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monotreme mammal

Primary Information
Secondary Information

Definition

Monotremes are mammals that lay eggs. They are the only mammals that do this. Monotremes are found in Australia and New Guinea. There are three species of monotremes: the platypus, the echidna, and the long-beaked echidna.

Monotremes are unique mammals in a number of ways. They are the only mammals that lay eggs. They also have a cloaca, which is a single opening for the digestive, excretory, and reproductive systems. Monotremes have a single opening for the digestive, excretory, and reproductive systems.

Monotremes are also unusual in that they have a mix of features that are found in both mammals and reptiles. For example, monotremes have fur, like mammals, but they also have a cloaca, like reptiles. Monotremes also lay eggs, like reptiles, but they also nurse their young, like mammals.

The defining characteristic of monotremes is that they lay eggs. This is in contrast to all other mammals, which give birth to live young. Monotremes are thought to be the most primitive group of mammals, and they are a valuable link to the evolution of mammals.

How can the word be used?

There are only five species of monotreme mammals in the world: the platypus and four species of echidna.

monotreme mammal

Different forms of the word

There are no different forms of the word "monotreme mammal.".

Etymology

The word "monotreme" comes from the Greek words "monos" (meaning "one") and "treme" (meaning "hole"). This is because monotremes have a single opening in their bodies that serves as both a cloaca (a chamber where the digestive, urinary, and reproductive systems meet) and a vagina.

The word "monotreme" was first used in English in the 18th century by the English naturalist George Shaw. Shaw used the word to describe the platypus, which was a new and strange animal that he had recently discovered in Australia.

Question

What is a monotreme mammal?

AQA Science Exam Question and Answer

Question:

What is a monotreme mammal, and how does it differ from other types of mammals? Provide an example of a monotreme mammal and describe its unique reproductive and physiological characteristics.

Answer:

A monotreme mammal is a unique subgroup of mammals characterised by their distinct reproductive and physiological features that set them apart from other mammals. Unlike placental mammals and marsupials, monotremes lay eggs as opposed to giving birth to live young.

One example of a monotreme mammal is the platypus (Ornithorhynchus anatinus), native to Australia. The platypus is renowned for its fascinating combination of features. It has a duckbill, webbed feet, and a flat tail, making it an excellent swimmer. However, its most remarkable attribute is its reproductive system. Female platypuses lay eggs, which are incubated outside the body. This method is quite distinct from both placental mammals that give birth and marsupials that carry underdeveloped young in pouches.

Furthermore, male platypuses possess venomous spurs on their hind limbs, a feature not found in other mammals. These spurs are used during territorial disputes and competition for mates. The platypus's ability to both lay eggs and produce venom illustrates the unique evolutionary adaptations of monotreme mammals.