Match chambers of heart with different creatures

Match the following (Heart chambers)

1. Two chambered –           1. Aves
2. Three chambered –           2. Fishes
3. Four chambered –           3. Amphibians
4. Incomplete four chambered – 4. Reptiles

(A) 2, 3, 1, 4

(B) 2, 1, 3, 4

(C) 1, 2, 3, 4

(D) 4, 2, 1, 3

EXPLANATION

Two-Chambered Heart → Fishes (2)

• Structure:

  • 1 atrium

  • 1 ventricle

• Function:

  • Blood flows in a single circuit: heart → gills → body → heart.

• Why:

  • Since fish live in water and breathe using gills, their simpler circulatory system is sufficient.

• ✅ So, fishes have a two-chambered heart.

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2. Three-Chambered Heart → Amphibians (3)

• Structure:

  • 2 atria

  • 1 ventricle

• Function:

  • Blood from lungs and body enters different atria, but mixes in the single ventricle.

  • This is called incomplete double circulation.

• Why:

  • Amphibians (like frogs) live both on land and in water, so they need lungs and skin for breathing.

• ✅ So, amphibians have a three-chambered heart.

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3. Incomplete Four-Chambered Heart → Reptiles (4)

• Structure:

  • 2 atria

  • Ventricle is partially divided (not fully separated).

• Function:

  • Some mixing of oxygenated and deoxygenated blood still occurs.

• Exception:

  • Crocodiles are an exception — they have a fully four-chambered heart, but with a special shunt system.

• ✅ So, most reptiles have an incomplete four-chambered heart.

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4. Four-Chambered Heart → Aves (Birds) (1)

• Structure:

  • 2 atria

  • 2 ventricles

• Function:

  • Complete separation of oxygen-rich and oxygen-poor blood.

• Why:

  • Birds have a very high metabolic rate, especially for flight, and need efficient oxygen circulation.

• ✅ So, birds have a fully four-chambered heart.

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✅ Final Matching Recap:

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✅ Correct Answer: (A) 2, 3, 1, 4