage organs.
- Animals are heterotrophic and must absorb preformed food. The variety of adaptations by animals to this function varies greatly. This sub-unit specifically examines the acquisition and transport of nutrients in humans.
- The concept of a balanced diet.
Higher Level Extension: - The cohesion tension model of xylem transport.
MANDATORY ACTIVITIES
LABORATORY SKILLS
Students may refer to 2.2.6: Conduct any activity to demonstrate osmosis.
3.3 TRANSPORT AND NUTRITION / SUGGESTED CLASS PERIODS: 15 OL, 16 HL
3.3.1 NUTRITION IN THE FLOWERING PLANT
DEPTH OF TREATMENT
Plants are autotrophic and require the transport of water, carbon dioxide, oxygen and certain minerals for metabolism (e.g. photosynthesis, respiration), growth and reproduction.
Description of the uptake and transport of the following through the plant:
Water
Water moves into the root hair cells from the soil, by osmosis.
Water diffuses from cell to cell across the ground or cortex tissue until it reaches the vascular tissue the xylem.
Xylem vessels now form the best route for the transport of water to all parts of the plant.
They form a continuous hollow pipeline from roots to leaves.
The transport of water up through the xylem is helped by root pressure generated by water entering the root cells by osmosis which pushes the water up the xylem.
When water evaporates from the cells in the leaf (transpiration), the cells become less turgid. This creates an osmotic gradient that causes the water to move from the xylem cells out to these cells.
The loss of water from the leaves is controlled by a waxy cuticle and by the opening and closing of the stomata.
Minerals
Minerals dissolved in water are transported from the roots to all parts of the plant by the same route as water.
Carbon dioxide
Carbon dioxide can be obtained directly from respiring cells or enter the leaves through open stomata.
Photosynthetic products
Within the primary photosynthetic organ of the plant, the leaf, the photosynthetic process occurs in chlorophyll containing cells. The product is stored as starch or transported from the leaves to other plant cells through phloem sieve tube cells.
ACTIVITIES
Carry out an experiment to demonstrate osmosis using an artificial cell or living material (as in Unit Two, sub-unit Two).
*Demonstrate the pathway of water in plants using dye experiments.
*Demonstrate the use of the potometer and atmometer to investigate the rate of transpiration.
SUGGESTED RESOURCES
Visking tubing, glucose solution, iodine solution**, Plant stem, leaf or flower, food dye, Leafy shoot, potometer, atmometer, vaseline, ICT
3.3.2 MODIFIED PLANT FOOD STORAGE ORGANS
DEPTH OF TREATMENT
One example of a root, stem and leaf modification as a food storage organ should be examined.
Root modification
In some plants e.g. dicots, the first root grows straight down to form the main root of the plant. This root may become fleshy and modified to store food.
Stem modification
Modified swollen terminal bud or modified stems called tubers that function in the storage of food e.g. potatoes.
Modified leaves
Leaves can be modified for food storage e.g. onion bulbs, celery or rhubarb leaf petioles.
3.3.3 NUTRITION IN THE HUMAN
DEPTH OF TREATMENT
Animals are heterotrophic organisms that must take in preformed food. Whilst humans and some other animals are omnivores most animals are either herbivores or carnivores. Simple definition of each of these terms.
Explain the term "digestion". Outline the need for digestion and a digestive system.
Explain the terms "ingestion", "digestion", "absorption" and "egestion" as related to the sequence in the human digestive tract.
ACTIVITIES
*Microscopically examine the transverse section of a leaf. Draw and label its cell parts.
SUGGESTED RESOURCES
Microscopes, slides, cover slips, scalpels or backed blades, dissecting boards, petri dishes, filter paper.
ACTIVITIES
*Examine a selection of modified roots, stems and leaves.
RESOURCES REQUIRED
Selection of modified roots, stems and leaves.
3.3.4 HUMAN DIGESTIVE SYSTEM
DEPTH OF TREATMENT
Macrostructure and basic function of the alimentary canal and associated glands in digestion and transport of nutrients.
Explanation of the mechanical breakdown and transport of food, to include the role of teeth (dental formula for humans only), the term peristalsis and a description of its effects, the contractions of the stomach and how they help in the breakdown of food.
Explanation of the chemical breakdown of food, to include:
- bile salts
- the role, production site, pH at a named location of action, and products of an amylase, a protease and a lipase enzyme.
Refer to the presence and two functions of symbiotic bacteria in the digestive tract.
Outline the benefits of dietary fibre.
Explain how the structure of the small intestine is related to its function (villi and associated structures digestion, absorption and transport of food).
Describe the role of the large intestine in water absorption and elimination of faeces.
3.3.5 BLOOD TRANSPORT OF NUTRIENTS
DEPTH OF TREATMENT
Describe the composition of blood fluid as a transport system of nutrients in the human body.
Describe the absorption of the nutrients in the digestive tract into the blood vessels and lacteals of the villi.
Transfer of nutrients from the villi through the hepatic portal vein to the liver.
Describe the functions of the liver (without detailed biochemical pathways) in list format.
The transport of nutrients from the liver to all nutrient-requiring cells of the body.
