Which one of the following is heterosporous?
Dryopteris
Salvinia
Adiantum
Adiantum
B.
Salvinia
Heterospory is the production of spores of two different sizes and two different developmental patterns. Small spores are called microspores and larger as megaspore. Microspores germinate to produce the male gametophyte or microgametophyte that bear male sex organs while megaspores germinate to form female gametophyte or megagametophytes that bear archegonia or female sex organs. It is most important evolutionary development in the vascular plants because it has ultimately lead to seed development eg, Selaginella, Marselia Salvinia, Azolla, isoetes.
Dryopteris is homosporous a 32-64 haploid spores are produced in each sporangium.
Adiantum is also homosporous. The spores are the pioneer structures of the gametophytic generation.
Which one of the following is considered important in the development of seed habit?
Dependent sporophyte
Heterospory
Haplontic life cycle
Haplontic life cycle
Which one of the following is a vascular cryptogam?
Equisetum
Ginkgo
Marchantia
Marchantia
The scutellum observed in a grain of Wheat or maize is comparable to which part of the seed in other monocotyledons?
Cotyledon
Endosperm
Aleurone layer
Aleurone layer
Examine the figure A, B, C, and D. In which one of the four options, all the items A, B, C and D are correct.
|
A |
B |
C |
D |
|
Chara |
Marchantia |
Fucus |
Pinus |
|
A |
B |
C |
D |
|
Equisetum |
Ginkgo |
Selaginella |
Lycopodium |
|
A |
B |
C |
D |
|
Selaginella |
Equisetum |
Salvinia |
Ginkgo |
|
A |
B |
C |
D |
|
Selaginella |
Equisetum |
Salvinia |
Ginkgo |
The correct sequence of plants in a hydrosere is
Oak → Lantana → scirpus→Pistia→Hydrilla→Volvox
Volvox → Hydrilla → Pistia → Scirpus → Lantana → Oak
Pista → Volvox → Scirpus → Hydrilla → Oak → Lantana
Pista → Volvox → Scirpus → Hydrilla → Oak → Lantana
