Life Processes (c) Transportation

Plasma is a straw colored liquid which comprises of almost 55% of the blood. It is a very important as it allows the medium to blood corpuscles to move freely in the body. Plasma constitutes water which is about 90-92% and nearly 6-8% proteins like fibrinogen, globulins and albumins and remaining some ions like Na⁺, Cl^- etc.

Blood is a very important connective tissue and has two main components which are:

i) Plasma: It is the fluid part which is about 55% of the total blood. It is a straw colored liquid, viscous in nature. Plasma comprises of about 90-92% of water and 6-8% proteins.

ii) Formed elements: Blood cells/ corpuscles all the formed elements constitutes about 45% of the total blood. It include the red blood cells (erythrocytes), white blood cells (leucocytes) and the platelets (thrombocytes). Out of these platelets are not the proper cells but the cell fragments which play a major role in the process of blood clotting.

Platelets are the cells which help in coagulation clotting of blood. Platelets are also known as thrombocytes and instead of being proper cells they are the cell fragments which are produced by megakaryocytes. They are 1.5 lakh to 3.5 lakh per cubic millimeter of blood.

Blood platelets or thrombocytes are the cell fragments produced by megakaryocytes. During any injury, platelets release a substance called thromboplastin. This thromboplastin helps in the formation of a complex enzyme thrombokinase which converts prothrombin into active thrombin. This thrombin converts soluble fibrinogen into insoluble fibrin. This fibrin forms a network at the site of injury which traps the blood & form clot.

Human heart has four chambers that is two auricles and two ventricles. Auricles are the small chambers whereas ventricles are the bigger ones. Our heart has four chambers so as to prevent the mixing of oxygenated and deoxygenated blood. This increases the working efficiency of organism.

Human heart has various types of valves present in between the different chambers. Bicuspid valve is present between the left atrium and ventricle whereas tricuspid valve is present in between the right auricle and the right ventricle.

Semilunar valve is present between right ventricle & pulmonary artery and left ventricle & aorta. The important role of these valves is to prevent the backflow of blood from the ventricles to the auricles.

Fishes have two chambered heart. The heart includes one auricle and one ventricle. But two chambereed heart is less efficient because in two chambered heart mixing of oxygenated and deoxygenated blood occurs. That is why two chambered & three chambered heart evolved into four chambered heart in humans as it prevents mixing of oxygenated and deoxygenated blood.

Sphygmomanometer is a device to monitor blood pressure in humans. It has a cuff which is tied on the arm of the patient and then the blood pressure is monitored by observing the rise and fall in the mercury level.

Lymph is a colorless liquid which is released out of the tissues. It is so because lymph contains only WBCs and not RBCs. Since the WBCs are colorless, lymph is also colorless. It has the same mineral composition as that of the plasma.

We need a proper transportation system in almost all the organisms whether be it plant or animals. Roots take up water which is required by the whole plant body. In the same way food is produced by the leaves which is to be distributed to the whole plant, therefore, a proper transportation system is needed to fulfill all the requirements of the plant.

Xylem and phloem are the conducting structures which are present in plants. Xylem is responsible for transportation of water and minerals whereas phloem is responsible for translocation of food.

The process of movement of water in the plants through xylem and its evaporation through leaves or stem is known as transpiration. It is done through stomata during the daytime. It is important as it creates a pull which is known as transpirational pull in the xylem which is responsible for uptake of water. It also produces a cooling effect on plants and maintains the temperature of plant. Moreover is also prevents water logging in the plant.

Movement of carbohydrates (sugars) produced by the leaves of the plant in the whole plant body through phloem is known as translocation. It is an important process as other parts of the plant which do not synthesize food also gets access to food produced by leaves.

Translocation is the process of movement of carbohydrates (which act as food ) produced by the leaves which is to be distributed to different parts of the plant. The process of translocation takes place in the phloem cells. Thus the cell involved would be companion cells, sieve elements & parenchymatous tissue.

The valves present between the auricles and ventricles and between the ventricles and pulmonary artery and aorta prevent backflow of blood. Bicuspid or mitral valve is present in between left auricle and left ventricle. Tricuspid valve is present in between right auricle and right ventricle. Semilunar valves are present in between right ventricles & left ventricle and pulmonary artery & aorta respectively.

The blood leaving the tissues becomes very rich in the carbon dioxide content. When the oxygenated blood reaches the tissues, it gives oxygen to the tissues and take up the carbon dioxide emitted from them and takes it back to the heart.