The transport of waste products to the kidney for filtration and excretion.
Contemporary Issues & Technology
* Medical disorders of the digestive system.
* Brief note (one paragraph each in essay format) of the symptoms, cause and prevention of thefollowing: dental decay / stomach ulcers / appendicitis / dietary any one vitamin or one mineral deficiency/slimming disorders.
ACTIVITIES
*In order to highlight the characteristic teeth of herbivores, carnivores and omnivores examine various representative skulls.
*Use a model display of the human alimentary canal to identify its main parts.
*Examine a prepared section of the small intestine using prepared slides, transparencies or other suitable visual aids to gain a general understanding of its structure in relation to its function. Detailed histology not required.
*Examine a prepared blood smear slide to determine the composition of blood fluid. (Students should not use fresh blood samples).
*Note the size and position of the liver in a model of the human system.
*Write an essay on medical disorders as outlined.
SUGGESTED RESOURCES
Various skulls of herbivores, carnivores and omnivores. Model of human alimentary canal. Microscopes, prepared slides of the small intestine, Microscopes, prepared blood slides, Model of the human system. Portfolio file.
3.3.6 BALANCED HUMAN DIET
DEPTH OF TREATMENT
Explain the concept of a balanced diet, variety and moderation.
Relate its importance to age, sex and activity -- simple treatment only.
Variety from food groups
milk and milk products meat, fish and poultry breads and cereals fruit and vegetables others e.g. fats, oils, alcohol.
Refer to the food pyramid.
HIGHER LEVEL EXTENSION
H.3.3.7 COHESION-TENSION MODEL OF XYLEM TRANSPORT
DEPTH OF TREATMENT
The cohesion tension model explains how water is transported in plants to extreme heights against the force of gravity.
It relates to:
- the attractive forces between water molecules
- the ability of these forces to hold water molecules in a column without breaking when a tension is applied (cohesive property)
- transpiration that causes this tension
- how tension can pull a column of water of very small diameter up to great heights in xylem vessels.
Refer to the work of Dixon and Joly.
PREAMBLE TO SUB-UNIT 3.4: BREATHING SYSTEM AND EXCRETION
- All organisms have the ability to maintain constant conditions in their cells and bodies such as temperature, fluid balance and chemistry. This is achieved by homeostasis e.g. by diffusion, by developing exchange systems which include the respiratory and excretory systems.
- In all organisms adequate amounts of gases, nutrients and toxic wastes are exchanged by diffusion between cells and their environment. The efficiency of exchange is proportional to the surface area over which diffusion can take place.
- In large organisms, such as plants and animals, the problem of size in relation to diffusion and exchange have been overcome by various means such as:
(a) the body may be flattened, thus reducing the distance between the two surfaces e.g. the leaves of plants.
(b) increasing the surface area e.g. alveoli in the respiratory system.
(c) the body may develop systems where the material is brought to the body surface e.g. by respiratory and excretory systems. - Because diffusion can only effectively distribute materials over a short distance, about 0.5 mm, large active animals such as humans also require a circulatory system to help in the transport of gaseous materials and toxic waste.
- Following an understanding of the role of the breathing and excretory systems, students should understand the structures and functioning of these systems.
Higher Level Extension - Controlling factors in gaseous exchange and excretory functions.
MANDATORY ACTIVITY
LABORATORY INVESTIGATION
Students may refer to 3.2.2: Investigate the effect of exercise on the breathing rate or pulse rate of a human.
3.4 BREATHING SYSTEM & EXCRETION / SUGGESTED CLASS PERIODS: 12 OL, 14 HL
3.4.1 HOMEOSTASIS
DEPTH OF TREATMENT
Definition of "homeostasis".
3.4.2 NECESSITY FOR HOMEOSTASIS
DEPTH OF TREATMENT
Necessity to maintain constant conditions in the cells and bodies of living organisms such as temperature, fluid balance and chemistry.
3.4.3 THE STRUCTURE OF AN EXCHANGE SYSTEM IN FLOWERING PLANTS
DEPTH OF TREATMENT
Examination of the structure of a leaf in relation to gaseous exchange of oxygen and carbon dioxide through the stomata. Mention the role of lenticels in stem structure.
ACTIVITIES
*Examine microscopically a T.S. of a leaf blade. Note the intercellular air spaces allowing free diffusion of carbon dioxide and oxygen.
*Examine stomata distribution on a leaf blade.
SUGGESTED RESOURCES
Microscopes, Leaf blades, Backed blades, Raw potato, Glass slides, Cover slips, Sellotape
3.4.4. THE BREATHING SYSTEM IN THE HUMAN
DEPTH OF TREATMENT
Macrostructure and basic function of the breathing tract in humans. (Nasal and buccal cavities, pharynx, epiglottis, glottis, larynx, trachea, bronchi, bronchioles, alveoli).
Essential features of the alveoli and capillaries as surfaces through which gaseous exchange takes place.
Describe the mechanism of the breathing system in the exchange of gases to include:
- the role of the diaphragm, the intercostal muscles and brain (exclude C02 levels) in breathing
- pressure changes in the thoracic cavity
- gaseous exchange in alveoli
- role of haemoglobin in oxygen transport
- source of carbon dioxide from the plasma
- water vapour exhalation.
