Question

Explain the basis of grouping organisms into chordata and non chordata

Answer 1

The organisms of kingdom animalia is divided into chordata and non-chordata based on the presence of notochords, so chordates are the organisms which have notochords while non-chordates are the organisms which don't have notochords.

Answer 2

Answer:

Difference # Chordates:

1. A notochord is present at some stage in the life of a chordate.

2. Central nervous system is dorsal and hollow.

3. Gill slits are present in the pharynx either in the embryo or adult.

4. Tail is present at some stage in the life of the chordate.

5. Heart is ventral.

6. If present RBCs contain respiratory pigment (haemoglobin).

Difference # Non-chordates:

1. Notochord is not present at any stage in the life of a non-chordate.

2. Central nervous system is ventral and solid.

3. Gill slits are absent.

4. Tail is absent.

5. Heart is dorsal (if present).

6. If haemoglobin or other respiratory pigment is present, it is found in the blood plasma. RBCs are absent.