Class 8 English Literature – Extra Questions and Answers | Important Questions, Practice Questions and ICSE Study Material
Extra Question answers from the CHAPTER:
HUMAN BODY – THE CIRCULATORY SYSTEM
FULL
QUESTION PAPER (100 MARKS)
SECTION
A – OBJECTIVE TYPE (20 Marks)
A1.
Choose the correct option (10 × 1 = 10 marks)
a) A b) B c) AB d) O
2. The largest artery in the human body is the:
a) Pulmonary artery b) Aorta c) Coronary artery d) Renal artery
3. Which blood vessel carries blood towards the heart?
a) Artery b) Vein c) Capillary d) Aorta
4. The fluid matrix of blood is called:
a) Plasma b) Platelets c) RBC d) WBC
5. Which part of the heart pumps blood to the lungs?
a) Left atrium b) Left ventricle c) Right atrium d) Right ventricle
6. Blood vessels that connect arteries and veins are:
a) Veins b) Arteries c) Capillaries d) Aorta
7. Which valve is present between left atrium and left ventricle?
a) Tricuspid b) Bicuspid c) Semilunar d) Pulmonary
8. The normal heartbeat rate of an adult is about:
a) 50 bpm b) 72 bpm c) 100 bpm d) 120 bpm
9. Which system runs parallel to the circulatory system?
a) Nervous system b) Digestive system c) Lymphatic system d) Respiratory system
10. Blood without oxygen is called:
a) Oxygenated blood b) Deoxygenated blood c) Plasma d) Serum
A2.
Fill in the blanks (5 × 1 = 5 marks)
2. The heart works like a _________.
3. _________ cells fight against germs.
4. The largest vein is the _________.
5. Blood group _________ is universal recipient.
A3.
True or False (5 × 1 = 5 marks)
2. Capillaries are thick-walled vessels.
3. The heart has four chambers.
4. Platelets help in blood clotting.
5. Lymph is red in colour.
SECTION
B – SHORT ANSWERS (30 Marks)
B1.
Very short answers (6 × 2 = 12 marks)
2. Name the three types of blood vessels.
3. What is the function of haemoglobin?
4. What are valves?
5. What is pulse?
6. Name the four chambers of the heart.
B2.
Short answers (6 × 3 = 18 marks)
2. Differentiate between arteries and veins (any 3 points).
3. What is double circulation?
4. What is the role of white blood cells?
5. What is lymph? Write its function.
6. What is blood pressure?
SECTION
C – DIAGRAM & APPLICATION (20 Marks)
C1.
Diagram-based questions (10 marks)
2. Draw and label artery, vein and capillary. (5 marks)
C2.
Application-based questions (10 marks)
2. Why is double circulation important? (3 marks)
3. Why does a person feel tired when haemoglobin is low? (4 marks)
SECTION
D – LONG ANSWERS (30 Marks)
D1.
Answer the following (3 × 10 = 30 marks)
2. Explain the components of blood and their functions.
3. Explain ABO blood grouping system with table and explain universal donor and recipient.
SECTION
E – CASE STUDY / HOTS (10 Marks)
Read
and answer:
Ravi went
for a run and his heartbeat increased rapidly. After resting, it returned to
normal.
2. What is the normal heartbeat rate? (2 marks)
3. Which part of the heart controls heartbeat? (2 marks)
4. What is the advantage of increased heartbeat during exercise? (3 marks)
TOTAL = 100 MARKS
ANSWER KEY WITH FULL QUESTIONS
CHAPTER: HUMAN BODY – THE CIRCULATORY SYSTEM
SECTION A – OBJECTIVE TYPE
A1.
Choose the correct option
1.
Which blood group is called the universal donor?
a) A b) B c) AB d) O
Answer: d) O
2. The
largest artery in the human body is the:
a) Pulmonary artery b) Aorta c) Coronary artery d) Renal artery
Answer: b) Aorta
3.
Which blood vessel carries blood towards the heart?
a) Artery b) Vein c) Capillary d) Aorta
Answer: b) Vein
4. The
fluid matrix of blood is called:
a) Plasma b) Platelets c) RBC d) WBC
Answer: a) Plasma
5.