Contemporary Issues & Technology
Breathing disorders: one example from the following:
Asthma or bronchitis
One possible cause -- triggering agents e.g. pollen, dog andcat dander, house mites, infections, drugs, vigorousexercise and psychological stress.
Prevention, treatment e.g. use of inhalers.
ACTIVITIES
*Use models or charts to highlight the main parts of the respiratory system in humans.
*Demonstrate the mechanism of breathing using the "Artificial Lung Experiment".
*Students may carry out the breathing exchange experiment using limewater or bicarbonate indicator. Experiment to show the effect of exercise on the breathing rate.
*By a series of acetates compare healthy lungs with lungs of unhealthy respiratory systems.
*Demonstrate the effect of cigarette smoke using cotton wool, bicarbonate indicator etc.
SUGGESTED RESOURCES
Model of respiratory system in the human, Bell jar and artificial lung attachments, Large test tubes, Rubber tubing, Clips, Double-holed stoppers Limewater or bicarbonate solution, Apparatus to measure breathing rate. Data logging, ICT, Leaflets from the Asthma Society of Ireland and the Health Education Bureau, Department of Health. Acetates and overhead projector.
3.4.5 PLANT EXCRETION
DEPTH OF TREATMENT
Examine the role of leaves and lenticels as excretory organs of plants. Students should appreciate however that excretion is an animal function and that secretion or loss from plant would be more appropriate.
ACTIVITIES
*Conduct experiments to show that plants lose gases through the stomata of leaves.
SUGGESTED RESOURCES
Limewater or bicarbonate indicator Test tubes or conical flasks, Corks, potted plants, light source, vaseline
3.4.6 THE EXCRETORY SYSTEM IN THE HUMAN
DEPTH OF TREATMENT
The role of the excretory system in homeostasis:
a very simple introduction to the role of the excretory system in humans by reference to homeostasis the ability and necessity to maintain constancy of body temperature, fluid balance and chemistry.
Body temperature
Temperature influences the rate of the chemical reactions that sustain life.
Refer to the different methods of temperature regulation in animals.
Ectotherms lose or gain heat by moving into areas where temperature is suitable.
Endotherms source of heat is internal from its own metabolic heat.
Temperature regulation in humans
Refer to piloerection, vasoconstriction and brain initiated increased metabolic rate as responses to cold conditions.
Refer to perspiration as a response to warm conditions. Include the evaporation of sweat, position of sweat glands in the skin, components of sweat and the necessity to drink water before, during and after exercising to maintain the balance of water and salts in the body.
Fluid balance and chemistry
Macrostructure and basic function of the urinary excretory system in humans (kidneys, ureters, urinary bladder, and urethra).
Role of the kidney in extracting wastes and toxins from the blood and recycling valuable substances by filtration, reabsorption and secretion thus regulating the body fluids and chemistry of the body.
By reference only to the cortex, medulla and renal pelvis identify the positions of filtration, reabsorption and secretion in the kidney.
Describe the pathway of urine from the kidney to the urethra.
Contemporary Issues & Technology
*Unhealthy urinary systems.Paragraph reference to:
bacterial urinary tract infections
formation of kidney stones
renal tubule failure
dialysis
kidney transplants
ACTIVITIES
*Use acetates or videos to refer to different methods of body temperature control in animals, include the human.
*Use photographs or acetates or model to show T.S. of human skin.
*Examine model or chart display of excretory system of the human.
*Write an essay report on "Unhealthy Urinary Systems".
SUGGESTED RESOURCES
Acetates and overhead projector, Video, Acetates and overhead projector T.S. of human skin, Model or display chart of human excretory system. Portfolio
HIGHER LEVEL EXTENSION
H.3.4.7 CARBON DIOXIDE: A CONTROLLING FACTOR IN GASEOUS EXCHANG
DEPTH OF TREATMENT
Carbon dioxide concentration is a controlling factor in stomatal opening and in the human breathing (respiratory) system.
H.3.4.8 THE NEPHRON AS A UNIT OF KIDNEY FUNCTION
DEPTH OF TREATMENT
The nephron structure and its associated blood supply.
Formation of urine
Blood enters the glomerulus under pressure which force-filters the plasma minus proteins and other large molecules into the lumen of the Bowman's capsule.
The glomerular filtrate passes from the Bowman's capsule into the proximal convoluted tubule where reabsorption of substances needed by the body takes place.
Glucose, amino acids, some salts and water are reabsorbed back into the blood by osmosis, diffusion, and active transport.
More water is reabsorbed in the Loop of Henle and the distal convoluted tubule.
The remainder, now called urine, passes into the pelvis of the kidney and to the bladder for storage.
Reabsorption of water in the collecting duct is under hormonal influence (ADH). Its secretion depends on the water content of the blood.
ACTIVITIES
*Examine a nephron structure using photographs, acetates, microslides.*Use video for kidney functions.
