The Concept of Transportation of Materials in Living Things
The Concept of Transportation of Materials in Living Things
Explain the concept of transportation of materials in living things
Unicellular organisms (for example amoeba), nutrients (for example oxygen and food) and waste products (for example carbon dioxide) can simply diffuse into or out of the cells from the surroundings. But in multi cellular organisms (for example humans and trees), many cells are very far away from the body surface, hence a transport system is required for the exchange of materials.
Organisms require transport systems so as to carry out various life processes. These life processes include nutrition, respiration, excretion, growth and development, movement,reproduction and coordination. For these life processes to take place, transport of materials is inevitable. Materials are transported either from environment into the organisms or from one part of an organism to another, and can also be transported from an organism into the environment.
For example, during nutrition organisms take in food substances that they need to produce energy, grow and carry out other life processes. These food substances must be taken in from the environment. The same case applies to reproduction which requires the movement of gametes(sex cells) from the sex organs to the area where fertilization occurs. Therefore, transport is very important for the survival and existence of living things.
The Importance of Materials in Living Things
Outline the importance of materials in living things
Transport of materials is very important for the survival and development of living organisms. If transportation never existed, then no life on earth could be possible. The following is an outline of the importance of transport of materials in living things:
Diffusion, Osmosis and Mass- flow
The Meaning of Osmosis, Diffusion and Mass- Flow
Explain the meaning of osmosis, diffusion and mass- flow
Life processes in organisms take place at the cell level. Therefore, it is necessary for substances to move in and out of the cells. There are two ways through which substances can move across the membrane. Materials in living organisms move by diffusion, osmosis and mass flow.
This is the movement of materials from a region of higher concentration to a region of lower concentration until equilibrium of two sides is maintained. Diffusion can also be defined as the movement of ions or molecules from the region of higher concentration to the region of lower concentration, without involving any permeable membrane. A difference in concentration of a substance between two regions is known as concentration gradient.
Diagram showing diffusion
Materials are transported in the body system of living things from the area where they are abundant to areas where they are less abundant, and this process or mechanism of transportation in these animals is termed as diffusion. Diffusion occurs in exchange of gases like oxygen or carbon dioxide during respiration in animals and plants. Also, diffusion takes place during distribution of nutrients and digested foods in living organisms.
Experiments to Demonstrate the Process of Diffusion, Osmosis and Mass Flow
Carryout experiments to demonstrate the process of diffusion, osmosis and mass flow
The Differences between Diffusion, Osmosis and Mass Flow
Outline the differences between diffusion, osmosis and mass flow
The Roles of Diffusion, Osmosis and Mass Flow in Movement of Materials in Living Organisms
Explain the roles of diffusion, osmosis and mass flow in movement of materials in living organisms
Materials are transported in the body system of living things from the area where they areabundant to areas where they are less abundant, and this process or mechanism of transportationin these animals is termed as diffusion. Diffusion occurs in exchange of gases like oxygen orcarbon dioxide during respiration in animals and plants. Also, diffusion takes place duringdistribution of nutrients and digested foods in living organisms.
Through the process of osmosis, nutrients get transported to cells and waste materials getmoved out of them.
The pressure within and outside each cell is maintained by osmosis as this process ensures abalance of fluid volume on both sides of the cell wall. If fluid volume within a cell is morethan the fluid volume outside it, such pressure could lead the cell to become turgid andexplode. On the contrary, if fluid volume outside the cell is more than the fluid volumewithin, such pressure could lead the cell to cave in. Both cases would be detrimental tonormal and healthy cellular function.
It is via osmosis only that roots of plants are able to absorb moisture from the soil andtransport it upwards, towards the leaves to carry out photosynthesis. Plants wouldn’t existwithout osmosis; and without plants, no other life could exist as they are a vital link of theentire food chain of the planet.
Without osmosis, it would be impossible for our bodies to separate and expel toxic wastesand keep the bloodstream free from impurities. The process of blood purification is carriedout by the kidneys which isolate the impurities in the form of urine.
Therefore, the role of osmosis is twofold: it helps maintain a stable internal environment in aliving organism by keeping the pressure of intercellular and intracellular fluids balanced. It alsoallows the absorption of nutrients and expulsion of waste from various bodily organs on thecellular level. These are two of the most essential functions that a living organism cannot dowithout.
The External and Internal Structures of the Mammalian Heart
Describe the external and internal structures of the mammalian heart
The Functions of the External and Internal Parts of the Mammalian Heart
Explain the functions of the external and internal parts of the mammalian heart
The Adaptations of the Parts of the Mammalian Heart to their Functions
Explain the adaptations of the parts of the mammalian heart to their functions
The heart is adapted to carry out its functions by having the following features:
The cardiac muscle is adapted to be highly resistant to fatigue.
