Vidaara.orgClass 8 · Mathematics
CodeVID-M8-WS
Respiration and Circulation — Practice Worksheet
Name: ____________________
Roll No.: __________
Date: ____________
General Instructions
- All questions are compulsory.
- Choose the correct option (A, B, C or D) for each question.
- The answer key is at the end — try the paper first!
Section A — Multiple Choice (1 mark each)
40 × 1 = 40 marks
1.
Cellular respiration mainly breaks down which food substance to release energy?
- A.Glucose
- B.Water
- C.Oxygen
- D.Vitamins
2.
The energy released in respiration is stored in molecules of:
- A.DNA
- B.ATP
- C.Chlorophyll
- D.Bile
3.
Aerobic respiration takes place in the presence of:
- A.Carbon dioxide
- B.Oxygen
- C.Nitrogen
- D.Sunlight
4.
The products of aerobic respiration are carbon dioxide, water, and:
- A.Glucose
- B.Energy (ATP)
- C.Oxygen
- D.Starch
5.
Most aerobic respiration occurs in the:
- A.Nucleus
- B.Mitochondria
- C.Vacuole
- D.Cell wall
6.
Anaerobic respiration is the breakdown of glucose:
- A.With plenty of oxygen
- B.Without oxygen
- C.Using sunlight
- D.In the nucleus
7.
Anaerobic respiration releases about how many ATP per glucose?
- A.38
- B.2
- C.100
- D.0
8.
Anaerobic respiration in human muscles produces:
- A.Alcohol
- B.Lactic acid
- C.Oxygen
- D.Glucose
9.
The products of anaerobic respiration in yeast are:
- A.Lactic acid only
- B.Ethanol and carbon dioxide
- C.Water and oxygen
- D.Glucose and oxygen
10.
The build-up of which substance causes muscle ache after hard exercise?
- A.Alcohol
- B.Lactic acid
- C.Glucose
- D.Bile
11.
As air passes through the nasal cavity, it is:
- A.Cooled and dried
- B.Warmed, moistened, and filtered
- C.Digested
- D.Turned into oxygen
12.
The windpipe, kept open by C-shaped cartilage rings, is the:
- A.Bronchus
- B.Trachea
- C.Alveolus
- D.Oesophagus
13.
The trachea divides into two tubes called:
- A.Alveoli
- B.Bronchi
- C.Bronchioles
- D.Villi
14.
Gas exchange in the lungs takes place in the:
- A.Bronchi
- B.Trachea
- C.Alveoli
- D.Nose
15.
When we breathe in, the diaphragm:
- A.Flattens (contracts)
- B.Rises into a dome
- C.Disappears
- D.Stops moving
16.
Gases are exchanged between the alveoli and blood by the process of:
- A.Active pumping
- B.Diffusion
- C.Digestion
- D.Filtration
17.
At the alveoli, oxygen moves:
- A.From blood into the air
- B.From the air into the blood
- C.In both directions equally
- D.Nowhere
18.
Diffusion of a gas takes place from a region of ______ to ______ partial pressure.
- A.Lower; higher
- B.Higher; lower
- C.Equal; equal
- D.Cold; hot
19.
Oxygen is carried in the blood mainly by:
- A.Plasma only
- B.Haemoglobin in red blood cells
- C.White blood cells
- D.Platelets
20.
Haemoglobin releases its oxygen mainly at the:
- A.Alveoli
- B.Body tissues (low oxygen)
- C.Trachea
- D.Nose
21.
The muscular organ that pumps blood around the body is the:
- A.Lung
- B.Heart
- C.Kidney
- D.Liver
22.
The human heart has how many chambers?
- A.Two
- B.Three
- C.Four
- D.Five
23.
The lower chambers of the heart that pump blood out are the:
- A.Atria
- B.Ventricles
- C.Valves
- D.Capillaries
24.
"Double circulation" means the blood passes through the heart:
- A.Once per circuit
- B.Twice per circuit
- C.Never
- D.Only at rest
25.
The circuit that carries blood from the heart to the lungs is the:
- A.Systemic circuit
- B.Pulmonary circuit
- C.Digestive circuit
- D.Lymphatic circuit
26.
The pale-yellow liquid part of blood that carries dissolved substances is:
- A.Plasma
- B.Haemoglobin
- C.Platelets
- D.Bile
27.
Which blood cells carry oxygen using haemoglobin?
- A.White blood cells
- B.Red blood cells
- C.Platelets
- D.Plasma cells
28.
The blood cells that defend the body against germs are the:
- A.Red blood cells
- B.White blood cells
- C.Platelets
- D.Plasma
29.
Platelets in the blood mainly help in:
- A.Carrying oxygen
- B.Clotting of blood
- C.Digesting food
- D.Producing hormones
30.
The four blood groups of the ABO system are:
- A.X, Y, Z, W
- B.A, B, AB, O
- C.Rh, Hb, Pl, Pl
- D.1, 2, 3, 4
31.
Blood vessels that carry blood away from the heart are:
- A.Veins
- B.Arteries
- C.Capillaries
- D.Valves
32.
Which blood vessels have valves to prevent backflow of blood?
- A.Arteries
- B.Veins
- C.Capillaries
- D.None
33.
The smallest blood vessels, with walls one cell thick, are:
- A.Arteries
- B.Veins
- C.Capillaries
- D.Bronchi
34.
Exchange of gases, food, and wastes between blood and cells occurs in the:
- A.Arteries
- B.Veins
- C.Capillaries
- D.Heart
35.
Compared with veins, arteries have walls that are:
- A.Thinner and weaker
- B.Thicker and more muscular
- C.The same
- D.Made of valves
36.
The pale fluid that drains from the tissues into lymph vessels is called:
- A.Plasma
- B.Lymph
- C.Bile
- D.Urine
37.
Small bean-shaped structures that filter lymph and trap germs are:
- A.Alveoli
- B.Lymph nodes
- C.Villi
- D.Nephrons
38.
Lymph is moved through the lymph vessels mainly by:
- A.The heart's pumping
- B.Squeezing of nearby muscles
- C.Gravity only
- D.Breathing only
39.
The lymphatic system is especially important for the body's:
- A.Digestion
- B.Immunity (defence)
- C.Breathing
- D.Eyesight
40.
Lymph nodes often swell when the body is:
- A.Resting
- B.Fighting an infection
- C.Sleeping
- D.Growing taller
Answer Key
Section A — Multiple Choice (1 mark each)
- (A) Glucose
- (B) ATP
- (B) Oxygen
- (B) Energy (ATP)
- (B) Mitochondria
- (B) Without oxygen
- (B) 2
- (B) Lactic acid
- (B) Ethanol and carbon dioxide
- (B) Lactic acid
- (B) Warmed, moistened, and filtered
- (B) Trachea
- (B) Bronchi
- (C) Alveoli
- (A) Flattens (contracts)
- (B) Diffusion
- (B) From the air into the blood
- (B) Higher; lower
- (B) Haemoglobin in red blood cells
- (B) Body tissues (low oxygen)
- (B) Heart
- (C) Four
- (B) Ventricles
- (B) Twice per circuit
- (B) Pulmonary circuit
- (A) Plasma
- (B) Red blood cells
- (B) White blood cells
- (B) Clotting of blood
- (B) A, B, AB, O
- (B) Arteries
- (B) Veins
- (C) Capillaries
- (C) Capillaries
- (B) Thicker and more muscular
- (B) Lymph
- (B) Lymph nodes
- (B) Squeezing of nearby muscles
- (B) Immunity (defence)
- (B) Fighting an infection
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