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.
