Long Answer TypeExplain why sexual reproduction in angiosperms is said to take place through double fertilization and triple fusion.
In angiosperms, one male gamete fuses with the female gamete. In addition to this, another male gamete fuses with the secondary nucleus. Fusion between male and female gametes result in the formation of zygote. While the fusion of the male gamete and the secondary nucleus forms the primary endosperm nucleus or (PEN).
Since two instances of fusion of nuclei take place hence the phenomenon is known as Double fertilisation.
The phenomenon is called triple fusion as the male gamete fuses with the secondary nucleus having two polar nuclei and results in the formation of endosperm which has 3n chromosome.
How are the male and female gametophytes of pteridophytes and gymnosperms different from each other?
Multiple Choice QuestionsA Prothallus is
A structure in pteridophytes formed before the thallus develops
A sporophytic free living structure formed in pteridophytes
A gametophyte free living structure formed in pteridophy
A primitive structure formed after fertilization in pteridophytes
Protonema is
Haploid and is found in mosses
Diploid and is found in liverworts
Diploid and is found in pteridophytes
Haploid and is found in pteridophytes
The giant Redwood tree (Sequoia sempervirens) is a/an
Angiosperm
Free fern
Pteridophyte
Gymnosperm
Which one of the following statements is wrong?
Golden algae are also called desmids
Eubacteria are also called false bacteria
Phycomycetes are also called algal fungi
Phycomycetes are also called algal fungi
Select the correct statement
Salvinia, Gingko and Pinus all are gymnosperm
Sequoia is oneis one ot the talles trees
The leaves of gymnosperm are not well adapted to extremes of climate
The leaves of gymnosperm are not well adapted to extremes of climate
Isogamous condition with non-flagellated gametes is found in
Chlamydomonas
Spirogyra
Volvox
Volvox
Which of the following are likely to be present in deep sea water?
Archaebacteria
Eubacteria
Blue-green algae
Blue-green algae
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