I. Rattus rattus. Il. Agama agama III. Bufo regularis IV. Tilapia  zillii The order of evolutionary advancement of the above vertebrates is?

Analyze the question

You are asked to arrange four vertebrates from the least advanced (earliest evolved) to the most advanced. First identify each animal:

• I. Rattus rattus is the black rat, a mammal.
• II. Agama agama is the rainbow lizard, a reptile.
• III. Bufo regularis is the common African toad, an amphibian.
• IV. Tilapia zillii is a freshwater fish, a fish (class Pisces).

Concept

Vertebrates evolved in this order:

Fish → Amphibians → Reptiles → Birds/Mammals

• Fish were the first vertebrates. They live in water and breathe with gills.
• Amphibians moved onto land but still depend on water for breeding.
• Reptiles have dry, scaly skin and lay shelled eggs, so they are fully adapted to land.
• Mammals are the most advanced. They have hair, mammary glands, a diaphragm, and a four-chambered heart.

Solution

Ordering from least to most advanced:

1. Tilapia zillii (IV), the fish
2. Bufo regularis (III), the amphibian
3. Agama agama (II), the reptile
4. Rattus rattus (I), the mammal

The order is IV, III, II, I, which matches option D.

Answer: D

Tip: Remember the sequence with "FARM": Fish, Amphibians, Reptiles, Mammals. When a question lists species, first identify each one's class, then apply FARM. Also check whether the question asks for "least to most advanced" or the reverse, because the options often include both directions.