UPSC Prelims 2023 Question:

Consider the following statements:

• Statement-1: Marsupials are not naturally found in India.
• Statement-II: Marsupials can thrive only in montane grasslands with no predators.
  
  

Which one of the following is correct in respect of the above statements?

Learn more about Marsupials- The pouched Mammals.

Explanation:

• Marsupials (Metatheria) are pouched mammals, that is mammals in which the females bear their young alive but in an almost foetal state and, in most species, carry them within an external pocket or pouch formed by a flap of dermal tissue on the abdomen. The most familiar marsupials are the kangaroos. The Marsupials are native to Australia. They are not naturally found in India. So, statement 1 is correct.
• Marsupials are mostly found in arid and semi-arid regions and not only in montane grasslands with no predators. So, statement 2 is not correct.
  
  

Characteristics of Marsupials

• Marsupials are viviparous.
• Marsupials lack placenta. 
• They have external body pouches.
• The external body pouch is used by the mother to keep their babies for providing parental care. 
• The mother marsupial possesses mammary glands to feed their infant babies for several months. 
• Marsupials are mammals, but they possess some characteristics which make them unique in comparison to other mammals like pouches which are not found in other mammals.
• Just like other vertebrate mammals, marsupials do not have complex neural structures called corpus callosum in their brain. The corpus callosum has a simple network of nerve fibres that connect the two sides. As compared to placental mammals, the size of the marsupial brain is also small and the versatility to perform a particular function is less than placental mammals, indicating that they are less intelligent than placental mammals.
• Marsupials reside in a wide range of habitats. They can be found in dry scrublands, temperate deciduous forests and tropical rainforests.
• Marsupials are found in the different regions of North, South and Central America, Australia, New Zealand and Tasmania.
• Most of the marsupials reside in warmer climates. They have low body temperature and have a slow metabolic rate compared to mammals possessing placenta. The internal body temperature of marsupials lies in the range of 5.4-5.6 degrees Fahrenheit, which is 3 degrees lower than the temperature of placental mammals.
  
  

Therefore, option (3) is the correct answer.