Maharashtra Board Class 8 Human Body and Organ System Textbook Exercises This page includes Fill in the Blanks, Questions and Answers, as well as Additional Questions and Answers for the chapter.
Fill in the blanks using appropriate words given in the bracket.
(hemoglobin, alkaline, diaphragm, red bone marrow, acidic, voluntary,involuntary,)
a. RBCs of the blood contain ———-, an iron compound.[hemoglobin]
b. ———- is present between thoracic and abdominal cavity.[Diaphragm ]
c. Cardiac muscles are ———-.[involuntary]
d. pH of oxygenated blood is ———-.[alkaline]
e. Production of RBCs occurs in ———-.[red bone marrow]
Complete the following table.
| Organ systems | Organs | Functions |
| Respiratory system | Nose, Pharynx, Larynx, Trachea, Bronchi, Lungs, Diaphragm | Inhalation (inspiration) and Exhalation (expiration)
Exchange of gases between blood
|
| Circulatory system
|
Heart, Blood Vessels (Arteries, Veins, Capillaries) Blood | Transport of oxygen, nutrients, hormones, and waste materials through blood vessels.
Exchange of gases in the Lungs. |
Explain with reasons.
a. Human blood is red coloured.
Human blood is red due to the presence of hemoglobin, an iron-containing protein in red blood cells (RBCs). Hemoglobin binds with oxygen, forming oxyhemoglobin, which gives the blood its red color.
b. Upward and downward movement of diaphragm occurs consecutively.
The diaphragm, a muscular organ found near abdominal cavities, plays a crucial role in breathing. During inhalation, the diaphragm contracts and moves downward, allowing air to enter the lungs. During exhalation, the diaphragm relaxes and moves upward, helps expel air from the lungs. This movement facilitates the process of breathing.
c. Blood donation is considered to be superior of all donations.
Blood donation is considered superior because it directly saves lives. Donated blood is used in medical treatments, surgeries, and emergencies to replace blood loss due to accidents, surgeries, or medical conditions.blood cannot be synthetically produced and relies on voluntary contributions from individuals.
d. Person with ‘O’ blood group is considered as ‘universal donor’.
Individuals with blood type ‘O’ are considered universal donors because their red blood cells lack A or B antigens on their surfaces. As a result, people with blood type ‘O’ can donate blood to individuals with any blood type (A, B, AB, or O) without triggering an immune response.
e. Food must have limited amount of salts.
An excessive intake of salt can lead to health issues such as high blood pressure and cardiovascular diseases. Therefore, it is recommended to consume salts in moderation.
Explain the differences.
a. Arteries and veins.
| Arteries | |
| Carry blood away from the heart. | Carry blood toward the heart. |
| carry oxygenated blood | Most carry deoxygenated blood |
| Have thicker, more muscular walls | Have thinner walls |
b. External and internal respiration.
| External | internal |
| Occurs in the respiratory system, specifically in the lungs. | Takes place in the body’s tissues and cells. |
| Involves the exchange of gases (oxygen and carbon dioxide) between the lungs and the external environment. | Involves the exchange of gases between the bloodstream and the body’s cells and tissues. |
| Oxygen is taken in from the air into the lungs, and carbon dioxide is expelled from the blood into the air in the lungs. | Oxygen is released from the blood to the cells, and carbon dioxide produced by cellular metabolism is taken up by the blood. |
Find odd one out.
a. A, O, K, AB, B.
Odd One: K – A, O, AB, and B are blood types (blood groups).
b. Blood plasma, platelets, blood transfusion, blood corpuscles.
Odd One: Blood transfusion
Blood plasma, platelets, and blood corpuscles are components of blood.Blood transfusion is a medical procedure involving the transfer of blood from one person to another; it is not a component of blood.
c. Trachea, alveoli, diaphragm, capillaries.
Odd One: Diaphragm
Trachea, alveoli, and capillaries are components of the respiratory system.
Diaphragm is a component of the respiratory system but plays a role in the process of breathing.
d. Neutrophils, globulins, albumins,prothrombin.
Odd One: Neutrophils
Globulins, albumins, and prothrombin are types of proteins found in blood plasma.
Neutrophils are a type of white blood cell (a cellular component of blood).
Maharashtra Board Class 8 Human Body and Organ System Extra QA
Q: What are the different organ systems in the human body?
A: Various organ systems in the body include digestive, respiratory, circulatory, nervous, excretory, reproductive, skeletal, and muscular systems.
Q: Where does energy production occur in cells, and what is needed for it?
A: Energy production occurs within cells. Cells require soluble nutrients and oxygen for energy production, supplied by the respiratory and circulatory systems.
Q: What are the three steps of respiration, and where does each step occur?
A: Respiration consists of external respiration (involving inspiration and expiration), internal respiration (exchange between cells and tissue fluid), and cellular respiration (glucose oxidation for energy).
Q: What is the role of the nose in respiration?
A: The nose, part of the respiratory system, filters air with hair and mucus. It is where respiration begins.
Q: Describe the structure and function of the heart.
A: The heart, a muscular organ, has four chambers (atria and ventricles) and continuously circulates blood through arteries and veins. Heartbeats are essential for blood circulation.
Q: What are the main types of blood vessels, and what are their functions?
A: Arteries carry blood away from the heart, veins carry blood toward the heart, and capillaries facilitate exchange of materials between blood and cells.
Q: What is blood pressure, and why is it important?
A: Blood pressure, exerted on artery walls during heart contraction, is crucial for proper blood circulation. Systolic pressure occurs during contraction, and diastolic pressure during relaxation.
Q: What are the main blood groups, and what is universal donor and recipient?
A: Blood groups include A, B, AB, and O, each with Rh-positive or Rh-negative. Person with blood group O is a universal donor, and AB is a universal recipient.
Q: Why is blood transfusion necessary, and where is blood collected and stored?
A: Blood transfusion is needed for various medical situations. Blood is collected in blood banks from donors, stored in refrigerators, and later supplied to those in need.
Q: What is hypertension, and what are normal blood pressure values?
A: Hypertension is high blood pressure. Normal blood pressure is around 120/80 mm Hg. Systolic pressure occurs during heart contraction, and diastolic pressure during relaxation.
