1
Question
For which of the following group of organisms do biologists have no estimate of the available number of different species on earth?
For which of the following group of organisms do biologists have no estimate of the available number of different species on earth?
Open in App
Solution
The correct option is C Monerans
The IUCN (2004) stated that more than 1.5 million different species of plants and animals have been identified and described by biologists so far.
Although, according to the estimates given by Robert May, only 22% of the total number of species have been discovered so far and the global species diversity is likely to be around 7 million.
But these numbers do not include the number of species belonging to Kingdom Monera (prokaryotes).
The reasons being:
- The conventional taxonomic methods are unable to identify and classify prokaryotic species
- Many prokaryotic organisms are impossible to culture in vitro and hence cannot be studied properly
Thus, biologists are not very certain about the number of existing prokaryotic species. However if we consider biochemical or molecular characteristics as criteria for distinguishing and identifying the prokaryotic species, the chances are that the numbers might run into millions.
According to the existing inventory on the identified species, more than 70% of all the recorded species are animals and about 22% of the recorded species belong to plants and fungi.
More than 70% of the animal species belong to the class Insecta which makes the insects the most species-rich taxonomic group.
Amongst plants, the highest species diversity is shown by angiosperms (flowering plants), followed by algae, mosses (bryophytes) and ferns (pteridophytes).
Fungi are approximately as diverse as the angiosperms and the total number of fungi species in the world is more than the sum total of the number of species belonging to fishes, reptiles, amphibians and mammals.
The IUCN (2004) stated that more than 1.5 million different species of plants and animals have been identified and described by biologists so far.
Although, according to the estimates given by Robert May, only 22% of the total number of species have been discovered so far and the global species diversity is likely to be around 7 million.
But these numbers do not include the number of species belonging to Kingdom Monera (prokaryotes).
The reasons being:
- The conventional taxonomic methods are unable to identify and classify prokaryotic species
- Many prokaryotic organisms are impossible to culture in vitro and hence cannot be studied properly
According to the existing inventory on the identified species, more than 70% of all the recorded species are animals and about 22% of the recorded species belong to plants and fungi.
More than 70% of the animal species belong to the class Insecta which makes the insects the most species-rich taxonomic group.
Amongst plants, the highest species diversity is shown by angiosperms (flowering plants), followed by algae, mosses (bryophytes) and ferns (pteridophytes).
Fungi are approximately as diverse as the angiosperms and the total number of fungi species in the world is more than the sum total of the number of species belonging to fishes, reptiles, amphibians and mammals.
Suggest Corrections
1
Similar questions
View More
Join BYJU'S Learning Program
Explore more
Join BYJU'S Learning Program