The heart has a large number of mitochondria enabling continuous supply of energy to theheart and numerous myoglobins (oxygen storing pigment).
The presence of the cardiac muscles enables the heart to beat rhythmically.
The pericardium which surrounds and protects the heart from physical damage.
Pericardial fluid which prevents friction when the heart beats.
The outer layer of the pericardium attaches to the breastbone and other structures in the chestcavity and thus helps to hold the heart in place.
Bicuspid and tricuspid valves between atria and ventricles which prevent the backflow ofblood.
Septum which prevents the mixing of deoxygenated blood in the right and oxygenated bloodin the left chambers of the heart.
Its own blood supply for supplying nutrients and removing waste.
The left ventricle has thick muscular wall to pump blood at a higher pressure to the distantbody tissues,
The heart is supplied with the nerves which control the rate of heartbeat depending on thebody requirements.
The Structure of Arteries, Veins and Capillaries
Describe the structure of arteries, veins and capillaries
Simple Experiments to Determine Pulse Rates in Human Being
Carry out simple experiments to determine pulse rates in human being
Carry out simple experiments to determine pulse rates in human being
The Major Components of the Blood
List the major components of the blood
Blood is the red fluid that circulates in our blood vessels. The average human body containsabout 4 to 5 litres of blood. Blood is classified as a connective tissue and consists of two maincomponents:
Plasma which is a clear extracellular fluid.
The solid component, which are made up of the blood cells and platelets
The solid component is made up of blood cells except for the platelets, which are tiny fragmentsof bone marrow cells.
The solid component consists of blood cells (corpuscles) which include:
Erythrocytes, also known as red blood cells (RBCs)
Leukocytes, also known as white blood cells (WBCs)
Platelets, also known as thrombocytes
Red blood cells, most white blood cells, and platelets are produced in the bone marrow, the softfatty tissue inside bone cavities. The white blood cells (lymphocytes) are also produced in thelymph nodes and spleen, and in the thymus gland.
Within the bone marrow, all blood cells originate from a single type of unspecialized cell calleda stem cell. When a stem cell divides, it first becomes an immature red blood cell, white bloodcell, or platelet-producing cell. The immature cell then divides, matures further, and ultimatelybecomes a mature red blood cell, white blood cell, or platelet.
By volume, the plasma constitutes about 55% of whole blood, and red blood cells, platelets and white blood cells about 45%.
The Function of Major Blood Components
Explain the function of major blood components
The Effects of HIV on White Blood Cells
Explain the effects of HIV on white blood cells
The HIVs in the blood of a HIV-positive person attack the white blood cells (lymphocytes). Theviruses reproduce and increase in number within the lymphocytes. Then the lymphocytes burstand release more viruses in the bloodstream. The released viruses attack more, new white cells.The attack continues in that cycle until many white cells are destroyed. Because there are only afew white cells left to fight against pathogens, the body immunity gets low. Once the immunityis lowered, the body is often attacked by diseases and a person suffers from AIDS.
The Concepts of Blood Group and Blood Transfusion
Explain the concepts of blood group and blood transfusion
Human blood can be grouped into four blood groups namely groups A, B, AB and O. They werediscovered in 1900 and 1901 at the University of Vienna by Karl Landsteiner in the process oftrying to learn why blood transfusions sometimes cause death and at other times save a patient.This classification is based on the type of antigens in the red blood cells and antibodies in theplasma.
Red blood cells have proteins (antigens) on their surface: A, B or A and B. Plasma hasantibodies which can cause agglutination: anti-A and anti-B.
Serum is blood plasma without fibrinogen. It can be stored without clotting, and is used intransfusions.
||A and B
||Anti-A and anti-B serums
||Anti-A and anti-B
Consider the table above. People with type A blood will have the A antigen on the surface oftheir red cells (as shown in the table). As a result, anti-A antibodies will not be produced bythem because they would cause the destruction of their own blood. However, if B type blood isinjected into their systems, anti-B antibodies in their plasma will recognize it as alien and burstor agglutinate the introduced red cells in order to cleanse the blood of alien protein.
Individuals with type O blood do not produce any antigens. Therefore, their blood normally willnot be rejected when it is given to others with different blood types. As a result, type O peopleare universal donors for transfusions, but they can receive only type O blood themselves. Thosewho have type AB blood do not make any antibodies. Their blood does not discriminate againstany other blood type. Consequently, they are universal receivers for transfusions, but their bloodwill be agglutinated when given to people with every other type because they produce both kindsof antigens.