SUGGESTED RESOURCES
Acetates or microslides and overhead projector, Video
PREAMBLE TO SUB-UNIT 3.5: RESPONSES TO STIMULI
- Living organisms sense and respond to certain environmental changes, responding in a variety of ways.
- Plants and animals respond in complex ways, for example, by growth and movement.
- Response is a form of defense that allows organisms to survive.
- Some structures of behaviour include:
(a) chemical or hormonal system
(b) nerve and sense organ system
(c) muscular and skeletal systems
(d) an immune system e.g. response to viral infection.
Higher Level Extension - Extended study of response in plants and animals.
MANDATORY ACTIVITY
LABORATORY INVESTIGATION
Students should: Investigate the effect of IAA growth regulator on plant tissue.
3.5 RESPONSES TO STIMULI / SUGGESTED CLASS PERIODS: 32 OL, 37 HL
3.5.1 STRUCTURES FOR RESPONSE
DEPTH OF TREATMENT
Chemical or hormonal system.
Nerve and sense organ systems.
Movement to include growth, muscular and skeletal.
An immune system.
3.5.2 RESPONSES IN THE FLOWERING PLANT
DEPTH OF TREATMENT
Growth regulation
Some external factors that regulate the growth of plants are light intensity, day length, gravity, temperature.
Among the principal internal factors that regulate these responses is the production of a series of chemicals called growth regulators in regions of the plant called meristematic regions. Give examples of some meristematic regions.
Tropisms
Definition of the following tropisms:
"phototropism"
"geotropism"
"thigmotropism"
"hydrotropism"
"chemotropism"
Emphasise the significance of phototropism and geotropism, with examples.
ACTIVITIES
*Draw the external structure of a flowering plant. Highlight and identify meristematic regions.
*Conduct a series of simple experiments to demonstrate phototropism.
SUGGESTED RESOURCES
Plant samples. Plant material, Growing boxes, Light sources
Regulatory system
Definition of growth regulator, transport through the vascular system. Different combinations of regulators bring about different effects.
Some regulators promote growth e.g. auxins.
Others inhibit growth e.g. ethene and abscisic acid.
Describe any four methods by which plants protect themselves from adverse external environments anatomical/chemical e.g. heat shock proteins or stress proteins.
Contemporary Issues & Technology
Use of plant growth regulators: any two examples.Commercial preparation e.g.as rooting powdersin tissue culturingethene in green banana ripening
3.5.3 RESPONSES IN THE HUMAN
DEPTH OF TREATMENT
The nervous system
The division of the human nervous system into two parts the central nervous system (CNS) and the peripheral nervous system (PNS).
Receptor messages are carried through these systems by nerve cells or neurons.
Neuron structure with reference only to cell body, dendrites, axon, myelin sheath, Schwann cells and neurotransmitter vesicles.
The structure and function of a neuron: variation in size and shape.
Three part structure --
dendrite(s) receive information and carry it towards the cell body, the axon conducts nerve impulses away from the cell body, the cell body contains the nucleus and other organelles and produces neurotransmitter chemicals.
ACTIVITIES
*Use acetates to highlight and identify CNS and PNS.
SUGGESTED RESOURCES
Acetates and overhead projector.
ACTIVITIES
*Use acetates to show the variety of effects of plant growth regulators. Investigate the effect of IAA growth regulator on plant tissue.
*Demonstrate the skill of taking plant tissue cuttings and the use of rooting powders to promote growth.
*Examine and identify a number of plant protective measures (use living samples or video)
SUGGESTED RESOURCES
Acetates and overhead projector; Plant material; Hand sprayer; Beaker; Spatula; Mask;IAA; Plant material; Secateurs; Rooting powder; Compost; Flower pot; Visit a habitat; Video
Knowledge that the conduction of nerve impulses along a neuron involves movement of ions (details not required). The region where two neurons come into close contact is called the synapse. Refer to the gap between the neurons as the synaptic cleft.
When neurotransmitters are activated by the ions they are released into the cleft for a very short time, transmitting the impulse to the next neuron.
After transmission, the neurotransmitter is inactivated by an enzyme and reabsorbed by the presynaptic neuron and used to make new neurotransmitter substance.
Three types of neurons - sensory, motor and interneuron:
sensory neurons - carry messages from the sense organ to the CNS motor neurons - carry messages from the CNS to muscle fibres and glands interneurons - carry messages within the CNS.
The sense organs contain receptors.
The brain acts as the interpreting centre for received information.
Knowledge of the five senses and related organs.
Recognition of the main parts of the eye and ear. Single statement of function related to each part.
Corrective measures for long sightedness and short sightedness or for a hearing defect.
Note:The following are not required: biochemical action detailed structure of cochlea and semicircular canals in ear names of sensory receptors in the skin.
Central nervous system: the brain and spinal cord.
Recognition of location and function of the following parts of the brain: cerebrum, hypothalamus, pituitary gland, cerebellum, and medulla oblongata.
ACTIVITIES
*Examine a prepared slide of a neuron, draw and identify its parts.
*Use the drawing of the neuron from the previous activity to highlight the path direction of a nerve impulse with a coloured pencil.
