Body cavity of Cockroach is called haemocoel because

Options

A. It contains blood
B. It contains lymph
C. It is filled with water
D. It is empty

Answer

To understand why the body cavity of a cockroach is called haemocoel, we can break down the explanation into clear steps:

### Step-by-Step Solution:

1. **Identify the Body Cavity**: The body cavity of the cockroach is referred to as the haemocoel. This term is specific to certain invertebrates, including arthropods like cockroaches.

**Hint**: Look for the terminology used in biology to describe body cavities in different organisms.

2. **Understand the Type of Body Cavity**: Cockroaches belong to the phylum Arthropoda, which are characterized by having a true body cavity known as a coelom. However, in cockroaches, this coelomic cavity is referred to as haemocoel.

**Hint**: Remember that the classification of body cavities can vary among different animal phyla.

3. **Examine the Vascular System**: Cockroaches possess an open circulatory system. This means that their blood (hemolymph) does not circulate within closed blood vessels like in vertebrates, but instead flows freely in the body cavity.

**Hint**: Consider how the circulatory system affects the classification of body cavities.

4. **Define Hemolymph**: The fluid within the haemocoel is called hemolymph, which consists of a colorless plasma and various cells. This fluid serves a similar function to blood in vertebrates, transporting nutrients and waste.

**Hint**: Think about the components of hemolymph and how they relate to the functions of blood.

5. **Conclusion**: The term "haemocoel" is derived from "haemo," meaning blood, indicating that this body cavity is filled with hemolymph (blood-like fluid). Therefore, the correct answer to the question is that the body cavity of the cockroach is called haemocoel because it contains blood (hemolymph).

**Hint**: Focus on the etymology of the term "haemocoel" to understand its meaning.

### Final Answer:
The body cavity of the cockroach is called haemocoel because it contains blood (hemolymph).