The Relationship between Blood Groups and Blood Transfusion
Outline the relationship between blood groups and blood transfusion
The Advantages and Disadvantages for Blood Transfusion
Explain the advantages and disadvantages for blood transfusion
Precautions to be Taken During Blood Transfusion
Outline precautions to be taken during blood transfusion
Blood Circulation in Humans
Describe blood circulation in humans
Blood circulation is the flow of blood from the heart to all body parts and back to the heart.Blood circulation or circulatory system, also called cardiovascular system, is one of three mainsystems in human body which consist of organs and tissues.
The cardiovascular systems of humans are closed, so the blood never leaves the network of bloodvessels. But oxygen and nutrients diffuse across blood vessel layers and enter interstitial fluid,which carries it to the target cells and carbon dioxide and wastes in the opposite direction.
The human blood circulation consists of two circulations namely the pulmonary circulation andsystemic circulation.
The Importance of Blood Circulation in Humans
Explain the importance of blood circulation in humans
Disorders and Diseases of the Human Blood Circulatory System
Mention disorders and diseases of the human blood circulatory system
The Causes, Symptoms and Effects and Control/Measures of the Disorders and Diseases of the Human Blood Circulatory System
Outline the causes, symptoms and effects and control/measures of the disorders and diseases of the human blood circulatory system
Practical Exercises to Measure Human Pulse Rate and Blood Pressure
Carry out practical exercises to measure human pulse rate and blood pressure
Carry out practical exercises to measure human pulse rate and blood pressure.
The Concept of Lymphatics
Explain the concept of lymphatics
The lymphatic system is a network of tissues and organs that primarily consists of lymph vessels,lymph nodes and lymph. The tonsils, adenoids, spleen and thymus are all part of the lymphaticsystem.
There are 600 to 700 lymph nodes in the human body that filter the lymph before it returns to thecirculatory system.
The spleen, which is the largest lymphatic organ, is located on the left side of the body just abovethe kidney.
The thymus, which stores immature lymphocytes and prepares them to become active T cells, islocated in the chest just above the heart.
Tonsils are large clusters of lymphatic cells found in the pharynx.
The Components of the Human Lymphatic System
Describe the components of the human lymphatic system
The Human Lymphatic System
The Common Disorders and Diseases of the Lymphatic System
Mention the common disorders and diseases of the lymphatic system
There are several diseases and disorders that affect the lymphatic system. The two commondisorders of the lymphatic system are lymphoedema and lymphatic filariasis (elephantiasis).
Causes, Symptoms, Effects and Prevention of Disorders and Diseases of the Human Lymphatic System
Explain causes, symptoms, effects and prevention of disorders and diseases of the human lymphatic system
The Concept of Vascular System
Explain the concept of vascular system
Components of Vascular System
Describe components of vascular system
The vascular (transport) system in plants is made of vascular bundles. The vascular bundles aremade of xylem and phloem which are separated by a wall called vascular cambium, often simplyshortened as cambium (see diagrams discussed in the previous section).
The Function of Vascular System in Plants
Explain the function of vascular system in plants
The vascular system is mainly responsible for transportation of materials within a plant body.The xylem and phloem tissues are specialized to perform different functions in a plant body.
The Functions of Root Hairs in Absorption and Movement of Water and Mineral Salts in Plants
Explain the functions of root hairs in absorption and movement of water and mineral salts in plants
The Movement of Water and Dissolved Mineral Salts in Plants
Outline the movement of water and dissolved mineral salts in plants
Experiments to Demonstrate Transpiration pull, Root Pressure and Capillarity
Conduct experiments to demonstrate transpiration pull, root pressure and capillarity
The Concept of Transpiration
Explain the concept of transpiration
Transpiration is the evaporation of water from plants. It occurs chiefly through the leaves whiletheir stomata are open for the passage of carbon dioxide and oxygen during photosynthesis.
Transpiration also occurs through the cuticle and lenticels. Lenticels are pores in the stems ofwoody plants that allow gaseous exchange between the atmosphere and the internal tissues.
The Significance of Transpiration in Plants
Outline the significance of transpiration in plants
Transpiration is of immense importance in plant life as it is of great benefit to the plant. Thefollowing are the reasons why transpiration is important in plants.
Factors Affecting the Rate of Transpiration in Plants
Outline factors affecting the rate of transpiration in plants
The rate of transpiration can be affected by both plant features and environmental factors.