Question

Consider the following sentences I. Dentition is heterodont. II. Canines are poorly developed. III. Incisors are chisel like and poorly developed. IV. Herbivorous and diastema is present. V. The dental formula is,I 2/1; C 0/0; Pm 3/2; M 3/3. Which of the above are true for Oryctolagus?

• A. I, II, IV
• B. I, IV, V
• C. I, II, IV, V
• D. II, IV, V

Answer 1

Answer: (B)

I, IV, V

Answer 2

Oryctolagus cuniculus (rabbit) is commonly studied in the laboratory, because it is a good representative of class-Mammalia and is of fairly large size. Dentition in all the mammals are heterodont (ie, dissimilar teeth). Canineis one pointed in each maxillary of upper jaw and each dentary of lower jaw. In rabbit and other herbivorous mammals, canines are absent. Hence, some parts of gums between incisors and other teeth remain teeth less and called diastema. Rabbit possesses three pairs of sharp-chisel like incisors, two pairs in the premaxillaries of upper jaw and one pair in denteries of lower jaw. Dental formula of rabbit is:
$I\frac{2}{1},C\frac{0}{0}Pm\frac{3}{2}M\frac{3}{3}=\frac{8}{6}\times 2=28$