*Draw, from an acetate, a synapse and with a different pencil colour shade in the release of the neurotransmitter across the synaptic cleft, its breakdown using an eraser, and re-absorption. Mention how some drugs inhibit or prolong this effect.
*Simple experiments on taste, smell, touch, temperature and pressure.
*Use of convex or concave lenses as a corrective measure for sight defects
*Study the structure of the ear using charts or models.
*Refer to possible hearing disability as a result of excessive noise levels.
*Use of hearing aids.
* Use model of skin to revise structure as a sense organ.
*Using a model of the brain to show its major parts in relation to function.
SUGGESTED RESOURCES
Microscopes; Prepared slides of neuron or bioviewers; Drawing sheets; Coloured pencils; Different taste solutions Droppers Needles Cold object Warm object Convex and concave lenses Lighted candle Screen Stands
Model of ear. Model of skin. Model of the brain or charts
Cross-section of the spinal cord indicating the following: white matter (containing axons only), grey matter (cell bodies and dendrites), central canal (filled with cerebrospinal fluid) three-layered protective tissue, the meninges (spinal meningitis is an infection of these layers) spinal nerves containing dorsal and ventral roots that project from the spinal cord.
The peripheral nervous system: important to emphasise that the PNS contains nerve fibres structures of long dendrites and/or long axons. There are no cell bodies in nerves as cell bodies are only found in the CNS or in ganglia (collection of cell bodies within the PNS e.g. the dorsal root ganglion).
Role, structure and mechanisms of the reflex arc/action.
Note: Cranial nerves, sympathetic and parasympathetic systems are not required.
The endocrine system
Definition of a "hormone". Refer to the protein nature of many hormones.
Emphasise the general slow and sustained nature of hormone action as compared with nerve action.
Distinguish between exocrine and endocrine glands, with examples.
Locate the principal endocrine glands in the human.
For each of the glands name one hormone and give its function. For one hormone give a description of its deficiency symptoms, excess symptoms, and corrective measures.
The musculoskeletal system
Functions of the skeleton:
framework of the body
protection of internal organs
assists in movement.
ACTIVITIES
*Use a prepared slide to identify, draw and label the main parts of a T.S. of the spinal cord.
*Write a brief note on paralysis or Parkinson's disease.
SUGGESTED RESOURCES
Prepared slide of T.S. of spinal cord, microscopes or bioviewer.
ACTIVITIES
*Demonstration of the reflex action.
ACTIVITIES
*Use model of the human skeleton to identify the axial and appendicular regions and their main parts.
SUGGESTED RESOURCES
Model of human skeleton.
Contemporary Issues & Technology
Hormone supplements: two examples of their use.
Structural division of the skeleton into two parts the axial and the appendicular .
Component parts of the axial skeleton: skull, vertebrae, ribs, and sternum.
Detail of skull not required.
Position and function of discs in relation to vertebrae.
Vertebrae:
cervical (7), thoracic (12), lumbar (5), sacrum (5), and coccyx (4).
Component parts of the appendicular skeleton:
pectoral and pelvic girdles and their attached limbs.
Pectoral girdle:
clavicle (collar bone)
scapula (shoulder blade).
Attached appendages:
humerus, radius, ulna, carpal, metacarpals, digits (fingers) containing phalanges.
Pelvic girdle: innominate bones (hip bones) attached to the sacrum surrounding a cavity.
Attached appendages: femur, patella, tibia, fibula, tarsals, metatarsals, digits (toes) containing phalanges.
Macroscopic anatomy of a long bone:
not solid but contains a cavity called the medullary cavity bounded by compact bone tapering to spongy bone, a further layer of compact bone and finally a layer of cartilage.
Structure and function of parts as follows
Cartilage: acts as a shock absorber
composed of protein fibres and is flexible.
Compact bone: gives strength and rigidity consists of living cells which are supplied by blood vessels and nerve fibres.
Spongy bone: gives strength and rigidity contains bony bars and plates separated by irregular spaces. These spaces are filled with:
red marrow that produces blood cells
yellow marrow that contains fat-storage tissue.
Note: T.S. of bone is not required.
ACTIVITIES
*Macroscopic examination of a long bone to identify the main parts.
*Show the mineral content in bone and consequently the organic component.
SUGGESTED RESOURCES
Model or longitudinal section of bone; Bone; Acid solution; Tongs
Classification, location and function of joints
Immovable: between skull bones. Slightly movable: between the vertebrae and also between hip bones. Free moving or synovial: describe the structure of one synovial joint. Hinge: e.g. knee or elbow, ball and socket e.g. hip or shoulder.
Role of cartilage and ligaments in joints.
Role of tendons.
General relation of muscles to the skeleton antagonistic muscle pairs as exemplified by one human pair e.g. one muscle bends the joint and brings the limb towards the body, the other muscle straightens the joint and extends the limb.
The defence system in humans
The human body is designed to protect itself from foreign bodies and cells in two orders of defence general and specific.
General defence system consists of: Barrier to entry: the skin and mucous membrane lining of the respiratory, digestive and reproductive tract. The skin, acting as a structural barrier, secretes chemicals from the sebaceous glands that harm or kill bacteria. The respiratory and digestive tracts as well as other organs of the body secrete mucus and/or further chemicals that may remove foreign particles.
