Consider the following statements regarding the protective coloration and behavior of frogs:
I. Frogs can change their skin color while in grasses or on dry land. II. The ability to change color to hide from enemies is called camouflage. III. This protective coloration is referred to as mimicry. IV. Camouflage is mainly used by frogs to attract prey rather than to hide from predators.
Explanation: Statements I, II and III are correct because frogs change colour for camouflage, which is a form of protective mimicry. Statement IV is incorrect because camouflage primarily protects frogs from predators rather than attracting prey.
Question 42 of 101
📘 CLASS XI
Analyze the statements regarding seasonal sleep in frogs:
I. Frogs are highly active during peak summer and winter, feeding continuously. II. During extreme temperatures, frogs take shelter in deep burrows. III. Summer sleep is called hibernation, while winter sleep is called aestivation. IV. Summer sleep is called aestivation, while winter sleep is called hibernation.
Explanation: Statement I is incorrect because frogs remain dormant during extreme summer and winter. Statement II is correct because they take shelter in deep burrows. Statement III is incorrect because the terms are reversed. Statement IV is correct because aestivation occurs during summer and hibernation occurs during winter.
Question 43 of 101
📘 CLASS XI
Consider the following statements regarding the morphology of the frog's skin:
I. The skin of the frog is dry and rough to prevent water loss on land. II. Skin is smooth and slippery due to the presence of mucus. III. The dorsal side is olive green with dark irregular spots, while the ventral side is uniformly pale yellow. IV. The frog drinks large quantities of water through its mouth to stay hydrated.
Explanation: Statement I is incorrect because frog skin is smooth, moist and slippery. Statements II and III are correct because mucus keeps the skin moist and the dorsal and ventral colouration matches the textbook description. Statement IV is incorrect because frogs absorb water through their skin instead of drinking it.
Question 44 of 101
📘 CLASS XI
Analyze the structural characteristics of the frog's body divisions and head:
I. The body of a frog is divided into head, neck, and trunk. II. A neck and tail are absent in adult frogs. III. A pair of nostrils is present above the mouth. IV. Bulged eyes are covered by a nictitating membrane that protects them in water.
Explanation: Statement I is incorrect because the adult frog body is divided only into head and trunk. Statements II, III and IV are correct because adults lack a neck and tail, nostrils lie above the mouth, and the eyes are protected by a nictitating membrane.
Question 45 of 101
📘 CLASS XI
Consider the following statements regarding the limbs of frogs:
I. Forelimbs and hind limbs assist in swimming, walking, leaping, and burrowing. II. Forelimbs are larger and more muscular than hind limbs. III. Hind limbs end in five digits, while forelimbs end in four digits. IV. Feet have webbed digits that facilitate swimming.
Explanation: Statements I, III and IV are correct because frog limbs are adapted for locomotion and swimming. Statement II is incorrect because the hind limbs are larger and more muscular than the forelimbs.
Question 46 of 101
📘 CLASS XI
Consider the following statements regarding sexual dimorphism in frogs:
I. Female frogs can be distinguished by sound-producing vocal sacs. II. Male frogs possess sound-producing vocal sacs. III. Male frogs have a copulatory pad on the first digit of the forelimbs. IV. Both vocal sacs and copulatory pads are completely absent in female frogs.
Explanation: Statement I is incorrect because vocal sacs are present only in males. Statements II, III and IV are correct because male frogs possess vocal sacs and copulatory pads, both of which are absent in females.
Question 47 of 101
📘 CLASS XI
Analyze the statements regarding the general anatomy of the frog's digestive canal:
I. The alimentary canal is short because frogs are carnivores. II. The length of the intestine is reduced in carnivores like frogs. III. The short oesophagus opens directly into the duodenum, bypassing the stomach. IV. The stomach continues as the intestine, rectum, and finally opens to the outside via the cloaca.
Explanation: Statements I, II and IV are correct because frogs are carnivores with a short alimentary canal, and the digestive tract continues from stomach to intestine, rectum and cloaca. Statement III is incorrect because the oesophagus opens into the stomach before the duodenum.
Question 48 of 101
📘 CLASS XI
Consider the following statements regarding digestion in the stomach of the frog:
I. Food is captured by a bilobed tongue. II. Chemical digestion begins in the stomach through the action of HCl and gastric juices. III. Gastric juices are secreted by the walls of the gall bladder. IV. Partially digested food exiting the stomach is called chyme.
Explanation: Statements I, II and IV are correct because frogs capture prey with a bilobed tongue, digestion begins in the stomach, and semi-digested food is called chyme. Statement III is incorrect because gastric juice is secreted by the stomach wall, not the gall bladder.
Question 49 of 101
📘 CLASS XI
Analyze the statements regarding the pancreatic and hepatic digestive contributions:
I. The pancreas is a digestive gland that produces pancreatic juice containing digestive enzymes. II. Bile is synthesized and secreted by the gall bladder. III. The duodenum receives bile and pancreatic juice through a common bile duct. IV. Bile emulsifies fat, while pancreatic enzymes digest carbohydrates and proteins.
Explanation: Statements I, III and IV are correct because the pancreas secretes digestive enzymes, bile and pancreatic juice enter the duodenum through a common duct, and bile emulsifies fats. Statement II is incorrect because bile is produced by the liver and stored in the gall bladder.
Question 50 of 101
📘 CLASS XI
Consider the following statements regarding intestinal absorption:
I. Final digestion of food takes place in the stomach. II. Final digestion of food takes place in the intestine. III. Digested food is absorbed by finger-like folds called villi and microvilli. IV. Villi and microvilli are present on the outer wall of the stomach to maximize absorption.
Explanation: Statement I is incorrect because final digestion occurs in the intestine. Statements II and III are correct because intestinal villi and microvilli absorb digested nutrients. Statement IV is incorrect because villi and microvilli are present on the inner wall of the intestine, not the stomach.