Which part of the heart pumps blood to the lungs?
a) Left atrium b) Left ventricle c) Right atrium d) Right ventricle
Answer: d) Right ventricle
6.
Blood vessels that connect arteries and veins are:
a) Veins b) Arteries c) Capillaries d) Aorta
Answer: c) Capillaries
7.
Which valve is present between left atrium and left ventricle?
a) Tricuspid b) Bicuspid c) Semilunar d) Pulmonary
Answer: b) Bicuspid
8. The
normal heartbeat rate of an adult is about:
a) 50 bpm b) 72 bpm c) 100 bpm d) 120 bpm
Answer: b) 72 bpm
9.
Which system runs parallel to the circulatory system?
a) Nervous system b) Digestive system c) Lymphatic system d) Respiratory system
Answer: c) Lymphatic system
10.
Blood without oxygen is called:
a) Oxygenated blood b) Deoxygenated blood c) Plasma d) Serum
Answer: b) Deoxygenated blood
A2. Fill in the blanks
1. The
_________ system transports materials in the body.
Answer: Circulatory
2. The
heart works like a _________.
Answer: Pump
3.
_________ cells fight against germs.
Answer: White blood cells
4. The
largest vein is the _________.
Answer: Vena cava
5.
Blood group _________ is universal recipient.
Answer: AB
A3. True or False
1.
Arteries carry blood towards the heart.
Answer: False
2.
Capillaries are thick-walled vessels.
Answer: False
3. The
heart has four chambers.
Answer: True
4.
Platelets help in blood clotting.
Answer: True
5.
Lymph is red in colour.
Answer: False
SECTION B – SHORT ANSWERS
B1.
Very short answers
1. What
is blood?
Answer: Blood is a fluid connective tissue that transports oxygen,
nutrients, and waste in the body.
2. Name
the three types of blood vessels.
Answer: Arteries, veins, and capillaries
3. What
is the function of haemoglobin?
Answer: It carries oxygen from lungs to body cells.
4. What
are valves?
Answer: Valves are structures that prevent the backflow of blood.
5. What
is pulse?
Answer: Pulse is the rhythmic expansion of arteries due to heartbeat.
6. Name
the four chambers of the heart.
Answer: Right atrium, left atrium, right ventricle, left ventricle
B2. Short answers
1.
Write any three functions of blood.
Answer:
Removes waste products
Maintains body temperature
2.
Differentiate between arteries and veins (any 3 points).
Answer:
|
Arteries |
Veins |
|
Carry
blood away from heart |
Carry
blood to heart |
|
Thick
walls |
Thin
walls |
|
No
valves |
Valves
present |
3. What
is double circulation?
Answer: Blood passes through the heart twice in one complete
cycle—pulmonary and systemic circulation.
4. What
is the role of white blood cells?
Answer: They fight germs and protect the body from infections.
5. What
is lymph? Write its function.
Answer: Lymph is a pale yellow fluid that transports nutrients and helps
fight infections.
6. What
is blood pressure?
Answer: It is the force of blood on the walls of arteries.
SECTION C – DIAGRAM &
APPLICATION
C1.
Diagram-based questions
1. Draw a neat labelled diagram of the human heart.
Answer:
2. Draw and label artery, vein and capillary.
Answer:
C2.
Application-based questions
1. Why
do veins have valves but arteries do not?
Answer: Veins have valves to prevent backflow because blood flows at low
pressure.
2. Why
is double circulation important?
Answer: It ensures efficient oxygen supply and prevents mixing of blood.
3. Why
does a person feel tired when haemoglobin is low?
Answer: Because less oxygen is transported to body cells.
SECTION D – LONG ANSWERS
1. Describe the structure and working of the human heart.
Answer:
Structure and Working of the Human Heart
The human
heart is a muscular, cone-shaped organ that acts as a pump to circulate
blood throughout the body. It is located in the chest cavity between the lungs
and slightly tilted to the left.
Structure
of the Heart
1.