Phagocytic white blood cells: some types engulf bacteria and viruses upon contact. Others secrete chemicals that stimulate general defence and cause fever to destroy microbes at high temperatures.
Specific defence system:
- Organs specific to the immune system: the spleen, thymus and lymph nodes.
- Lymph and blood vessels contain cells called lymphocytes and monocytes. Lymphocytes and monocytes are produced in the bone marrow. These cells respond to antigens.
- Antigens are defined as foreign molecules capable of eliciting an antibody response.These may be found in bacterial cell walls, viral coats, foreign cells or produced in cancerous cells.
- Antigen immunity usually lasts for a long time.
- Induced immunity: there are two types of induced immunity active and passive.
Active immunity --
- develops after vaccination or after an infection
- provides long lasting protection.
Passive immunity --
- occurs when individuals are given antibodies to combat the disease, since these are not produced by the body's cells, they are short lived.
ACTIVITIES
*Use model of the skeleton to highlight (a) position and (b) function of each type of joint
SUGGESTED RESOURCES
Model of skeleton
ACTIVITIES
*Investigate and discuss the work of Edward Jenner (1749-1823).
* Investigate antigen/antibody reactions
SUGGESTED RESOURCES
ELISA project
Contemporary Issues & Technology
Vaccination and immunisation.
Contemporary Issues & Technology
Disorders of the musculoskeletal system: one example of a musculoskeletal disorder, from the following: arthritisand osteoporosis; one possible cause, prevention, and treatment.
3.5.4 VIRUSES
DEPTH OF TREATMENT
Viruses:
- identify the problem of definition - living or non-living?
- awareness of the variety of shapes
- basic structure of a virus
- viral reproduction only within living cells therefore can be called obligate parasites.
Contemporary Issues & Technology
Briefly outline the medical and economic importance of virusesto humans, plants, animals. Include reference to two harmfulexamples, one beneficial example e.g. foot and mouth, rabies,polio, influenza, common cold, mosaic diseases of tobacco,tomato, potato, AIDS etc.
HIGHER LEVEL EXTENSION
H.3.5.5 AUXINS
DEPTH OF TREATMENT
Study auxin as an example of a plant growth regulator:
- production site(s)
- function
- different effects.
H.3.5.6 PLANT GROWTH REGULATORS AND ANIMAL HORMONES (EXTENDED STUDY)
DEPTH OF TREATMENT
Explain the mechanism of plant response to any one external stimulus.
Description of the feedback mechanism of any one animal hormonal system.
ACTIVITIES
*Teachers may take this opportunity to discuss a historical or present day human viral infection, such as AIDS, with their students
- its nature
- its transmission
- its effects: individual and numerical
- methods of transmission, control and protection.
SUGGESTED RESOURCES
Refer to Advisory, Research & Developmental Units of the Department of Health, university research units etc.
H.3.5.7 HUMAN IMMUNE SYSTEM (EXTENDED STUDY)
DEPTH OF TREATMENT
Role of lymphocytes:
There are two types of lymphocyte cells: B cells and T cells.
B cells produce antibodies proteins capable of combining with and inactivating antigens by surface recognition. Each B cell produces just one type of antibody.
T cells do not produce antibodies instead they act in one of four processes:
- as helper T cells which recognise antigens, enlarge, and secrete chemicals, such as interferon, which stimulate the production of B cells
- as killer T cells which attack cells containing a foreign antigen, secrete a chemical called perforin that perforates the membranes of cells
- as suppressor T cells which stop immune responses
- as memory T cells which can memorise the immunity, even for life.
H.3.5.8 GROWTH AND DEVELOPMENT IN BONES
DEPTH OF TREATMENT
Bone-forming cells are called osteoblasts which replace cartilage with bone during the growth stage in a human. The bone eventually stops increasing in size and limits the individual adult's height.
In adults, bone is continually being broken down and replaced. As osteoclasts break down bone, osteoblasts build it up. The broken down bone is absorbed by osteoclasts. Osteoclasts remove worn cells and deposit calcium into the blood.
The continued renewal of bone is dependent upon physical activity, hormone levels, and diet.
Role of calcium in bone.
PREAMBLE TO SUB-UNIT 3.6: REPRODUCTION AND GROWTH
In Unit One reproduction was classified as a "characteristic of life".
In Unit Two cellular reproduction was examined in depth.
In this sub-unit we examine reproduction and growth in organisms.
- Sexual reproduction involving the production and transfer of gametes, fertilisation, and development of the embryo as exemplified by the flowering plant and the human.
- Outline growth and development of the embryo as exemplified by the flowering plant and the human.
- Influence of humans on the continuity of organisms of:
(a) their own species
(b) plants.
MANDATORY ACTIVITIES
LABORATORY INVESTIGATION
Students should:
- Investigate the effect of water, oxygen, and temperature on germination.
- Use starch or skimmed milk agar plates to show digestive activity during germination.
