Question

Which one of the following statements is true about an organism and its classification?
(a)Blue-green alga is a kind of fungus
(b)Seahorses are closely related to dolphins.
(c)Maidenhair tree is a kind of angiosperm.
(d)Sealily is a kind of echinoderm

Answer 1

Hint: The organism belongs to Crinoidea. The adult of this organism is attached to the bottom of the sea with the help of a stalk.

Complete answer:
1. Bluegreen bacteria/Cyanobacteria are autotrophic bacteria (not fungus).
2. Seahorse is closely related to species of small marine fish and the genus hippocampus, whereas dolphins belong to the class of mammals.
3. Maidenhair tree or Ginkgo biloba is a living fossil belonging to division Ginkgophyta
4. Sealily belongs to the class of Echinoderm and consists of both endoskeleton and exoskeleton. Sea lily, a crinoid marine invertebrate animal (class Crinoidea, phylum Echinodermata) in which the adult is fixed to the sea bottom by a stalk. Thus the correct answer is Sea Lily is a kind of Echinoderm.

Additional information:
Classification is the arrangement of organisms based on similar and dissimilar characters. The most widely accepted form of classification was given by R.H. Whitteker during the year 1969. According to which organisms are divided into five different kingdoms. These are Monera (consist prokaryotes), Protista (consist all unicellular eukaryotes), Fungi (consist all saprophytic eukaryotes), Plantae (consist all autotrophic eukaryotes), Animalia (consist heterotrophic eukaryotes).
Further, the classification is divided into taxa like Phylum for animals and Division for plants, Class, Order, Family, Genus, and the smallest one species. Blue-green algae are the unicellular, autotrophic bacteria but initially kept under plants due to the presence of chlorophyll similarly fungi were also considered as plants due to the presence of cell wall.

So, the correct answer is ‘Sealily is a kind of Echinoderm’.

Note:
-Maidenhair or Ginkgo is a single plant left in its division and originates from China as the seeds are protected by flowers we can consider as gymnosperms morphologically.
-Solenodon is also a living fossil animal found in the Caribbean islands of Hispaniola and Cuba.