Question

Observe the following simplified scheme and choose the correct option that matches with the letters given in the boxes.

• A. p-Agnatha, q- Gnathostomata, r-Pisces, s-Tetrapoda
• B. p- Gnathostomata, q- Agnatha, r-Tetrapoda, s- Pisces
• C. p-Tetrapoda, q- Pisces, r- Gnathostomata, s - Agnatha
• D. p- Agnatha, q- Gnathostomata, r-Tetrapoda, s - Pisces

Answer 1

The Correct Option is A

p (Lacks Jaw) refers to Agnatha, which are jawless vertebrates (e.g., lampreys and hagfish). 

q (Bears Jaw) refers to Gnathostomata, which are jawed vertebrates (e.g., fish, amphibians, reptiles, birds, and mammals). 

r (Bear fins) refers to Pisces, which are fish (aquatic vertebrates with fins). 

s (Bear limbs) refers to Tetrapoda, which are vertebrates that have four limbs (e.g., amphibians, reptiles, birds, and mammals).

The correct answer is (A) :p-Agnatha, q- Gnathostomata, r-Pisces, s-Tetrapoda

Answer 2

p - Agnatha: Agnatha are jawless fish (lacks jaw). 
q - Gnathostomata: Gnathostomata are vertebrates with jaws (bears jaw). This large group then splits into those with fins and those with limbs. 
r - Pisces: Pisces are fish and have fins (bear fins). 
s - Tetrapoda: Tetrapoda are four-limbed vertebrates (bear limbs).

The correct answer is (A) :p-Agnatha, q- Gnathostomata, r-Pisces, s-Tetrapoda