Transpiration
Plant use only 5% - 10% of the water, which is absorbed by the plant roots. Rest of the water is evaporated in the atmosphere through stomata. Evaporation of water through stomata is called transpiration. Transpiration actually helps in reducing pressure in the upper part of xylem. Reduction of pressure in the upper xylem pulls water in upward direction. Thus transpiration helps in water transportation.
Water is absorbed by the roots, which are in the lower part of the plant. This water needs to be transported to the leaves of the plant, which is in the upper part of the plant. For absorption of water from lower to the upper part a force is required. Plants perform a process to acquire this force and thus water reaches its upper side. Name the process.
(a) Translocation
(b) Transpiration
(c) Photosynthesis
(d) Respiration
(e) None of these
Answer: (b)
Sieve plates formed in the phloem tube because
(a) End walls of the phloem cells are not completely broken down and they have small holes
(b) Pits of phloem cells are not in contact
(c) Ends of the phloem cells are tapered
(d) End walls of the phloem cells are open
(e) None of these
Answer: (a) 
Transport System in Animals
Plants have evolved in such a way that their root system remains in contact with soil and shoot system remains in contact with atmosphere. Thus plants get all the required material from a single place and need not have to move. But animals have to move from place to place in order to get food and shelter. Movement in animals demands an improved transport system. When animals move fast, rate of their energy consumption increases by great extent. For the fast production of energy in the cells, cells required a fast transportation of required materials. Therefore, animal body requires a more efficient and evolved transport system, whose rate of transportation can be increased or decreased according to the body requirement. 
Transport System in Human Being
Human body also need a transport system as varieties of substances like oxygen, carbon dioxide, water, food, hormones, enzymes, etc. are needed to be transported form one part to another. In human being, the work of transportation is carried out by circulatory system. Circulatory system is made up of blood vessels and a heart.
Blood vessels are the tubular path through which blood keeps on circulating. There are three types of blood vessels, that is, arteries, veins, and capillaries. Together they form a net of blood vessels, which reaches every part of the body, making the blood to reach every parts. Blood, for reaching from heart to other parts of the body and for returning into heart from other parts of the body, use two different vessels system. The blood vessels called arteries are used by the blood to reach from heart to other parts of body .And the vessels called veins are used by the blood for coming back into heart from other parts of the body. Capillaries connect the arteries with veins. Thus blood vessels, by connecting with each other, form a tubular pathway through which blood could circulate throughout the body and can perform its functions. Blood rich in oxygen is called oxygenated blood and the blood rich in carbon dioxide is called deoxygenated blood. Arteries carry oxygenated blood and veins carry deoxygenated blood.
But one artery named pulmonary artery carries deoxygenated blood from heart to the lung and one vein name pulmonary vein carries oxygenated blood from lung to the heart.heart.
Blood
Vessels of the circulatory system are filled with a red colored fluid called blood. Blood inside the blood vessels keeps on circulating as a transport vehicle. It receives the substances from one part of the body and carries them to the required part of the body.
Blood are made up of four components plasma, RBC (Red blood corpuscles), WBC (White blood corpuscles), and platelets. RBC contains hemoglobin, which gives red colour to blood.
Functions of Blood
Blood performs the following functions:
(i) Blood supply all the required substances to the cells.
(ii) Blood carry the waste products out of body.
(iii) Blood maintain the body temperature at 37°c.
(iv) Blood contain the WBC, which is called the soldier of the body. WBC protects us from pathogens.
Heart
Blood keeps on moving continuously throughout the body in order to perform its functions. For the movement of blood a force is required. Therefore, human body has developed an organ, i.e. heart, specialized for producing force necessary for the movement of the blood. When heart expands, its internal volume is increased and larger amount of blood enters into it. When heart shrinks, the internal volume more... 
Lymphatic System
There is one more system that helps in the work of transportation, known as Lymphatic System.