The contraction of the right atrium results in to flow of blood from right atrium to the right ventricle. The flow of blood is guarded by the tricuspid valve which prevent the backflow of blood into the right atrium.

When the muscles of heart contract it leads to systole and the relaxation of heart muscles after systole is known as diastole. The systolic and diastolic pressure of a normal man is 120/80 mmHg. In this, 120 mmHg represents the systolic pressure whereas 80 mmHg represents the diastolic pressure.

Four major roles played by RBC ae-

(i) it contains a respiratory pigment called as Haemoglobin.

(ii) transportation of oxygen in the body

(iii) removal of carbon-dioxide from tissues.

(iv) contains an enzyme carbonic anhydrase which is very important for CO₂ transport.

There are major differences in the blood circulation of fishes & birds.

Heart in fishes is 2-chambered while heart in birds is 3-chambered. In fishes the blood enters in the heart only during one whole circulation a single time while in birds it enters twice during one complete circulation. In fishes, both oxygenated & deoxygenated blood gets mixed and then circulated to the whole body, while in birds both oxygenated & deoxygenated remains separated and thus more efficient.

i) Xylem and phloem

Xylem and phloem are the conducting tubes present in the plant which are responsible for the transportation of different materials required by the plant body.

ii) Haemoglobin and chlorophyll

Both of them are the colored pigments just present in different organisms. Haemoglobin is present in animals whereas chlorophyll is present in plants.

Translocation: The process of movement of carbohydrates (which act as food) produced by the leaves which is to be distributed to different parts of the plant is known as translocation. The process of translocation takes place in the phloem cells.

Transpiration : The process of movement of water in the plants through xylem and its evaporation through leaves or stem is known as transpiration. It is done through stomata during the daytime. It is important as it creates a pull which is known as transpirational pull in the xylem.

Firstly, blood is mesodermal origin just the way all other connective tissues are. Secondly, blood connects different parts of the body, transporting minerals, nutrients, hormones and collecting waste from different parts. Hence, blood is known as a fluid connective tissue.

Platelets help in clotting of blood. There are 13 different factors which affect the clotting mechanism. A clot is a reddish brown scum made up of fibre like structures known as fibrins. The important steps in clotting mechanism can be explained below:-

step-1:- release of thromboplastin from injured tissues & platelets

step-2:- This thromboplastin helps in the formation of a complex enzyme thrombokinase.

step-3:- this thrombokinase converts prothrombin into active thrombin

step-4:-. This thrombin converts soluble fibrinogen into insoluble fibrin.

step-5:- This fibrin forms a network at the site of injury which traps the blood & form clot.

The basophils (a type of WBC) and mast cells present in our body (a part of formed elements ) secrete an anti-coagulant known as Heparin. This anti-coagulant do not let the blood clot inside the blood vessels.

In the single circulation the deoxygenated blood from the whole body of the animal spammed into the heart. From the heart it goes to the gills and the oxygenated blood is pumped back into the body. This kind of circulation takes place in fishes. Whereas in double circulation the deoxygenated blood is collected from the body, goes to the lungs for the process of oxygenation and then this oxygenated blood comes back to the heart. The heart pumps back this oxygenated blood into the body tissues. In this type of circulation, as the blood passes through the heart two times, it is known as double circulation. It takes place in birds & mammals like human beings.

Another type of circulatory fluid in the human body is the lymph. Lymph is a colorless liquid which is formed out of blood plasma.

The deoxygenated blood is collected from the body tissues through the veins which further combine to form vena cava. This vena cava pours deoxygenated blood collected from the body tissues into the right auricle of heart. From right auricle it goes to right ventricle and from here the blood is pumped into the pulmonary artery which takes the deoxygenated blood from heart to the lungs. In the alveoli of lungs the blood is oxygenated. This oxygenated blood is pumped into the pulmonary veins which pours the blood into the left auricle. From here the oxygenated blood is poured into the left ventricle. The left ventricle pushes the blood into the aorta which pumps the oxygenated blood into the body tissues and supply oxygen through the tissues for various body functions.

i. The soil is the richest source of raw materials for the plant like nitrogen, phosphorous, water and other minerals. Water is essential for all physiological activities of the plant. The absorption of all these substances occurs through a part of the plant called roots.

ii. The plant transport system moves raw materials from roots and energy from leaves. This is done by two independent conducting tubes called xylem which transports water and minerals from the soil and phloem transports the food from leaves to other parts of plants. vessels tracheids of xylem tissue, stem, leaves, and roots form a continuous water conducting channel reaching to all parts of the plant.

iii. The difference of concentration of ions in roots and soil, help water to enter roots from the soil to eliminate this difference (caused by root cells take up ions from soil). This maintains the steady movement of water upwards via roots.

iv. But this pressure is not enough to supply water to heights.

v. Water lost through leaves (or any aerial part of the plant) called transpiration causes a suction which pulls water from xylem cells of roots. Thus, transpiration helps in the absorption and upward movement of water and minerals from soil via roots and reach the top. Also, it helps to regulate the temperature of the plant.

