Tag: classification of pteridophytes

Questions Related to classification of pteridophytes

Heteromorphic alternation of generations occurs in

  1. Dictyota

  2. Selaginella

  3. Rhizopus

  4. Spirogyra


Correct Option: B

In Selaginella, the male gametes are

  1. Uniflagellate

  2. Biflagellate

  3. Non-flagellate

  4. Multiflagellate


Correct Option: B

A pteridophyte having pyrenoid in its chloroplasts is

  1. Pteridium

  2. Selaginella

  3. Equisetum

  4. Marsilea


Correct Option: B

Selaginella sperms swim towards archegonia. The phenomenon is

  1. Chemotaxis

  2. Chemotropism

  3. Chemonasty

  4. Thigmonasty


Correct Option: A
Explanation:

Chemotaxis is the movement shown by organism in the direction of the external chemical stimuli. In Selaginella, sperm sense the chemoattractant and orient its swimming towards the archegnonia. Chemotropism is the growth movement shown by organism in the direction of the external chemical stimuli. Chemonasty is the nastic movement shown by organism in response to the external chemical stimuli. Spermatozoa can sense this chemoattractant and orient their swimming direction up the concentration gradient towards the egg cell located in the venter of archegonia

So, the correct answer is 'Chemotaxis'

Which of the following are heterosporous pteridophytes?
I. Lycopodium   II. Selaginella   III. Equisetum   IV. Salvinia

  1. I and II

  2. II and III

  3. III and IV

  4. II and IV

  5. I and IV


Correct Option: D

Integument like covering of megasporangium occurs in Selaginella

  1. S. apus

  2. S. rupestris

  3. S. sulcata

  4. S. yemensis


Correct Option: A
Explanation:
A) S. apus
The sporophyte is herbaceous. The shoot is dorsiventral and radial and creeping or erect. An ovule consists of a megasporangium, is surrounded by a single covering or integument, and eventually will become a seed.

Megaspores are retained inside megasporogonium for germination in species of Selaginella

  1. S.bryopteris and S.lepidophylla

  2. S.chrysocaulos and S.subdiaphana

  3. S.selaginoides and S.kraussiana

  4. S.apus and S.rupestris


Correct Option: A

Ptyxis is

  1. Arrangement of leaves on the stem

  2. Arrangement of leaves in the bud

  3. Folding of lamina in bud

  4. Both B and C


Correct Option: C
Explanation:

The folding of lamina in bud condition is called as ptyxis. Arrangement of leaves on the stem branches is called as phyllotaxy. Vernation is the phenomenon of arrangement of leaves in the bud. 

Thus, the correct answer is 'Folding of lamina in bud.'

Tracheophyta characterised by habitual heterophylly, absence of companion cells and presence of vessels in xylem is

  1. Pteris

  2. Drimys

  3. Selaginella

  4. Gnetum


Correct Option: C

Which one does not occur in Selaginella?

  1. Heterospory

  2. Heterophylly

  3. Homospory

  4. Ligulate leaves


Correct Option: C