Chambers of the Heart
The heart
has four chambers:
Right Ventricle – pumps deoxygenated blood to the lungs
Left Atrium – receives oxygenated blood from the lungs
Left Ventricle – pumps oxygenated blood to the whole body
The left
ventricle has the thickest muscular wall because it pumps blood to the
entire body.
2.
Septum
A thick
muscular wall called the septum divides the heart into left and right
halves, preventing mixing of oxygenated and deoxygenated blood.
3.
Valves of the Heart
Valves
ensure one-way flow of blood:
Bicuspid (Mitral) valve – between left atrium and left ventricle
Semilunar valves – at the openings of the pulmonary artery and aorta
4.
Major Blood Vessels
Pulmonary artery – carries blood from heart to lungs
Pulmonary veins – bring oxygenated blood to left atrium
Aorta – carries oxygenated blood to the body
Working
of the Heart (Double Circulation)
The heart
works in a rhythmic cycle called the cardiac cycle, involving
contraction (systole) and relaxation (diastole).
Step-by-step
process:
It flows into the right ventricle through the tricuspid valve
The right ventricle contracts and sends blood to the lungs via the pulmonary artery
In the lungs, blood gets oxygenated
Oxygenated blood returns to the left atrium through pulmonary veins
It passes into the left ventricle through the bicuspid valve
The left ventricle contracts and pumps blood to the whole body through the aorta
This process is called Double circulation because blood passes through the heart twice in one complete cycle.
2. Explain the components of blood and their functions.
Answer:
1.
Plasma
Plasma is
the liquid part of blood (about 55%).
Composition:
Proteins (albumin, globulin, fibrinogen)
Nutrients, hormones, salts, and waste products
Functions:
Maintains blood pressure and volume
Helps in clotting (due to fibrinogen)
Regulates body temperature and pH
2. Red
Blood Cells (RBCs) / Erythrocytes
These are
the most numerous cells in blood.
Features:
Contain hemoglobin
No nucleus (in humans)
Functions:
Carry carbon dioxide from tissues back to lungs
3.
White Blood Cells (WBCs) / Leukocytes
These are defense
cells of the body.
Types:
Functions:
Produce antibodies (especially lymphocytes)
Remove dead or damaged cells
4.
Platelets / Thrombocytes
These are small
cell fragments.
Functions:
Prevent excessive bleeding
Form a plug at injury sites
Explain ABO blood grouping system
with table and explain universal donor and recipient.
Answer:
ABO
Blood Grouping System
The ABO
blood grouping system classifies human blood based on the presence or
absence of antigens (A and B) on red blood cells and antibodies
in plasma.
Antibodies → found in plasma
A person’s
blood group depends on which antigen is present.
ABO
Blood Group Table
|
Blood
Group |
Antigen
on RBC |
Antibody
in Plasma |
Can
Donate To |
Can
Receive From |
|
A |
A |
Anti-B |
A, AB |
A, O |
|
B |
B |
Anti-A |
B, AB |
B, O |
|
AB |
A and B |
None |
AB |
A, B,
AB, O |
|
O |
None |
Anti-A
and Anti-B |
A, B,
AB, O |
O only |
Explanation
of Each Blood Group
Group B → Has B antigen and anti-A antibodies
Group AB → Has both A and B antigens, no antibodies
Group O → Has no antigens, but both antibodies
Universal
Donor
Reason: It has no A or B antigens, so it does not trigger an immune reaction in the recipient.
It can donate blood to all groups (A, B, AB, O).
Universal
Recipient
Reason: It has no anti-A or anti-B antibodies, so it can accept blood from all groups without reaction.
SECTION E – CASE STUDY
Ravi
went for a run and his heartbeat increased rapidly. After resting, it returned
to normal.
1. Why
did his heartbeat increase?
Answer: To supply more oxygen to the body during exercise.
2. What
is the normal heartbeat rate?
Answer: About 72 beats per minute
3.
Which part of the heart controls heartbeat?
Answer: Pacemaker (SAN)
4. What
is the advantage of increased heartbeat during exercise?
Answer: It increases oxygen supply and removes waste faster.