Which pteridophyte has the maximum chromosome number?
A. Ophioglossum reticulatum
B. Azolla pinnata
C. Lycopodium cernuum
D. Selaginella apus
VerifiedHint: The Pteridophytes include horsetails and ferns. Pteridophytes are used for medicinal purposes and as soil-binders. They are also frequently grown as ornamentals. Evolutionarily, they are the first terrestrial plants to possess vascular tissues - xylem and phloem.
Complete answer:
Different species of pteridophytes have different numbers of chromosomes. One species of pteridophytes contains more chromosomes than humans .
Ophioglossum reticulatum: It contains chromosomes more than that present in humans. It has 1260 chromosomes that is 630 pairs of chromosomes that is the highest of all.
Azolla pinnata: It is a type of fern. It has 44 pairs of chromosomes which is less than the above option . Hence this option is not correct.
Lycopodium cernuum: It mostly contains 114 chromosomes but once from South Africa 340 numbers of chromosomes were reported. But this number is also less than that present in Ophioglossum. Hence this option can’t be correct.
Selaginella apus: This species has the lowest number of chromosomes among four . It contains only 18 pairs of chromosomes . Hence this option can not be correct.
Our required answer is a. Ophioglossum reticulatum.
Note: Brood Parasitism: It is a kind of parasitism which is found in birds where a parasitic bird lays its eggs in the nest of its host (other birds) and lets the host incubate them. For example, a cuckoo (parasite) lays its eggs in a crow's (host) nest.