The food for plants is prepared by the green leaves by the process of photosynthesis. In this process the plant uses carbon dioxide and produce sugars in the presence of sunlight. Every part of plant body like the roots and stem also require food for its functioning so the food prepared by the leaves must be transported to different parts of the plant. The process of transportation of carbohydrates (sugar) produced by the leaves to other parts of the plant is known as translocation. It is done through Phloem tissues. The movement of carbohydrates in phloem is bidirectional.

Water is absorbed by the root of the plant but has to be transported to different parts of the plant like leaves and stem. It is done through xylem tissues. The flow of water and minerals in xylem is unidirectional that is from roots to leaves. The process of movement of water in the plants through xylem and its evaporation through leaves or stem is known as transpiration. It is done through stomata during the daytime. It is important as it creates a pull which is known as transpirational pull because of which the water moves from the roots to the leaves.

(i) Transpiration is the process of movement of water in the xylem tissues and its evaporation through the aerial structures of the plant like leaves and stem. It causes a transpirational pull which help in the movement of water from the roots to the leaves.

(ii)(a) when humidity is decreased, transpiration is increased

(b) By increasing the temperature of the surroundings, we tend to increase the rate of evaporation of water droplets through the leaves by the process of transpiration. On increasing temperature, rate of transpiration also increases.

(iii) Amit is very interested in science subject. He believes in applying practical knowledges into real life experience.

(i) The color of the blood is red because of the presence of haemoglobin. Haemoglobin is a pigment which is found in the red blood cells. Even the color of RBCs is because of the presence of haemoglobin in them. It is useful as four molecules of oxygen combine to one molecule of Haemoglobin and thus help in oxygen transport.

(ii) Blood do not clot in our blood vessels because of the presence of a natural anti coagulant Heparin which is released by the basophils and the mast cells in our body. Hence, unclotted blood comes out from the site of injury even when platelets are present.

(iii) There are three types of blood cells found in human beings. They are: red blood cells, white blood cells and the platelets. Different types of cells have different function. The type of blood cells which protect us from various kinds of infections in our body are the White Blood Cells or the Leucocytes. They are phagocytic in nature and hence, eat up the infection causing agent.

(iv) Sumay must be very serious before doing anything. But at least he realized it before doing anything dangerous.

The part of the diagram labeled as b will have the highest blood pressure in the whole circulatory system. The part labeled as b represents aorta. It is the largest artery which supplies the oxygenated blood from the left ventricle of heart to the body tissues. It has the highest pressure as the left ventricle has to pump the blood to all the body parts.

1- pulmonary artery

2- vena cava

3- aorta

4- pulmonary vein

The deoxygenated blood collected from different body parts is poured into the right auricle. From right auricle it moves to the right ventricle and through the pulmonary artery this is deoxygenated blood is pumped into the lungs where it is oxygenated. Then this oxygenated blood is transported to the left Atrium and then moves to the left ventricle from where it is pumped into the whole body.

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The process of movement of water in the plants through xylem and its evaporation through leaves or stem is known as transpiration. Transpiration supplies water for photosynthesis, cools the leaves surface through evaporation, and the transpirational pull helps in transportation of minerals from the roots to the leaves. But it never helps in the translocation of sugars. Translocation is the process of movement of food from the leaves to the different parts of the plant through phloem.

Aorta is the only blood vessel which transports the oxygenated blood from the heart to different parts of the body. As the blood is oxygenated and this blood vessel the oxygen concentration is high, carbon dioxide concentration is low and the blood pressure is very high so as to supply the oxygenated blood to different parts of the body

Xylem helps in transportation of water & mineral in the plant body and it also provides support.

Lower surface of leaf has more stomata than upper surface. That is why maximum transpiration occurs.

The deoxygenated blood is collected from different parts of the body and transported into the right atrium from which it moves to the right ventricle from where it is transported to the lungs for oxygenation. This oxygenated blood now comes to the left atrium and from here it is poured into the left ventricle. Therefore, the left part of the heart that is the left atrium and left ventricle contains the oxygenated blood.