Tag: biology

Questions Related to biology

Spindle shaped male gametes are found in

classification of pteridophytes kingdom plantae plant kingdom biology

  1. Lycopodium

  2. Pteris

  3. Pteridium

  4. Selaginella

Show answer
Correct Option: D
Explanation:

Selaginella is a pteridophyte also known as spike moss or little club moss. It is a tropical plant. It has world wide distribution. It grows in damp forests. Some species occur in temperate regions. They grow in moist shady places. In Selaginella male gametes are spindle shaped and biflagellate. Hence option D is correct.

Selaginella has a tendency to form seed, called seed habit, because it follows 

classification of pteridophytes kingdom plantae plant kingdom biology

  1. Retention of megaspore permanently inside the megasporangium

  2. Heterospory

  3. Both above characters

  4. None of the above

Show answer
Correct Option: A
Explanation:

Selaginella is a genus of primitive vascular plants in the family Selaginellaceae. Selaginella has a tendency to form seed because the retention and germination of single megaspore within megasporangium to form a female gametophyte led to the phenomenon of seed habit, a characteristic feature of spermatophytes.

So, the correct answer is 'Retention of megaspore permanently inside the megasporangium'.

The evolutionary advanced features of Selaginella are :
(a) Heterospory
(b) Endosporic development of gametophyte.
(c) Reduced gametophyte
(d) Localization of sporangium bearing appendages in strobili.
(e) Unisexual gametophytes
(f) fertilization with the help of water.

classification of pteridophytes kingdom plantae plant kingdom biology

  1. All are correct

  2. All expect (f) are correct

  3. All expect (e) and (f) are correct

  4. All expect (c) is correct.

Show answer
Correct Option: A

Rudimentary seed habit is found in

classification of pteridophytes kingdom plantae plant kingdom biology

  1. Selaginella

  2. Lycopodium

  3. Equisetum

  4. Adiantum

Show answer
Correct Option: A
Explanation:

Rudimentary seed habit means plants are reproducing sexually by seed but it is not fully developed. For e.g. in Selaginella female gametophytes are retained on the parent sporophytes for different periods. Within the female gametophytes, the development of the zygote into young embryos takes place. This event is a very important step in evolution as a precursor to seed habit. 

So the correct option is 'Selaginella'.

Most ancient vascular plants belong to which class :

classification of pteridophytes kingdom plantae plant kingdom biology

  1. Sphenopsida

  2. Lycopsida

  3. Pteropsida

  4. Psilopsida

Show answer
Correct Option: A

Heterospory is found in

classification of pteridophytes kingdom plantae plant kingdom biology

  1. Funaria

  2. Dryopteris

  3. Marchantia

  4. Selaginella

Show answer
Correct Option: D

Arrangement of leaves in the bud condition is called _________.

classification of pteridophytes kingdom plantae plant kingdom biology

  1. Phyllotaxy

  2. Insertion

  3. Ptyxis

  4. Vernation

Show answer
Correct Option: D
Explanation:
Arrangement of leaves on the stem branches is called as phyllotaxy. 
Insertion is the angle and orientation of the leaves with respect to the axis of the stem. 
The folding of lamina in bud condition is called as ptyxis. 
Vernation is the phenomenon of arrangement of leaves in the bud condition.
Thus, the correct answer is 'Vernation.'

Which one of the following is not a correct statement ?

classification of pteridophytes kingdom plantae plant kingdom biology

  1. Herbarium houses dried, pressed and preserved plant specimens

  2. Botanical gardens have collection of living plants for reference

  3. A museum has collection of photographs of plants and animals

  4. Key is a taxonomic aid for identification of specimens

Show answer
Correct Option: C
Explanation:
Museum is the collection of dead and preserved specimen of animals generally.
So, the correct answer is 'A museum has collection of photographs of plants and animals'

Heterosporous pteridophytes (e.g., Selaginella) always produce ................ gametophytes

classification of pteridophytes kingdom plantae plant kingdom biology

  1. Monoecious

  2. Dioecious

  3. Homothallic

  4. None of the above

Show answer
Correct Option: B
Explanation:

Heterosporous pteridophytes (e.g., Selaginella) always produce dioecious gametophytes. A heterosporous life history occurs in some pteridophytes and in all seed plants. It is characterized by morphologically dissimilar spores produced from two types of sporangia: microspores, or male spores, and megaspores (macrospores), or female spores. In pteridophytes, megaspores are typically larger than microspores, but the opposite is true in most seed plants.

The cell of Dryopteris, prothallus contain nucleus with

classification of pteridophytes kingdom plantae plant kingdom biology

  1. 4 n chromosomes

  2. 3 n chromosomes

  3. 2 n chromosomes

  4. n chromosomes

Show answer
Correct Option: D
Explanation:

Prothallus is the self supporting haploid plant of the gametophytic generation and is concerned with sexual reproduction. Prothallus is generally monoecious and bears sex organs on the ventral side.