Frogs: Habitat and Morphology
Meet Rana tigrina, the common Indian frog — a cold-blooded amphibian that divides its life between land and freshwater. This quiz tests your grasp of its habitat, physiology and external form: why it is called a poikilotherm, how camouflage and mimicry protect it, what aestivation and hibernation mean, and how its skin, colouration, body divisions, sense organs and limbs are built for a double life.
What you will practise
- Class and phylum of frogs, and the identity of Rana tigrina
- Poikilothermy, camouflage and the two forms of dormancy
- Skin texture, mucus and water absorption
- Dorsal and ventral colouration
- Body divisions, nictitating membrane and tympanum
- Limbs, digits, webbing and sexual dimorphism
Tip: Read each option carefully — several choices are true statements about frogs but do not answer the question asked.
Q1. Frogs belong to which class and phylum?
The lesson states that frogs belong to class Amphibia of phylum Chordata, a group whose name reflects their two modes of existence.
Q2. Which species is described as the most common frog found in India?
The lesson explicitly names Rana tigrina as the most common species of frog found in India and uses it as the representative vertebrate.
Q3. Frogs are called poikilotherms because:
Poikilotherms, or cold-blooded animals, do not have a constant body temperature; it varies with the surrounding temperature.
Q4. Which pair of animals is described in the lesson as warm blooded, in contrast to the frog?
The lesson contrasts the frog with birds and mammals, which maintain a steady internal temperature and are described as warm blooded.
Q5. The ability of a frog to change colour so as to hide from its enemies is called:
The lesson states that frogs can change colour to hide from enemies, and this protective coloration is called camouflage (referred to as mimicry).
Q6. In the lesson, the protective coloration of the frog is specifically termed:
The lesson says: "This protective coloration is called mimicry." Camouflage is the act of hiding; the protective coloration itself is termed mimicry.
Q7. Frogs are not seen during peak summer because they:
During peak summer frogs take shelter in deep burrows to escape extreme heat; this summer sleep is called aestivation.
Q8. Winter sleep in frogs, during which they shelter in deep burrows, is known as:
The lesson defines winter sleep as hibernation, while summer sleep is aestivation. Both involve sheltering in deep burrows.
Q9. The skin of a frog is smooth and slippery because of the presence of:
The lesson states that the skin is smooth and slippery due to mucus, and is always maintained in a moist condition.
Q10. How does a frog obtain water, according to the lesson?
The lesson notes that the frog never drinks water but absorbs it through the skin, which is kept moist by mucus.
Q11. The dorsal side of a frog's body is generally:
The dorsal side is generally olive green with dark irregular spots, while the ventral side is uniformly pale yellow.
Q12. The body of a frog is divisible into:
The lesson states the body is divisible into head and trunk, and that a neck and tail are absent.
Q13. The nictitating membrane in a frog:
The eyes are bulged and covered by a nictitating membrane that protects them while the frog is in water.
Q14. Which statement about the limbs and digits of a frog is correct?
The hind limbs end in five digits and are larger and muscular than the forelimbs, which end in four digits. Webbed feet help in swimming.
Q15. Male frogs can be distinguished from female frogs by the presence of:
Frogs exhibit sexual dimorphism: males have sound-producing vocal sacs and a copulatory pad on the first digit of the forelimbs, both absent in females.