Examkin

Question

Difficulty: MediumCirculatory and Transport Systems in Animals

Which of the following statements correctly differentiates the circulatory pathway of a bony fish from that of a mammal?

  1. In a bony fish, blood flows through the heart only once during a complete circuit, whereas in a mammal, blood flows through the heart twice.Answer
  2. B
    In a bony fish, oxygenated blood returning from the respiratory organ enters the heart before being pumped to systemic tissues.
  3. C
    A bony fish possesses a three-chambered heart that prevents the mixing of oxygenated and deoxygenated blood.
  4. D
    In a mammal, deoxygenated blood returning from systemic tissues enters the left atrium first.

Answer

In a bony fish, blood flows through the heart only once during a complete circuit, whereas in a mammal, blood flows through the heart twice.
Bony fish exhibit single circulation with a two-chambered heart, meaning blood passes through the heart only once per complete journey around the body. Mammals exhibit double circulation with a four-chambered heart, meaning blood passes through the heart twice per complete circuit.

Step-by-Step Solution

1
Analyze the circulatory pattern of Pisces (bony fish).
Fish have a single-circuit circulation powered by a two-chambered heart (one atrium and one ventricle). Deoxygenated blood is pumped from the ventricle to the gills, becomes oxygenated, and continues straight to body tissues.
Understanding single circulation clarifies how blood moves through fish heart chambers.
2
Analyze the circulatory pattern of Mammalia (mammals).
Mammals have a double-circuit circulation powered by a four-chambered heart. Blood passes through the right side of the heart to the lungs (pulmonary circuit), returns to the left side of the heart, and is pumped to body tissues (systemic circuit).
Comparing single versus double circulation highlights the fundamental physiological difference.
3
Match the comparative analysis to the correct option.
The statement highlighting single flow through the heart in fish versus double flow in mammals accurately reflects vertebrate circulatory evolution.
Identifies the correct physiological distinction.

Key Concept

Single versus Double Circulation in Vertebrates
Rate this question

Topics

Circulatory and Transport Systems in Animals

More questions from this topic