3.6 REPRODUCTION & GROWTH / SUGGESTED CLASS PERIODS: 30 OL, 38 HL
3.6.1 REPRODUCTION IN THE FLOWERING PLANT
DEPTH OF TREATMENT
It is advisable to start with an activity that allows students to discover the variety of flowers, structures, colours etc.
Flower structure
Describe the structure and function of the flower parts: sepal, petal, stamen, filament, anther, stigma, style, ovary, carpel, receptacle.
Note: The terms calyx, corolla, androecium, gynoecium are not required.
Pollen grain produces male gametes (statement only).
Embryo sac produces an egg cell and polar nuclei (statement only).
Definition and methods of "pollination": self-pollination and crosspollination, to include wind and animal pollination.
Contemporary Issues & Technology
*Hay fever and pollen:
brief reference to relationship between pollenand hay fever.
ACTIVITIES
* Examine a variety of flowers, ask the students to draw what they see, use a key to name the parts and discover their functions.
* Discuss the evolutionary development and diversity from wind pollination to animal pollination, relate to place (habitat), position and function.
*Examine microscopically a T.S. of an anther to highlight only the position of the pollen sacs and contents.
*Examine a L.S. of a carpel, identify and label its parts.
*Examine: the structure of grass to show adaptation for wind pollination the structure of a flower adapted for animal pollination e.g. primrose, snapdragon etc.
*Play a video on coevolution between plants and their animal pollinators.
SUGGESTED RESOURCES
Variety of flowers; Key to flower parts and functions; Microscopes, Slides, Dissection kits, Anthers. Hand lens Carpels; Grass flowers; Primrose; Snapdragon etc.; Video
"Fertilisation" definition.
When the pollen grain lands on the stigma it germinates forming a pollen tube which grows down through the style to the opening of the embryo sac.
The generative nucleus divides by mitosis in the tube to form two male gametes.
One of these gametes fertilises the female gamete or egg to form a diploid zygote.
After such fertilisation the zygote develops into an embryo.
A second fertilisation with polar nuclei results in the formation of the endosperm.
Seed structure and function of the following parts: testa, plumule, radicle, embryo, and cotyledon attachments by reference to epicotyl and hypocotyl.
As the ovule develops, a seed is formed which consists of an embryo and a food supply. The food supply is contained either in an endosperm or in seed leaves (the cotyledons).
Classification of seeds as monocotyledons containing one seed leaf and dicotyledons containing two seed leaves.
Further distinguishing features In monocots, the cotyledon rarely stores food; rather it absorbs food molecules from the endosperm and passes them on to the embryo.
In dicots, the cotyledons usually store the food that the embryo uses. This is typical of non-endospermic seeds e.g. broad bean seeds.
Fruit formation
Developing seeds produce growth regulators to stimulate growth of the fruit tissues.
Seeds are protected by a seed coat and may be contained within a fruit.
A fruit is a mature ovary or sometimes a modified floral part (e.g. the receptacle) that may contain seeds.
Note: classification of fruits not required.
Fruit and seed dispersal
Seeds are dispersed to ensure a better chance of survival.
Dispersal avoids overcrowding and minimises competition.
ACTIVITIES
*Examine, draw and label the parts of one example of a dicotyledonous non-endospermic seed.
SUGGESTED RESOURCES
Sunflower seeds; Broad bean seeds; Dissecting kits
Contemporary Issues & Technology
Seedless fruit production caused by genetic variety of plants and growth regulators.
Highlight the role of genetics and growth regulators in seedless fruit production, bigger and larger fruit andvegetable production.
Use of ethene to ripen bananas, melons, tomatoes, and to degreen oranges, lemons, grapefruit.
ACTIVITIES
*Examine a variety of fruits and seeds to observe dispersal mechanisms of wind, water, animal internal, animal - external to examine how their structures are related to survival in the habitat.
SUGGESTED RESOURCES
Variety of fruits and seeds
Highlight the wide variety of seed dispersal techniques and examine examples of wind, water, animal and self-dispersal.
"Dormancy" definition.
Outline the advantages of dormancy.
"Germination" definition.
Factors necessary for germination include water, oxygen, and a suitable temperature.
Describe the effect of each of the factors listed on the process of germination.
Outline the role of digestion and respiration. Stages of seedling growth.
Asexual reproduction in plants. A very basic knowledge of vegetative propagation.
One example each from stem, root, leaf, and bud.
Compare reproduction by seed with reproduction by vegetative propagation.
Contemporary Issues & Technology
Artificial propagation in flowering plants.
Exemplify any four methods used by horticulturalists to artificially propagate plants e.g. cuttings,layering, grafting, tissue culturing (micro-propagation).
Contemporary Issues & Technology
Mention of dormancy in agricultural and horticultural practices.
ACTIVITIES
Investigate the effect of water, oxygen, and temperature on germination.
Use starch or skimmed milk agar plates to show digestive activity during germination.
*Examine the stages of: epigeal seedling growth e.g. sunflower; hypogeal seedling growth e.g. broad bean.
Include labelled diagrams of each stage examined.
*Demonstrate the techniques of artificial progagation in flowering plants (details not required by students).
