Part 1
NAME:…………………………………………CLASS:……………………………………………….
SEKOLAH MENENGAH SAINS SERI PUTERI
KUALA LUMPUR
1.1 The Importance of having a Transport system in Multicellular Organisms
1. Unicellular organisms such as Amoeba sp do not need an internal transport system. They obtain oxygen and nutrients from the external environment and eliminate waste substances by diffusion through the plasma membrane. These organisms have either a thin flattened body or a large surface area to further enhance diffusion.
2. Small organism have greater total surface area / volume (TSA/V) ratio that enable substances to diffuse easily into the cell. Hence they do not need any internal transport system.
3. The greater the TSA/V ratio, the higher the rate of diffusion into the organism
4. In multicellular organisms, the TSA/V decreases. Cells are located far away from the external surface of the body. The decreased TSA/V ratio and the diffusion rate over the large distances are the limiting factors to cellular activities .
5. Hence, the multicellular organisms have specialised structure to increase the surface area for the exchange of substances. They need circulatory system to carry out the distribution of nutrients and oxygen throughout the body and the removal of waste products from the body.
Experiment 1: To study the relationship between the size of an object and the effect of TSA/V on the rate of diffusion of a substance.
*Design an experiment.
1.2 The Circulatory System
- Circulatory system in humans and animals
1. The blood circulatory system consists of two types :
a) Open circulatory system
b) Closed circulatory system
Task 1: Define Open circulatory system and Closed circulatory system
2. The circulatory system in a human consists of :
a) The cardiovascular system.
b) The lymphatic system
3. The circulatory system includes three components.
a) Medium or transport (blood or haemolymph in insects )
b) Blood Vessels (artery, vein and capillary which carry blood)
c) Pump ( heart )
4. The heart pumps the blood to the cells through the vessels.
5. In insects : The tubular hearts pump the haemolymph into spaces in the body called haemocoel. Digested food diffuse through the cells in the haemocoel while waste substances diffuse out.
6. Haemolymph is a circulating blood-like fluid in some invertebrates with open circulatory system. It is not confined to vessels only.
7. Haemolymph transports water, inorganic salts/nutrient such as digested food substance and hormone throughout haemocoel.
8. Unlike blood, Haemolymph does not transport respiratory gases
9. The haemolymph consist of vessels and tubular heart shape. The tubular heart will pump the haemolymph into the haemocoel.
10. Nutrients and hormones diffuse from haemolymph into the cells. Waste products diffuse out from the cells into the surrounding haemolymph.
- Composition of human blood
1. Blood is a connective tissue.
2. Blood consists of plasma and cellular components which are the blood cells.
3. Plasma is a pale yellow liquid which makes up 55% of the blood whereas the cellular components make up 45% of the blood.
4. 90% of plasma consists of water while the remaining 10% consists of dissolved solutes.
5. Dissolved solutes in the plasma are proteins, nutrients, mineral salts, hormones, antibodies, waste products and gases.
6. Proteins in plasma are albumen, fibrinogen and immunoglobulins. Fibrinogen is involved in blood clotting whereas immunoglobulins are antibodies which are involved in the body defence mechanism.
7. Mineral salts such as potassium, sodium, calcium, magnesium and chloride ions are important to maintain the pH and the osmotic pressure of the blood.
8. Hormones are proteins in the form of liquids excreted by endocrine glands and release into the bloodstream. Each hormone is transported by the blood to carry out various functions in the body.
9. Water helps to dissolve the substances that have to be transported.
10. The cellular components consist of three types of blood cells namely : erythrocytes, leucocytes and platelets.
Task 2:
Draw a chart to show the composition of the human blood
- Erythrocyte, Leucocytes and Platelets
1. Erythrocytes are red blood cells that contain haemoglobin. Haemoglobin is a protein which contains four atoms of iron that bind oxygen or carbon dioxide in the blood circulatory system.
2. Leucocytes or the white blood cell consists of granulocytes and agranulocytes.
3. Granulocytes have granules in their cytoplasm’s and lobed nuclei by detoxifying chemical.
4. Agranulocytes do not have granules in their cytoplasms and have nuclei which are not lobed.
a) Granulocytes
i. Basophils secrete heparin to prevent blood clotting.
ii. Eosinophils help to control allergy by detoxifying chemicals.
iii. Neutrophils destroy bacteria through phagocytosis.
b) Agranulocytes
i. Monocytes destroy bacteria through phagocytosis.
ii. Lymphocytes produce antibodies which destroy pathogens or antitoxins which neutralise toxins produces by bacteria.
6. Leukaemia or blood cancer is a disease where excessive leucocytes are produced.
7. Anaemia is a disease in which oxygen and nutrients cannot be transported due to lack of erythrocytes.
8. Platelets or thrombocytes are incomplete cells which are found as fragments in the bone marrow.
9.
Table shows similarities and differences between erythrocytes , leucocytes , platelets.
1. The nucleusless cytoplasm of an erythrocyte provides more space to bind with haemoglobin.
2. The biconcave disc-shaped of an erythrocyte increases the surface area for gaseous exchange and aids in squeezing through blood capillaries.
3. The irregular shape of a leucocyte enables it to squeeze through blood capillaries and destroy pathogens.
Function of blood in transport … (Essay paper 2)
Blood transports…..
a) Oxygen from the lungs to other parts of the body. Haemoglobin combines with oxygen to form oxyhaemoglobin to send oxygen to cells for cellular respiration.
b) Carbon dioxide from the cells to the lungs. About 23% of the carbon dioxide releases from cellular respiration combines with haemoglobin to form carbaminohaemoglobin. Another 7% of the carbon dioxide dissolves in the blood plasma. In the way, carbon dioxide is transported to the lungs.
c) Soluble digested food materials from the villi of the small intestine to body tissues.
Vitamins, minerals, simple sugars such as glucose, amino acids, water soluble vitamin are transported via the hepatic portal vein from small intestine to the liver then to the heart. Fatty acids, glycerol and fat soluble vitamins (ADEK) transported by the lymph into the blood circulatory system via the left subclavian vein.
d) Excretory waste products such as urea. Urea formed from the deamination of excess amino acids in the liver is transported to the kidneys for excretion.
e) Heat to the skin to be excreted and to regulate body temperature by distributing heat.
f) Hormones produced by the endocrine glands to the target organs to carry out their specific functions.
g) Water to tissues to provide a medium for biochemical reactions.
Human blood vessels
1. There are three types of human blood vessels: arteries, capillaries and veins.
2. An artery is blood vessel which carries oxygenated blood away from the heart. It branches out into arterioles which then branch out into capillaries.
3. Capillaries join with one another to form venules which then join together to form veins.
4. Veins transport deoxygenated blood back to the heart.
Lymphatic Filariasis a.k.a. elephantiasis : Pls goggle!
