Transportation in Animals and Plants Class 7 Notes Science Chapter 7

Class 7 Science Chapter 7 Notes Transportation in Animals and Plants

→ Ammonia : It is a colourless gas, having a strong pungent order. It is highly soluble in water and alcohol.

→ Artery : Artery is the blood vessel which carries oxygen rich blood from the heart to all parts of the body.

→ Blood : It is a fluid connective tissue which transport various essential substances to the body and having various types of cells such as RBCs.WBCs and platelets.

Transportation in Animals and Plants Class 7 Notes Science Chapter 7

→ Blood vessels : Blood vessels are tubes or pipes that carry blood throughout the body. It runs between the heart and the rest of the body.

→ Capillaries : Capillaries are very thin blood cells that form a network between arteries and veins.

→ Circulatory System: Various organs and tissues involved in circulating blood and lymph throughout the body is called circulatory system.

→ Dialysis : The process used for cleaning the blood of a person by separating the waste product urea from it is called dialysis.

→ Excretion : The process of removal of waste materials produced in the cells of the living organism is called excretion.

Transportation in Animals and Plants Class 7 Notes Science Chapter 7

→ Excretory system : The system of an organism’s body that performs the function A excretion is called excretory system. It consists of two kidneys, two ureters, a urinary bladder and a urethra.

→ Haemoglobin : Haemoglobin is a red protein that binds with oxygen and transports oxygen to all the parts of the body and ultimately to all the cells.

→ Heartbeat : The rhythmic contraction and expansion of the heart muscle is called heartbeat.

→ Kidney : It is either of the two bean shaped excretory organs that filter the blood to eliminate the nitrogenous waste is from it.

→ Phloem : It is a vascular tissue in plant which transports the produced food from leaves to all parts of the body.

→ Platelets : Platelets are very small disc shaped cells present in the blood. They help to clot the blood from a cut or wound.

→ Pulse : It is the rate at which heartbeat.

→ Red blood cells : Red blood cells are disc shaped, biconcave cell in the blood that contains haemoglobin, lacks a nucleus and transports oxygen and carbon dioxide to and from the tissues.

→ Root hair : Plant roots have like structures called root hair. They could be considered as cluster very fine, delicate, thread like structures.

Transportation in Animals and Plants Class 7 Notes Science Chapter 7

→ Stethoscope : It is an instrument mostly used by the doctors to feel the heartbeat of a person.

→ Sweat : A salty fluid released through small pores on the skin is called sweat. Sweat is secreted by sweat glands.

→ Tissue : A group of cells similar in structure that perform a specific function is called a tissue.

→ Urea : A nitrogen containing colourless and crystalline compound produced in the body of mammals as a result of breakdown of proteins is known as urea. It is excreted out from the body through urine.

→ Ureter: Athin muscular tube that transports urine from kidney tourinary bladder.

→ Urethra : It is a duct through which urine is discharged in most mammals.

→ Uric acid : It is a white tasteless, odourless crystalline product of protein metabolism. It is the main excretory product in birds, reptiles and insects.

→ Urinary bladder : A membranous sac for temporary retention of urine is called urinary bladder.

→ Vein : It is a blood vessel that carries blood rich in carbon dioxide from the capillaries towards the heart.

→ White blood cells : It is colourless cells in the blood that have a nucleus and cytoplasm. They are very important parts of the body’s defence system.

Transportation in Animals and Plants Class 7 Notes Science Chapter 7

→ Xylem : A vascular tissue present in the plants for the transportation of water and nutrients in the plants is called xylem.

→ Vascular system or transport system in flowering plants is composed of pipe-like vessels called xylem and phloem.

→ Osmosis is the process of movement of water through a semi-permeable membrane from an area of higher concentration to an area of lower concentration.

  • Water is absorbed by the roots from the soil by this process.
  • Water molecules are more crowded outside the root hair hence, they move into the root via root hairs by the process of osmosis.

→ The upward movement of water and minerals in plants through the xylem vessels is called ascent of sap.

  • The sap contains water and dissolved minerals absorbed by the roots from the soil.

→ The transportation of food prepared by the leaves to all’parts of the plant is called translocation.

→ Drooping down of leaves, stems and flowers of a plant due to excessive loss of water is. called wilting.

  • It mainly occurs due to excessive loss of water from the plant leaves through transpiration.

→ The transportation of nutrients in unicellular organisms such as Amoeba, Paramecium, etc., takes place by the process of diffusion.

Transportation in Animals and Plants Class 7 Notes Science Chapter 7

→ The volume of blood in an adult human is about 4-5 litres.

Blood can transport :

  • Digested food from small intestine to all other parts of the body.
  • Oxygen from lungs to different cells in the body.
  • Carbon dioxide from cells to lungs.
  • Metabolic waste products from cells to the kidneys.

→ Plasma is the liquid part of the blood which is pale yellow in colour and contains about 90% of water. It contains food materials, wastes, enzymes, etc., dissolved in it.

→ Red blood cells (RBCs) or erythrocytes are the most abundant cells in human body.

Haemoglobin is a red pigment present in RBCs of blood.

  • It can combine with oxygen to form a compound called oxyhaemoglobin.
  • On reaching the cells, oxyhaemoglobin breaks down into oxygen and haemoglobin.
  • Oxygen, thus, released is used by the cells for respiration and haemoglobin be¬comes free to carry more oxygen.

→  White blood cells (WBCs) are larger than red blood cells (RBCs) and are fewer in number. They are able to move on their own and hence, are able to pass through the walls of blood vessels and reach the infected parts of the body. They are also called leucocytes.

→ Platelets or thrombocytes are smaller in size than both RBCs and WBCs. During an injury, they block the flow of blood and prevent blood loss.

Transportation in Animals and Plants Class 7 Notes Science Chapter 7

→ Blood vessels are a network of tubes through which blood circulates across the body.

→ Capillaries are the thinnest blood vessels and have thin walls through which oxygen, digested food, carbon dioxide and other waste products are exchanged between the blood and the surrounding cells.

→ Auricles are the two upper chambers of the human heart which have comparatively thinner walls.

→ Ventricles are the two lower chambers of the human heart which have thick muscular walls.

→ Septum is a muscular partition that separates right side of the heart from its left side. It prevents the mixing up of oxygenated and deoxygenated blood in the heart.

→ Valves are present in the heart. They prevent backflow of blood inside the heart.

→ An instrument to measure the blood pressure is called sphygmomanometer.

→ The heart sound, lub-dub, is produced by the closing of valves in the heart when contractions in the ventricles and auricles occitr.

→ Pulse is the throbbing felt at the wrist dire to the stretching and relaxing of the arteries with each heartbeat.

→ Blood pressure is the pressure exerted by the circulating blood on the walls of the arteries.

→ Cellular reactions taking place in the body during life activities such as respiration, digestion, etc., are called metabolism.

→ In lower animals, such as Amoeba, Paramecium, Hydra and sponges, excretory’ or¬gans are absent and thus, excretion takes place by the process of diffusion through their body surface.

→ Nephrons are tiny filtering units of the kidney. Each kidney consists of about one million nephrons.

Transportation in Animals and Plants Class 7 Notes Science Chapter 7

→ Besides the kidneys, our skin also helps in the removal of wastes such as’excess of water, urea, salts and other metabolic wastes in the form of sweat. Sweat glands are present in our skin.

→ Dialysis is the artificial method of removal of toxic substances from the blood of a patient with kidney damage or failure with the help of artificial kidneys.

→ Diffusion is the process of movement of molecules or gases from a region of higher concentration to a region of lower concentration.

Class 7 Science Notes

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