SUGGESTED RESOURCES
Test tubes/petri dishes; Cotton wool or absorbing paper; Oxygen controls; Temperature controls; Starch/ skimmed milk agar plates; Germinating barley seeds; Iodine solution**; Potting compost; Containers; Broad bean seeds; Sunflower seeds; Samples of stems, roots, leaves and buds suitable for vegetative propagation.
3.6.2 SEXUAL REPRODUCTION IN THE HUMAN
DEPTH OF TREATMENT
The human reproductive system is organised as follows: male/female paired structures in which male gametes, sperm/female gametes, eggs (ova), are produced
- a series of transport tubes
- glandular structures for the secretion of various hormones that control the entire process.
The human male reproductive system
Identify and draw the main parts of the human male reproductive system and associated glands.
Describe the function of each labelled part.
Particular emphasis should be placed on the role of meiosis in the production of sperm cells in the testis.
(Note: Detailed treatment of spermatogenesis is not required).
Definition of "secondary sexual characteristics".
The role of the male reproductive hormone, testosterone, in the development and maintenance of the adult male.
The human female reproductive system
Identify and draw the main parts of the human female reproductive system and associated glands.
Describe the function of each labelled part.
Particular emphasis should be placed on the role of meiosis in the production of egg cells (ova) in the ovary.
(Note: Detailed treatment of oogenesis is not required).
The role of the female reproductive hormones, oestrogen and progesterone, in the development and maintenance of the adult female.
The events of the menstrual cycle including the role of oestrogen and progesterone.
ACTIVITIES
*From diagrams or model of the male reproductive system:
draw and label the main parts
describe their functions.
SUGGESTED RESOURCES
Charts Models
Contemporary Issues & Technology
One cause of male infertility from the following disorders:low sperm count, low sperm mobility, endocrine gland failure.Availability of corrective measures.
Outlined stages of copulation in both male and female to include:
sexual arousal
copulation
orgasm.
Survival time for sperm and ova.
Location of fertilisation.
Implantation, placenta formation and function (detailed embryological terms not required).
Birth and lactation.
Outline how birth occurs.
Role of hormones in the process of birth and lactation.
Contemporary Issues & Technology
One cause of female infertility from the following disorders:blocked fallopian tubes, endocrine gland failure
Availability of corrective measures.
Birth control:natural, mechanical, chemical andsurgical methods of contraception.
In-vitro fertilisation and implantation:outline the biological principles underlying in-vitro fertilisationand the implantation of embryos.
Biological benefits of breastfeeding.
ACTIVITIES
*From diagrams or model of the female reproductive system:
- draw and label the main parts
- describe their functions.
*Use acetates to highlight the hormonal control associated with the menstrual cycle.
*Use acetates, videos or samples to identify and explain methods of contraception.
*Use acetates or models of the female reproductive system to show the development of the embryo to the end of the third month.
SUGGESTED RESOURCES
Chart; Models; Acetates; Overhead projector; Leaflets on "periods" from the Council for the Status of Women and Health Promotion Unit, Department of Health. Acetates; Overhead projector; Video or samples; Leaflets on "Family Planning and Contraception", Health Promotion Unit, Department of Health. Acetates; Overhead projector; Models of the female reproductive system; Leaflets from Health Promotion Unit, Department of Health. "Breast feeding the early days of getting started" Cuidiú (Irish Childbirth Trust), La Leche League.
HIGHER LEVEL EXTENSION
H.3.6.3 SEXUAL REPRODUCTION IN THE FLOWERING PLANT (EXTENDED STUDY)
DEPTH OF TREATMENT
Pollen grain development from microspore mother cells: meiotic division, mitotic division, generative nucleus and tube nucleus production, formation of pollen grain.
Embryo sac development: megaspore mother cell, meiotic division, cell disintegration, mitotic division in the production of eight cells in the embryo sac, one of which is the egg cell.
(Note: Antipodal cells and synergids not required.)
H.3.6.4 HUMAN EMBRYO DEVELOPMENT (EXTENDED STUDY)
DEPTH OF TREATMENT
Sequence of development from fertilised egg, morula, blastocyst, implanted blastocyst.
Existence of amnion.
Mention of placenta formation from embryonic and uterine tissue.
Significance of organisation of the embryo cells into three germ layers: endoderm, mesoderm and ectoderm.
List of basic organ systems that arise from each of the primary germ layers.
By the end of the third month
- the eyes are low and widely spaced
- bone tissue appears, grows and cartilage is replaced by harder tissue
- nerves and muscles become co-ordinated, arms and legs move
- sex organs differentiate, male or female is obvious in the twelfth week
- the foetus sucks its thumb, kicks, begins to grow baby teeth
- breathes amniotic fluid in and out, urinates and defecates into it
- in the remaining months the baby grows.
H.3.6.5 SEXUAL REPRODUCTION IN THE HUMAN (EXTENDED STUDY)
DEPTH OF TREATMENT
Detailed study of the menstrual cycle and hormonal control.
Contemporary Issues & Technology
Menstrual disorders:
Choose one example of a menstrual disorder from the following: endometriosisand fibroids;one possible cause, prevention and treatment.