Lymphatic system consists of lymph capillaries, lymph node and lymph. When blood passes through blood capillaries, blood plasma containing glucose and water leaks around the body cells through the walls of capillaries, since walls of capillaries are very thin. Here exchanges of substances occur between the cell and this leaked fluid (tissue fluid). The tissue fluid receives waste materials from the cells and seep back into blood capillaries. Tissue fluid also receives protein molecules, fragment of dead cells, germs etc., which cannot enter into blood capillaries because of their larger size. Therefore, they enter into lymph capillaries through the pores present in their wall. Lymph capillaries by joining together form lymph vessels. Lymph vessels contain lymph nodes, which have lymphocytes. Lymphocytes fight against the pathogens. Lymph contains, germs, fragments of dead cells, proteins etc. which can harm the body. Therefore, function of the lymph node is to clean the lymph and protect the body from diseases. Lymph capillaries reach this fluid into vein and thus liquids once again come in circulation.
Look at the following picture of human circulatory system
Lymph seeps back into lymph capillaries through..........
(a) Pores
(b) Close ends
(c) Open ends
(d) Blood capillaries
(e) None of these
Answer: (a)
Name the cells of the lymph node, which eats germs, fragment of dead cell etc. and helps in protecting the body from diseases
(a) RBC
(b) WBC
(c) Lymphocyte
(d) Antigens
(e) None of these
Answer: (c)
All the multicellular form of life needs a transport system for transportation of required material and for removing of waste materials.
In plants, xylem is responsible for transportation of water and minerals and phloem is responsible for transportation of food and hormones.
Xylem is made up of dead cells, whereas phloem is made up of living cells.
Evaporation of water through stomata is called transpiration.
Animals require more evolved form of transport system as they have to move from one place to another.
There are four components of blood. These are plasma, RBC, WBC, and platelets.
When pathogens enter our body, WBC of the blood kills them to protect us from the diseases.
Heart is specialized for producing movement in the blood.. 
Introduction
Often a question arises in our mind, why does our body take food, air and water? What does our body do with these substances? Our body takes food, water, and air to serve mainly the following purposes:
(a) To full fill the energy requirement of the body;
(b) For growth of the body;
(c) To repair the damaged parts of the body;
(d) To fight against the pathogens.
Respiration
Respiration can be termed as the production and utilization of energy. It fulfills the energy requirement of the living body. In winter days, you might have seen people burn woods to get heat energy to keep the body warm. Similarly our body burns glucose inside the cell to get energy, which is required to perform various functions. Our body performs many metabolic procedures. Each metabolic procedure requires energy to be performed. It is the respiration that supplies the required energy. Look at the following equation:
Glucose (Digested food) + Oxygen \[\to \] Carbon dioxide + Water + Energy
\[{{C}_{6}}{{H}_{12}}{{O}_{6}}+6{{O}_{2}}\to 6{{H}_{2}}O+6C{{O}_{2}}+\]
Energy The life appeared on the Earth about 3.8 billion year ago, when there was no oxygen \[({{O}_{2}})\] in the atmosphere. It is an evidence that early life could survive without oxygen. Some microorganisms have the ability to perform the respiration even in the absence of oxygen. On this basis, respiration has been classified into two types, which has been discussed below.
Types of Respirations
There are two types of respiration, aerobic respiration and anaerobic respiration. When digested food (glucose) is burnt in the presence of oxygen in order to obtain energy, it is called aerobic respiration. And when digested food (glucose) is burnt in the absence of oxygen in order to obtain energy, it is called anaerobic respiration.
Comparison between aerobic and anaerobic respiration
| Aerobic respiration | Anaerobic respiration |
| Respiration which is performed in the presence of oxygen | Respiration which is performed in the absence of oxygen |
| Production of more energy | Production of comparatively more...
 Human Respiratory System
As we know our body cells require oxygen for survival. Therefore, our body has evolved a tubular path so that oxygen can reach to the body cells from the atmosphere. This path (consists of many organ) is called respiratory path or respiratory system, as the path is specialized for respiration. This path begins from the nose and ultimately leads to the body cells through lungs and heart. Nose is an outer organ of respiratory system, which can be called as the gate of respiratory path, as air enters through it. It has been evolved in hollow tubular shape so that air can enter through it automatically. This air reaches the lungs through nasal cavity, pharynx and wind pipe, where it enters into another system called as circulatory system.
