Transportation In Animals And Plants - Class 7 Biology - Extra Questions

What are the upper chambers of the heart called? Are they the auricles or the atria?

The upper chambers of the heart are called auricles. They are also known as atria. Singular is an atrium. Human has two auricles and two ventricles. The left ventricle receives oxygenated blood from the lungs and the right ventricle receives deoxygenated blood from the tissues by vena cava.


Which chambers are the receiving chambers of the heart?

The human heart has four chambers: the two atria (right and left) and the two ventricles (right and left).
The Open Door Web Site : Biology : The Heart and Heart Disease
This is a diagram of the heart with the direction of blood flow (we can see from the diagram the RA and LA receive the blood). Among these chambers, the two atria receive blood from outside of the heart and the two ventricles propel blood from the heart to tissues. The right atrium receives blood from the superior and inferior vena cava. And the left atrium receives blood from the lungs through pulmonary veins. So, these two are called the receiving chambers of the heart.


What are the names of three layers of the heart wall?

The heart is a muscular organ that contracts rhythmically to pump blood through the circulatory system. Its walls consist of three tunics or layers, endocardium (internal layer), myocardium (middle layer), and pericardium (external layer).


What are the different cardiac muscle layer of the heart?

The human heart has three layers in its wall. They are, from inside outwards: endocardium, myocardium, and pericardium. Of these three layers, the endocardium is an endothelial lining. The myocardium is composed of cardiac muscle and the pericardium is the fibro-serous covering of the heart.


Arteries are the blood vessels that have elastic walls and _____ are the blood vessels with non-elastic thin walls.

Arteries are the blood vessels that have elastic walls and veins are the blood vessels with non-elastic thin walls.
 Arteries Veins
They carry oxygenated blood from the heart to all parts of the body.They carry deoxygenated blood from the body to the heart.
They have thick and elastic walls.They have thin and non-elastic walls.
The absence of valves is observed.Valves are present.
Reddish in appearance.Blueish in appearance.
 Pulse is detectable.Pulse is not detectable.


In human heart, blood passes through the heart twice during one cardiac cycle. This type of circulation is known as 

  • In human heart, blood passes through the heart twice during one cardiac cycle. 
  • The deoxygenated blood first comes to the heart through vena cava and goes to the lungs for oxygenation by pulmonary artery. 
  • Simultaneously, the oxygenated blood comes to the heart from lungs by pulmonary vein and goes to different organs through systemic aorta. Due to this. blood circulation in human heart is called double circulation. 



    Explain the flow of blood in heart.

    Both oxygen and carbon dioxide have to be transported by the blood, therefore, the heart has different chambers to prevent the oxygen-rich blood from mixing with the blood that contains carbon dioxide. The carbon dioxide-rich blood has to reach the lungs for the carbon dioxide to be removed, and the oxygenated blood from the lungs have to be brought back to the heart. This oxygen-rich blood is then pumped to the rest of the body.

    Oxygen-rich blood from the lungs comes to the left atrium. The left atrium relaxes when it is collecting this blood. It then contracts, while the next chamber, the left ventricle, relaxes so that the blood is transferred to it. When the left ventricle contracts, the blood is pumped out to the body.

    Deoxygenated blood comes from the body to the right atrium, as it relaxes. As the right atrium contracts, the corresponding lower chamber, the right ventricle, dilates. This transfers blood to the right ventricle, which in turn pumps it to the lungs for oxygenation. 



    John prepared stethoscope with paper cup and plastic tube. Write down the procedure of preparation.

    Procedure for preparation of stethoscope-
    • Take a small paper funnel of 6-7 cm in diameter. 
    • Fix a plastic tube (50 cm long) tightly on the stem of the funnel. 
    • Stretch a rubber sheet (or a balloon) on the mouth of the funnel and fix it tightly with a rubber band.
    • Put the open end of the tube on one of your ears.
    • Place the mouth of the funnel on chest near the heart.
    • Now, when listened carefully a regular thumping sound can be heard, which is called heartbeat.


    What are the components of blood?

    Explanation:

    There are four components of blood:
    (i) Plasma is a liquid part of blood that is yellowish in colour and contain 90% water. It contains food, enzymes, wastes and proteins etc.
    (ii) Red blood cells are disc-shaped cells containing red coloured pigment called haemoglobin. Haemoglobin helps in the transportation of oxygen.
    (iii) White blood cells are the fighting cells that protect us against bacteria and foreign materials causing infections.
    (iv) Platelets helps in clotting the blood.


    Very short answer type.
    What are the heart sounds heard through the stethoscope when placed on the chest? What produces them?

    Lub, Dub; Cardiac cycle.


    Name the organ which is located in the chest cavity with its lower tip slightly tilted towards the left. 

    The name of the organ is 'Heart'.
    The heart is a blood-pumping organ of the human circulatory system. 


    How do plants get nutrients?

    Explanation:
    • During the photosynthesis process, the green plants utilize the fresh materials in the existence of sunlight, and the outputs constructed are primarily glucose and water.
    • Glucose and starch are the fundamental foods needed by plants. Moreover, plants can immediately assimilate minerals and nutrients from the soil with the assistance of roots.
    Hence, plants get nutrients through this process.


    Name the component of blood which transports oxygen to different parts of the body.

