Problem 223 - Objective Biology for NEET

Question

Oviparous mammal is (a) Canis (dog) (b) Felis (cat) (c) Pteropus (flying fox (d) Ornithorhynchus (platypus)

Step-by-Step Solution

Answer

(d) Ornithorhynchus (platypus)

Step 1: Identify Oviparous Animals

First, identify which of the listed animals are known to lay eggs. This is where knowledge of animal biology will come into play.

Step 2: Identify the Oviparous Mammal

Next, since the exercise is asking specifically for an oviparous mammal, identify which of the egg-laying animals from Step 1 are mammals.

Step 3: Select the Correct Answer

Lastly, recognize that Ornithorhynchus, also known as the platypus, is the only egg-laying mammal in the provided list. Thus, the correct answer is (d) Ornithorhynchus (platypus).

Key Concepts

Ornithorhynchus

Ornithorhynchus, commonly known as the platypus, is a unique and fascinating creature. It's an unusual member of the animal kingdom primarily because it breaks the norms of typical mammalian characteristics. Found in eastern Australia, including Tasmania, the platypus is one of only five species of monotremes. These are egg-laying mammals.

The platypus has distinctive features, such as a duck-bill, webbed feet, and a beaver-like tail. Despite being a mammal, it resembles a blend of different animal traits. This distinct combination has often surprised and intrigued scientists. It is also important to note that the male platypus has venomous spurs on its hind limbs, a trait not common among mammals.

Understanding the platypus helps us appreciate the diversity and adaptability of mammals in different environments. Its existence challenges the conventional perception of mammals, highlighting the complexity and variability of life forms on Earth.

Egg-laying animals

Egg-laying animals, also scientifically termed as 'oviparous', are species that reproduce by laying eggs. This mode of reproduction spans across various animal groups, including birds, reptiles, amphibians, certain fish, and some invertebrates. Unlike mammals that typically give live birth, oviparous animals nurture their young inside eggs.

Birds are perhaps the most well-known group of egg layers due to their elaborate nesting behaviors. Reptiles, like turtles and lizards, also follow this reproductive strategy, often burying their eggs for protection. Among mammals, monotremes, such as the platypus and echidna, are unique for being oviparous. They lay eggs but share other mammalian traits like producing milk.

Egg-laying can offer several advantages, such as increased mobility and less energy expenditure than carrying offspring internally. It also allows for a greater number of offspring to be produced at once, increasing the chances of survival for the species.

Animal biology

Animal biology is an extensive field that covers the study of various life processes and structures of animals. It includes the physiological mechanisms, behavior, and evolutionary history that define them.

The study of animal biology allows for an understanding of diverse biological systems across different habitats. It examines how animals interact with their environment and adapt to changes. Such knowledge is crucial for fields like ecology, conservation, and medical research.

Key areas of animal biology include anatomy, which deals with the structural aspect; physiology, focusing on functional processes; and ecology, interacting with environmental factors. With the study of animal biology, scientists can also explore genetic makeup and biodiversity, forming strategies to protect endangered species and maintain ecological balance.

Mammalian reproduction

Mammalian reproduction generally involves live birth and internal fertilization, but there are exceptions like monotremes. This group, which includes species such as the platypus and echidna, are notable for laying eggs rather than birthing live young.

In typical mammalian reproduction, the fetus develops inside the mother's body through a complex process involving placental nourishment and growth until birth. This process provides protection and a stable environment crucial for the developing embryo.

Monotremes, though, have a different reproductive path. After laying eggs, the mother incubates them outside her body. Once hatched, the young feeds on milk, a characteristic shared by all mammals. Despite their different modes of reproduction, all mammals share common traits such as warm-bloodedness and the presence of mammary glands, which play a significant role in nurturing the young.