Circulatory system is a net of blood vessels, which are laid throughout the body so that each cell could be supplied with required nutrients and energy.
Blood acts as a transportation medium. It receives material from one part of the body and transports it to the required cells. Lungs contain a number of blood vessels and allow only oxygen to be entered into it from the air, which comes through respiratory path. Blood receives this oxygen and transport it to all the body cells. Blood supplies digested food from the small intestine to the cells also. Thus blood provides the cells with both fuel (glucose) and oxygen so that cells can perform their function and life can be continued. Cells burn this digested food (glucose) and get energy. In this process some unwanted products are also formed in the body, which may be harmful for the cells. Blood again receives those unwanted substances from the cells and expelled them out of body in reverse way.
Look at the Following Picture of Respiratory System in a Human Body
Let understand the whole process with the help of following points:
First, the air enters through nose or mouth into pharynx, as both nasal and oral cavity opens into it.
Pharynx leads to two path. One goes to lungs and another to the stomach, named wind pipe and food pipe respectively
Air enters into lung through wind pipe.
Lung acts as a junction of two systems, respiratory system and circulatory system, where respiratory gasses (carbon dioxide and oxygen) are exchanged from one to another system.
Only oxygen is allowed to enter into circulatory system (blood stream).
Blood receives the oxygen and enters into heart.
Heart pumps this blood throughout the body so that each cell can be supplied with oxygen.
Cells receive this oxygen and perform oxidation (burning of glucose).
Carbon dioxide produced during oxidation inside the cells are expelled into circulatory system.
Blood receives this carbon dioxide and reaches to the heart.
Heart pumps this blood to the lungs.
In lungs, \[C{{O}_{2}}\] enters into respiratory system from circulatory system.
Now this \[C{{O}_{2}}\] more...  Respiration in Plants
Plants have evolved themselves in such a manner that their every part may get air from atmosphere individually. Therefore, they do not need a respiratory system like animals. All parts of plants like roots, stem, and leaves perform respiration individually. Root has root hair for exchange of respiratory gasses. Root hairs lie in-between the soil particles, where air is trapped and receive air through the process of diffusion and send to the cells of root. Older plants have a pore called lenticels instead of root hair for exchanging respiratory gasses. Stem also have lenticels to get required air. Leaves have a pore on its lower surface called stomata through which exchange of respiratory gasses takes place.
Look at the Following Picture of Respiration in Plants
 Codi: Plants produce carbon dioxide during respiration
Jack: Only animals produce carbon dioxide
Who is correct?
(a) Codi
(b) Jack
(c) Both are correct
(d) Both are incorrect
(e) None of these
Answer: (a)
 Which one of the following is used by plant for exchanging respiratory gasses?
(a) Stomata
(b) Lenticels
(c) Root hair
(d) All of these
(e) None of these
Answer: (d)  Respiration in Animals
In respiration, oxidation of food inside the cell in almost all animals and plants are somewhat similar. But the transportation of respiratory gasses (\[{{O}_{2}}\]and\[C{{O}_{2}}\]), essential for respiration inside the cell and outside the cell, is different in different animals, as different animals live in different type of habitat. Therefore different animals have evolved different body shapes according to the environment they live in and to transport respiratory gasses from the environment. For example, earthworm lives in soil. So it has developed moist skin for the exchange of respiratory gasses. Fishes live in water and have to absorb oxygen dissolved in water. So they have developed gills for respiratory purpose. Land animals like human, dog, lion etc. have developed different respiratory system as they live on land. Hence, we see that different types of respiratory system have been evolved in different animals to suit their specific environment and for continuation of their life.
 Respiration and Photosynthesis
In photosynthesis, carbon dioxide and water is combined in the presence of sunlight to form glucose and oxygen .Whereas in respiration, glucose and oxygen is combined to form water and carbon dioxide. Input of energy from sunlight during photosynthesis is obtained in form of ATP molecules, during respiration. Living body cannot utilize sunlight directly. Therefore sunlight is required to be converted into simple form of energy so that it can be used by our body. In this whole process carbon, hydrogen and oxygen atoms act as a catalyst. They do not change; only their molecular arrangement is changed and sunlight is converted into simple form of energy.
