Cycas is a living fossil as it has
A. Ciliated sperms
B. Structure like that of tree fern
C. Restricted occurrence in certain areas
D. Been found in fossil state also
Answer
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Hint: Fossils are the non-degraded remains or signs of ancient living organisms discovered within rock life preserved in the Earth's crust. The word "fossil" comes from the Latin word "fossus," which means "dug up."
The similarities and differences between living species and extinct specimens are referred to as "living fossils." Charles Darwin, an English biologist, coined the term "living fossil."
Complete answer:
Option A: The fertilisation of Cycas takes place in this fashion, with motile ciliated sperms, a phenomenon known as zoidogamy. In Cycas, zoidogamy is accompanied with the production of pollen tubes, a phenomenon known as siphonogamy. The pollen tube serves as a carrier for sperm.
So option A is not correct.
Option B: It gets its name from the fact that it shares many characteristics with extinct pteridosperms and cycads.
So option B is not correct.
Option C: A living fossil is an organism whose relatives can only be found in the fossil condition and which has a limited distribution and is typically on the verge of extinction.
So option C is correct.
Option D: A living fossil is an organism whose relatives can only be found in the fossil state, has a small range, and is usually on the approach of extinction.
So option D is not correct.
So option C is the correct answer.
Note:
The Psilotum species is a living fossil from the pre-dinosaur era. It grows vertically with leafless whisk-like branches and can be found in tropical climates all over the world. It is a descendant of the Rhyniophytes, the first vascular land plants that originated on the planet approximately million years ago. In contrast to more sophisticated flowering plants, it has flagellated sperm and lacks roots and leaves, highlighting its basic character. Another feature that explains its early evolutionary origin is the lack of seeds in the reproductive cycle.
The similarities and differences between living species and extinct specimens are referred to as "living fossils." Charles Darwin, an English biologist, coined the term "living fossil."
Complete answer:
Option A: The fertilisation of Cycas takes place in this fashion, with motile ciliated sperms, a phenomenon known as zoidogamy. In Cycas, zoidogamy is accompanied with the production of pollen tubes, a phenomenon known as siphonogamy. The pollen tube serves as a carrier for sperm.
So option A is not correct.
Option B: It gets its name from the fact that it shares many characteristics with extinct pteridosperms and cycads.
So option B is not correct.
Option C: A living fossil is an organism whose relatives can only be found in the fossil condition and which has a limited distribution and is typically on the verge of extinction.
So option C is correct.
Option D: A living fossil is an organism whose relatives can only be found in the fossil state, has a small range, and is usually on the approach of extinction.
So option D is not correct.
So option C is the correct answer.
Note:
The Psilotum species is a living fossil from the pre-dinosaur era. It grows vertically with leafless whisk-like branches and can be found in tropical climates all over the world. It is a descendant of the Rhyniophytes, the first vascular land plants that originated on the planet approximately million years ago. In contrast to more sophisticated flowering plants, it has flagellated sperm and lacks roots and leaves, highlighting its basic character. Another feature that explains its early evolutionary origin is the lack of seeds in the reproductive cycle.
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