Explain why sexual reproduction in angiosperms is said to take place through double fertilization and triple fusion. 

How are the male and female gametophytes of pteridophytes and gymnosperms different from each other?

A 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

45.

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