Morphology of Frog Questions in English

(A) The $Frog$ plays a crucial role in maintaining ecological balance. It serves as an important link in the food chain and food web within the ecosystem. By acting as both a predator (consuming insects) and prey (for larger animals like snakes and birds), it helps regulate insect populations and supports biodiversity.

(B) In frogs,the forelimbs and hindlimbs are attached to the trunk. The forelimb consists of the proximal upper arm,the middle forearm,the wrist,and a hand bearing four digits (fingers). The hindlimb consists of the proximal thigh,the middle shank,a long ankle,and a foot bearing five digits (toes). Therefore,the statement that forelimbs end in five digits is incorrect.

(D) In frogs,various sense organs are present to perceive the environment.
Sensory papillae are specialized structures associated with the sense of touch.
Taste buds are responsible for taste,the nasal epithelium is for smell,eyes are for vision,and the tympanum with internal ears is for hearing.

(D) The skin of a frog is smooth and slippery because it is always maintained in a moist condition by the presence of mucus.
It is the primary site for cutaneous respiration,and the frog also absorbs water through its skin.
The dorsal side of the frog is generally olive green with irregular dark spots,while the ventral side is uniformly pale yellow.
Therefore,all the given statements are correct.

(B) In the given diagram of a frog:
$P$ represents the external nostril.
$Q$ represents the eye,which is protected by a nictitating membrane.
$R$ represents the forelimb.
$S$ represents the hindlimb.
The nictitating membrane is a transparent,movable eyelid that protects the eye of the frog while it is underwater. Therefore,the correct label is $Q$.

(D) In male frogs,the copulatory pad (also known as the nuptial pad) is a specialized structure found on the ventral side of the first digit of the forelimb. This pad helps the male in clasping the female during the process of amplexus (mating). Therefore,the correct location is the first digit of the forelimb.

(B) Frogs protect themselves from enemies primarily through a phenomenon known as camouflage (also called cryptic coloration).
This allows them to blend into their surroundings,making them difficult for predators to detect.
Frogs do not use their teeth for defense,as their teeth are primarily used for holding prey rather than biting enemies.
They also lack claws on their digits,which further rules out option $(C)$.
Therefore,the correct mechanism for protection is camouflage.

(D) In male frogs,the nuptial pad (also known as the thumb pad) is a specialized glandular structure found on the ventral side of the first digit of the forelimb.
This structure develops during the breeding season and is used to grasp the female frog during the process of amplexus (mating).
Therefore,the correct location is the first digit of the male frog.

(D) The correct answer is $D$.
Frogs and toads are both amphibians belonging to the order $Anura$.
They can be differentiated by several morphological features:
$1$. Frogs typically have smooth,moist skin,while toads have dry,warty skin.
$2$. Frogs have long,powerful hind legs for jumping,whereas toads have shorter legs and tend to walk or hop.
$3$. The most distinct anatomical difference is that toads possess a pair of large,prominent parotid glands behind their eyes,which secrete toxins for defense,whereas frogs lack these specific glands.

(C) Male frogs can be distinguished from female frogs by the presence of specific secondary sexual characteristics.
$1$. Vocal sacs $(B)$: These are present in male frogs and help in producing loud croaking sounds to attract females.
$2$. Copulatory (nuptial) pads $(D)$: These are present on the first digit of the forelimbs in male frogs and are used to grip the female during the process of amplexus (mating).
Therefore,the correct combination is $B$ and $D$.