Animal Classification: Questions and Answers

Posted on Mar 30, 2025 in Biology

3) Progressive Changes in Animal Classification

Answer: Aristotle is known as the father of classification. Then came Carolus Linnaeus, who gave the two-kingdom classification: Plantae and Animalia. After this, Ernst Haeckel proposed the three-kingdom classification: Plantae, Animalia, and Protista. Later, Whittaker introduced the five-kingdom classification: Monera, Protista, Animalia, Fungi, and Plantae.

4) Grades of Organization vs. Symmetry

Answer: Grades of organization describe the types of cells, whether unicellular or multicellular. Different levels of grades of organization include:

• Tissue level organization (Porifera)
• Cellular level organization (Coelenterata)
• Organ level organization (Mollusca)

There are two types of symmetry:

1. Bilateral symmetry (e.g., prawn)
2. Radial symmetry (e.g., Hydra)

5) Brief Answers

a) Scientific Classification of Shark (Up to Class)

Answer: The shark’s classification is as follows:

• Kingdom: Animalia
• Phylum: Chordata
• Sub-phylum: Vertebrata
• Class: Pisces

b) Distinguishing Characters of Phylum Echinodermata

Answer: Characteristics of Echinodermata include:

• Calcareous spines are present, hence the name Echinodermata.
• Bilateral symmetry in larvae and radial symmetry in adults.
• Regeneration capabilities.

d) Phylum of Cockroach

Answer: The cockroach belongs to the phylum Arthropoda. This classification is based on the following characteristics:

• Jointed appendages are present.
• A chitinous exoskeleton covers the body.

6) Scientific Reasons

a) Tortoise Not Included in Class Amphibia

Answer: Although tortoises live on both land and in water, they possess characteristics specific to reptiles, not amphibians. These include dry, scaly skin, the presence of external ears, and a distinct neck, which are absent in amphibians.

b) Skin Irritation from Jellyfish Contact

Answer: Jellyfish possess cnidocytes (formerly known as endoblasts) containing nematocysts, which are toxic. Contact with skin causes irritation due to the injection of these toxins, serving as a protective mechanism for the jellyfish.

c) All Vertebrates are Chordates, But Not Vice Versa

Answer: During embryonic development, vertebrates possess a notochord, classifying them as chordates. However, in adult chordates, this notochord is replaced by a bony vertebral column.

e) Reptile Body Temperature Not Constant

Answer: Reptiles are cold-blooded (ectothermic) animals. Their internal body temperature fluctuates with the surrounding temperature. When the external temperature rises, their internal temperature also rises to balance, and vice versa.

7) Multiple Choice Questions

a) Special Cells in Sponges (Porifera)

Answer: 1) Collar cells.

b) Animal with Bilateral Symmetry

Answer: 3) Earthworm.

c) Animal Capable of Regeneration

Answer: 4) Starfish.

d) Class of Bat

Answer: 4) Mammalia.

e) Distinguishing Butterfly and Bat