Anatomy of the Frog Practice Questions
19 free Anatomy of the Frog practice questions for the NCERT Biology. Tap an option to answer — you get instant feedback, the correct answer, and a detailed explanation for every question.
The digestive system of a frog consists of an alimentary canal and digestive glands. The alimentary canal is short because:
- A Frogs are carnivores
- B Frogs are herbivores
- C Frogs are omnivores
- D Frogs undergo metamorphosis
Correct answer: Frogs are carnivores
In frogs, the length of the intestine is reduced because they are carnivorous. Since meat is easier to digest than cellulose-rich plant matter, a long alimentary canal is not required.
In the digestive system of a frog, the food is captured by the:
- A Forked tongue
- B Teeth present on the upper jaw
- C Trifid tongue
- D Sticky pharynx
Correct answer: Forked tongue
Frogs possess a characteristic forked (bifid) tongue that is attached at the front of the mouth. This allows the tongue to be flicked out rapidly to capture prey.
The stomach of a frog secretes which of the following to initiate digestion?
- A Gastric juice and HCl
- B Bile and pancreatic juice
- C Intestinal juice only
- D Salivary amylase
Correct answer: Gastric juice and HCl
The walls of the stomach secrete gastric juice and HCl, which begin the chemical breakdown of food. The partially digested food resulting from this process is called chyme.
In frogs, the final digestion and absorption of nutrients take place in the:
- A Stomach
- B Duodenum
- C Colon
- D Ileum
Correct answer: Ileum
While digestion starts in the stomach and continues in the duodenum, the final digestion and absorption occur in the ileum. The inner wall of the ileum has finger-like folds called villi and microvilli to increase the surface area for absorption.
Which duct carries both bile and pancreatic juice into the duodenum of a frog?
- A Cystic duct
- B Hepatic duct
- C Submandibular salivary duct
- D Common bile-pancreatic duct
Correct answer: Common bile-pancreatic duct
The liver produces bile, which is stored in the gall bladder, and the pancreas produces pancreatic juice. Both these secretions are delivered to the duodenum through a single common bile-pancreatic duct.
The undigested solid waste in a frog moves into the rectum and passes out through the:
- A Cloaca
- B Anus
- C Urethra
- D Ureter
Correct answer: Cloaca
The cloaca is a common chamber in frogs used for discharging faeces, urine, and gametes. It serves as the terminal opening for the digestive, excretory, and reproductive tracts.
During pulmonary respiration on land, air enters the lungs through the nostrils and the:
- A Pharyngeal cavity
- B Buccal cavity
- C Esophagus
- D Trachea
Correct answer: Buccal cavity
On land, the buccal cavity acts as a force pump. Air is drawn into the buccal cavity through the nostrils and is then forced into the lungs for gaseous exchange.
In frogs, the lungs are described as:
- A A pair of elongated, black-colored sacs
- B A pair of elongated, pink-colored sac-like structures
- C A single large lung located dorsally within the thoracic cavity
- D Four-chambered respiratory organs
Correct answer: A pair of elongated, pink-colored sac-like structures
Frogs have a pair of elongated, pink-colored, sac-like lungs located in the upper part of the trunk region (thorax). However, pulmonary respiration in frogs is generally less efficient compared to cutaneous respiration.
During aestivation (summer sleep) and hibernation (winter sleep), gaseous exchange in frogs takes place exclusively through the:
- A Lungs
- B Buccal cavity
- C Moist skin
- D Gills
Correct answer: Moist skin
During periods of dormancy like aestivation and hibernation, the metabolic rate is very low. The skin alone provides sufficient surface area for the necessary gaseous exchange with the environment.
The vascular system of a frog is of the 'closed type' and includes which of the following?
- A Heart, blood vessels, and blood
- B Heart and hemolymph fluid only
- C Open sinuses and heart
- D Tracheal tubes connected to the heart
Correct answer: Heart, blood vessels, and blood
Frogs possess a closed circulatory system where blood is confined to a network of vessels (arteries, veins, and capillaries) and is pumped by a muscular heart.
How many chambers are present in the heart of a frog?
- A 2
- B 3
- C 4
- D 1
Correct answer: 3
The frog heart is three-chambered, consisting of two upper atria (left and right) and a single lower ventricle. The heart is covered by a protective membrane called the pericardium.
The triangular structure that joins the right atrium and receives blood from the vena cava is the:
- A Conus arteriosus
- B Sinus venosus
- C Truncus arteriosus
- D Mitral valve
Correct answer: Sinus venosus
The sinus venosus is a large triangular chamber that receives deoxygenated blood from the major veins (vena cava) and delivers it into the right atrium.
The ventricle of the frog heart opens into a sac-like structure on the ventral side called the:
- A Sinus venosus
- B Conus arteriosus
- C Atrioventricular valve
- D Pulmonary vein
Correct answer: Conus arteriosus
The conus arteriosus is a muscular tube-like structure that arises from the ventricle. It helps in distributing blood from the single ventricle into the arterial system.
Which of the following describes the 'Renal Portal System' in frogs?
- A Venous connection between the liver and intestine
- B Arterial connection between the heart and kidneys
- C Lymphatic connection between the heart and kidneys
- D Venous link between the lower body and the kidneys
Correct answer: Venous link between the lower body and the kidneys
The renal portal system is a characteristic feature of frogs where blood from the posterior parts of the body is collected and filtered through the kidneys before returning to the heart.
The blood of a frog consists of plasma and cells. Which of the following cells contain the red pigment hemoglobin?
- A Leucocytes
- B Thrombocytes
- C Platelets
- D Erythrocytes
Correct answer: Erythrocytes
Erythrocytes (RBCs) in frogs are nucleated and contain hemoglobin for oxygen transport. Unlike mammalian RBCs, which are enucleated, frog RBCs retain their nucleus.
Which component of the circulatory system in frogs lacks certain proteins and RBCs?
- A Plasma
- B Hemolymph
- C Serum
- D Lymph
Correct answer: Lymph
Lymph is a fluid that circulates in the lymphatic system. It is similar to blood but lacks red blood cells and some large proteins, playing a key role in fluid balance and immunity.
Special venous connection between the liver and intestine in frogs is called the:
- A Renal portal system
- B Pulmonary system
- C Coronary circulatory system
- D Hepatic portal system
Correct answer: Hepatic portal system
The hepatic portal system allows nutrient-rich blood from the digestive tract to pass through the liver. This allows for the processing and storage of nutrients before the blood reaches the rest of the body.
The primary function of the lymphatic system in frogs is to:
- A Pump oxygenated blood to the lungs
- B Absorb proteins from the stomach
- C Return fluid and proteins to blood
- D Produce and store red blood cells
Correct answer: Return fluid and proteins to blood
The lymphatic system, consisting of lymph, lymph channels, and lymph nodes, acts as a secondary circulatory system. It recovers fluid that leaks out of capillaries and returns it to the main venous system.
Which of the following statements about frog blood is FALSE?
- A RBCs are nucleated
- B Blood transports nutrients, gases, and water to tissues
- C Hemoglobin is the respiratory pigment
- D The heart has four distinct chambers
Correct answer: The heart has four distinct chambers
A frog's heart has only three chambers: two atria and one ventricle. The statement about four chambers is false, as that is a characteristic of birds and mammals.