This set of Class 11 Biology Chapter 7 Multiple Choice Questions & Answers (MCQs) focuses on “Animals – Organs and Organ System – 3”.
1. In which of the following classes does the frog belong?
a) Class Aves
b) Class Amphibia
c) Class Reptilia
d) Class Mammalia
View Answer
Explanation: Frogs can live both on land and in freshwater and belong to class Amphibia of phylum Chordata. The most common species of frog found in India is Rana tigrina.
2. Why are frogs not seen during peak summer and winter?
a) They die
b) They play hide and seek
c) They hide to protect themselves
d) They shift their places
View Answer
Explanation: The frogs are not seen during peak summer and winter because during this period they take shelter in deep burrows to protect them from extreme heat and cold. This is called as summer sleep (Aestivation) and winter sleep (Hibernation) respectively.
3. In how many parts is the body of the frog divisible?
a) One
b) Two
c) Three
d) Four
View Answer
Explanation: The body of a frog is divisible into 2 parts which are head and trunk. A neck and a tail are absent. Above the mouth, a pair of nostrils is present.
4. Which of the following structures protect the eyes of frog in water?
a) Tympanum
b) Eyelashes
c) Eyelid
d) Nictitating membrane
View Answer
Explanation: Eyes of frog are bulged out and are covered by a nictitating membrane that protects them while in water. On either side of the eyes, a membranous tympanum receives sound signals.
5. Frogs exhibit sexual dimorphism.
a) True
b) False
View Answer
Explanation: Frogs exhibit sexual dimorphism. Male frogs can be distinguished by the presence of sound-producing vocal sacs and also a copulatory pad on the first digit of the forelimbs which are absent in female frogs.
6. Why is the alimentary canal of frogs short?
a) They are carnivores
b) They are omnivores
c) They are herbivores
d) They do not eat food
View Answer
Explanation: The alimentary canal of frogs is short because they are carnivores and hence the length of the intestine is reduced. The digestive system consists of the alimentary canal and digestive glands.
7. By the use of which of the following structures, frogs capture food?
a) Mouth
b) Bilobed tongue
c) Trilobed tongue
d) Hind limb
View Answer
Explanation: Food is captured by the bilobed tongue of the frog. Digestion of food takes place by the action of HCl and gastric juices secreted from the walls of the stomach.
8. By which of the following do frogs do not respire?
a) Skin
b) Lungs
c) Buccal cavity
d) Ear
View Answer
Explanation: Frogs respire on land and in water by two different methods. In water, skin acts as an aquatic respiratory organ. On land, the buccal cavity, skin and lungs act as the respiratory organs.
9. How many chambers are present in the heart of the frog?
a) Two
b) Three
c) Four
d) Five
View Answer
Explanation: The heart of a frog has three chambers, two atria and one ventricle and is covered by a membrane called the pericardium. A triangular structure called as sinus venosus joins the right atrium.
10. Hepatic portal system and Renal portal system are present in the frog.
a) True
b) False
View Answer
Explanation: Special venous connection between liver and intestine as well as the kidney and lower parts of the body are present in the frogs. The former is called a hepatic portal system and the latter is called the renal portal system.
11. Which of the following is not a part of the excretory system of frogs?
a) Kidneys
b) Ureters
c) Vasa efferentia
d) Cloaca
View Answer
Explanation: The elimination of nitrogenous wastes is carried out by a well-developed excretory system. The excretory system consists of a pair of kidneys, ureters, cloaca and urinary bladder.
12. Where does the urinogenital duct open in the case of frogs?
a) Kidneys
b) Cloaca
c) Urinary bladder
d) Testis
View Answer
Explanation: Two ureters emerge from the kidneys in male frogs. The ureters act as a urinogenital duct which opens into the cloaca. In females the ureters and oviduct separately in the cloaca.
13. In which form does the frog excrete out the nitrogenous waste?
a) Ammonia
b) Nitrogen
c) Urea
d) Uric acid
View Answer
Explanation: The frog excretes nitrogenous wastes in the form of urea and thus is a ureotelic organism. Excretory wastes are carried by blood into the kidney where it is separated and excreted.
14. Which of the following is an organ of hearing as well as balancing?
a) Eyes
b) Ear
c) Tongue
d) Skin
View Answer
Explanation: The ear is an organ of hearing as well as balancing. The external ear is absent in frogs and the only tympanum can be seen externally.
15. Which of the following does not pass through cloaca?
a) Faecal matter
b) Tears
c) Urine
d) Sperms
View Answer
Explanation: The cloaca is a small, median chamber that is used to pass faecal matter, urine and sperms to the exterior in male frogs. In female frogs, a pair of oviducts arising from the ovaries open into the cloaca separately.
Sanfoundry Global Education & Learning Series – Biology – Class 11.
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