    • One type of cells are the red blood cells (RBC) which contain a red pigment called haemoglobin. 
    • Haemoglobin binds with oxygen and transports it to all the parts of the body and ultimately to all the cells. It will be difficult to provide oxygen efficiently to all the cells of the body without haemoglobin. 
    • The presence of haemoglobin makes blood appear red. 


    What is blood? Describe the various components of blood.

    • Blood is the fluid which flows in blood vessels. It transports substances like digested food from the small intestine to the other parts of the body. It carries oxygen from the lungs to the cells of the body. It also transports waste for removal from the body.
    • It has four main components: plasma, red blood cells, white blood cells, and platelets.


    Why did the bleeding stop?

    Bleeding stopped after some time due to formation of blood clots. Blood clot is formed by Blood platelets.


    Observe the given figure and answer the given question.
    Name the instrument.

    1805292_fbe65796064f4dc4b3392093dd9c6bda.png

    Name of the given instrument is 'stethoscope'.
    It is an acoustic medical device used for listening to internal sounds of an animal or human body.


    Veins have valves which allow blood to flow only in one direction. Arteries do not have valves. Yet the blood flows in one direction only. Can you explain why? 

    The artery have thick elastic walls and arteries receives blood in high pressure directly from the left ventricle. Because of the high pressure flow of blood from the heart and the elasticity of the vessels, they blood flows only in one direction in arteries.


    Describe the following blood vessels: artery, vein and capillary.

    Blood vessels are tubular structures present throughout the body in which blood flows. There are three main types of blood vessels namely arteries, veins, and capillaries. 
    • Arteries carry blood from the heart to different parts of bodies. Blood here flows in high pressure, so they are thick-walled. All arteries except pulmonary artery carry oxygenated blood. 
    • Veins carry blood from different parts of the body to the heart. They are thin-walled than arteries. Except for the pulmonary vein, all veins carry deoxygenated blood.
    •  Capillaries are the fine branching blood vessels that form a network between the arteries and veins.


    Identify the system.

    The system depicted by the diagram is Urinary / Excretory system. 


    What are the smallest blood vessels in the human body?

    Capillaries are hollow tubular microscopic blood vessels 5 to 10 micrometers in diameter and having a wall one cell thick. They are the smallest blood vessels in the human body. They form a network between the arterioles and venules.
    1838985_1886729_ans_dce005ec19534d1a8c134b100b2b6dda.PNG


    Label all the parts. What is the fluid that accumulates in part 3? Which is the main nitrogenous waste present in it?

    1. Kidney
    2.Ureter
    3.Urinary bladder
    4.Bladder neck
    5.Urethra
    • The fluid that accumulates in part 3 is Urine.
    • The main nitrogenous waste present in it is urea. 


    Which is the main excretory organ in humans? 

    The main excretory organ in humans is a pair of kidneys. Blood contains both useful and harmful substances. The blood is filtered by the blood capillaries present in the kidneys. The useful substances are absorbed back into the blood and the waste substances are filtered out as urine.


    What would be the colour of the wounded area and why? 

    Dark red is the colour of wound. This is because of blood clotting caused by Blood platelets.


    Which type of blood cells are responsible for clotting of blood?

    Blood Platelets are responsible for blood clotting. 


    What is the advantage of having a four chambered heart?

    Four-chambered heart gives following advantages:
    (a) There is clear cut division of labour among different chambers. Atria receive blood and ventricles pump the blood.
    (b) There is complete segregation of oxygenated and deoxygenated blood in the heart.
    (c) Heart's efficiency is more in this design. 


    Very Short Answer.
    Write the main function of arteries and veins.

    Arteries transport oxygenated blood away from the heart to different parts of the body and veins bring the deoxygenated blood back to the heart.


    What is the function of cardiac muscles cells?

    The uninucleated, striated, tubular, and branched muscles that form the wall of the heart are known as cardiac muscles. They serve to bring about rhythmic contraction and relaxation of the heart to allow the pumping of blood throughout life. Since, these muscles contract without any nerve stimulation/control, they are involuntary in nature.


    Look at the figure. Draw another figure of the same set-up as would be observed after a few hours. 
    1805234_68e8f0975378433ea5e50dc1c38ba52b.png

    After a few hours, we see the increased level of sugar solution and decreased the level of water. This represents that water from the beaker has been absorbed by the solution. This happens because of the process of osmosis.
    1676074_1805234_ans_358415a85b2242648770e031431485d1.png


    Give the technical term for :-
    Instrument used to measure heartbeat.

    Sthethoscope.
    A stethoscope is an ​acoustic medical device for auscultation, or listening to the internal sounds of an animal or human body. It typically has a small disc-shaped resonator that is placed against the chest, and two tubes connected to earpieces. It is often used to listen to lung and heart sounds. It is also used to listen to intestines and blood flow in arteries and veins.


    Observe figure and answer the given questions: 
    Label the parts A, B and C. 

    1805297_9b600b79b71f420989dea5566f7d1bdc.png

    The diagram is of a stethoscope. 
    A - Diaphragm of the stethoscope that detects the sound from the chest.
    B - is the tube that transmits the sound to the earpieces.
    C - Earpieces help in hearing the sound from chest.

    1676289_1805297_ans_6d5b2ffd4d40438ba136082d3f19b0b4.png


    Class 7 Biology Extra Questions