Which of the following animals have scattered cells with cell - tissues grade organization ?
(a) Sponge
(b) Hydra
(c) Liver fluke
(d) Ascaris

Options

A. Sponge
B. Hydra
C. Liver fluke
D. Ascaris

Answer

To determine which of the following animals have scattered cells with a cell-tissue grade organization, we will analyze each option provided:

1. **Sponge (Porifera)**:
- Sponges are known for their cellular level of organization. They do not have true tissues; instead, their cells are loosely organized and perform various functions independently. Therefore, sponges do not fit the criteria of having a cell-tissue grade organization.

2. **Hydra (Cnidaria)**:
- Hydra exhibits a tissue level of organization. It is a multicellular organism with specialized cells that are arranged into tissues. These tissues are organized into layers, and the cells within these tissues can be considered scattered. This matches the criteria of having scattered cells with a cell-tissue grade organization. Thus, Hydra is a likely candidate.

3. **Liver Fluke (Trematoda)**:
- Liver flukes possess an organ-system level of organization. They have well-defined organs and systems, which means they do not fit the description of having a cell-tissue grade organization. Therefore, liver flukes are not the correct answer.

4. **Ascaris (Nematoda)**:
- Ascaris also has an organ-system level of organization. Similar to liver flukes, it has specialized organs and systems, which disqualifies it from being a candidate for the cell-tissue grade organization.

After evaluating all the options, we conclude that the correct answer is:

**(b) Hydra**