To be alive, protection and energy are the first and basic requirement. And preparation of food is the first stage in the way of obtaining energy. It is the carbon, hydrogen and oxygen that make us enable to utilize the sunlight to get energy. Therefore these elements play very important role in sustaining life on the Earth. Without them we cease to exist.
 Which one of the following respiratory organs can receive oxygen dissolved in water?
(a) Lung
(b) Skin
(c) Gills
(d) Root hair
(e) None of these
Answer: (c)
 In which one of the following systems the lungs belong to?
(a) Digestive system
(b) Respiratory system
(c) Nervous system
(d) Excretory system
(e) None of these
Answer: (b)
Breathing consists of only two processes, i.e. inhaling of air and exhaling of air. Respiration consists of both breathing and oxidation of food. Therefore breathing is just a part of respiration.
Raw materials for more...  Structure of the Earth
The internal and outer structure of the Earth is layered. Denser and heavier materials (iron and nickel) are present in the core. The layer between the inner core and mantle is outer core. The outer core of the Earth is in liquid form and is composed of iron and nickel.
Look at the following picture of the Inner layer of the Earth
The mantle layer of the earth is mainly composed of elements like, magnesium, iron, silicon and oxygen. Temperature of the mantle layer is about 3000°C Outer mantle of the Earth is thinner than the inner mantle. The upper layer (crust) is made up of rocks, which are again made up of amino silicates.
The outermost layer of the Earth is called crust. The average thickness of the continental crust is about 30 to 50/km and mostly contains granite. The average thickness of the oceanic crust is about 10 km and mostly contains basalt.
Continental crust is formed by the movement and colliding of the plates.
 The distance between the Sun and the Earth is slightly varied during the year. Which one of the following is the cause of the distance variation?
(a) The earth is tilted
(b) Rotation of the earth
(c) Rotation of the other planet
(d) All of these
(e) None of these
Answer: (a)
Which one of the following is the most common cause of changing weather on the surface of the Earth?
(a) Distance between the earth and the moon
(b) Axial tilt
(c) Rotation of the earth
(d) Static state of the sun
(e) None of these
Answer: (b)  Soil Profile and Formation
Soil profile is the layer of soil on the surface of the Earth. The colour of the soil is dark brown. There are three soil profiles, namely. A, horizon, B horizon and C horizon. The upper layer of soil is called/^ horizon or top soil. A horizon provides nutrition to living organism. The layer below the A horizon, is B horizon. Horizon C is below the horizon B. Some part of minerals from horizon A is transported through horizon B to horizon C. There are various kinds of insects and bacteria that live on the soil and these are essential for plants.
The organic matter (humus) is found in the soil. Soil profile looks different in the different part of the earth.
Look at the following picture of the soil profile
Formation of Soil
Soil is made up of rocks and minerals. Weathering is the most common cause for the formation of the soil. The rocks on the surface of the Earth are broken down into small pieces by the process of the weathering. On the basis of the size of the rocks found on the surface of the earth, soil is categorized into three types. These are sand, silt and clay.
Look at the following picture of the soil
Sand is the larger particle found in soil. It is easily available on the surface of the earth. Sandy soil contains very little humus and of low fertility. The size of the particle of the sandy soil is bigger than that of particle size of the other soil.
The size of the particle of the silt soil is smaller than sands soil and bigger than clayey soil. Silt soil can easily transported from one place to another through the movement of the air.
Look at the following picture of the silt soil
The particle size of the clayey soil is very small. The formation of clayey soil is the gradual chemical weathering of rocks.
Look at the following picture of the clayey soil
 Which one of the following is the top most layer of the soil?
(a) Horizon B
(b) Horizon C
(c) Horizon D
(d) Horizon A
(e) None of these
Answer: (d)
Which one of the following types of soil contains least amount of humus?
(a) Sandy soil
(b) Clayey soil
(c) Loamy soil
(d) All of these
(e) None of these
Answer: (a) Current Affairs CategoriesArchive
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