Amphibian of land plants, Bryophytes, Multiple Choice questions: NEET

 


🌑Ovrerview-
Bryophytes are  in the next hierarchy to Algae. Their bodies are more differentiated and developed  than Algae. They are also thallus-like but their Thallus is prostrate and erect.  They are nonvascular embryophytes including  mosses, liverworts and hornworts. 

Bryophytes are small plants and  they grow in moist, shady places. They have small height like shrubs  due to absence of roots, vascular tissues, mechanical tissues and cuticles.

They are terrestrial but require water for fertilization to  complete their life cycle. Hence, they are called “Amphibians of plant kingdom”.

The study of bryophytes is called bryology. Hedwig is called ‘Father of Bryology’. Shiv Ram Kashyap is the ‘Father of Indian Bryology’
The fossil record indicates that bryophytes evolved on earth about  430 million years ago during the Silurian period of Paleozoic era


🌑General  features of Bryophytes:

🔴OccurenceBryophytes grow in humid ,damp and shady places and hilly areas.

🔴Gametophyte stage -

👉The dominant and main plant body is gametophyte which is haploid .

👉The  gametophyte bears unicellular or multicellular rhizoids for attachment with the substrate.

🔴Sex organs -

👉Gametophyte is well developed and bear sex organs. These sex organs  are multi-cellular and jacketed.

👉The male sex organ is anthredia and female sex organ is archegonia.

👉Anthredia produces antherozoids or male gamete whereas  archegonia produces eggs enclosed in its ventral canal cells.

👉Antherozoid use water as medium and reach to the egg for fertilization.

👉After the fusion, zygote is formed. This zygote  does not undergo reduction division and develops into multicellular sporophyte.

🔴Sporophyte-

👉Sporophyte is not  free living and depends on gametophyte for nutrition so it is attached with the gametophyte.

👉Sporophyte is  differentiated into foot, seta and capsule.

👉Capsule produces haploid spores by the reduction division. These spores germinate and form gametophyte.

👌👌Remember - Bryophytes have alternation of generation with the gametophyte and sporophyte.

🌑Importance of Bryophytes:

🔴Bryophytes, especially mosses, prevent soil erosion caused  by running water. They are also involved in the process of succession.

🔴Mosses are an important link in plant succession on rocky areas. They take part in binding soil in rock crevices formed by lichens. Growth of Sphagnum ultimately fills ponds and lakes with soil.

🔴Peat is a dark spongy fossilized matter of Sphagnum. Peat is dried and cut as cakes for use as fuel. Peat used as good manure. 

🔵Extra shot of Importance of Bryophytes

Mosses are a good source of animal food in rocky and snow covered  areas.Polytrichum  is used to remove kidney and gall bladder stones. Sphagnum is used for treatment of eye diseases

🌑Classification of Bryophytes-  

Bryophytes are classified into  three classes:
1. Hepaticae or Liverworts 
2. Anthocerotae  or Hornworts 
3.Musci  or Mosses 

🌑General features of  Liverworts.

🔴Liverworts are present in moist areas , at banks of rivers, damp, soil, bark of trees etc.

🔴Generally the gametophytic plant body is  thalloid. Thallus is dorsiventral Sometimes it is foliose or having tiny leaves without midrib.

🔴The leafy members have tiny leaf like appendages in two row on stem like structure.

🔴Asexual reproduction takes place by the fragmentation of thallus.

🔴They also reproduce asexually by the special structure called gemmae or Gemma cup. These are asexual buds that are green and multicellular. Gemmae originated on the thallus of liverworts.

🔴Sexual reproduction takes place in antheridia and archegonia. Both are located on different thallus or same thallus at the dorsal surface.

🔵Extra shot of Importance of Liverworts

Each cell in the thallus contains many chloroplasts; the chloroplasts are without pyrenoid. Sporophyte may be simple in Riccia having only a single capsule or differentiated into foot, seta and capsule in Marchantia. Spores are formed in capsule by meiosis. For Example - Riccia, Marchantia, Pallia and Porella.

🌑General features of  Musci or moss

🔴The dominant stage of moss is gametophyte that is differentiated into two stages - Protonema and leafy stage.

🔴Protonema is creeping, green stage and developed directly from the spores. 🔴Leafy stages are developed from the protonema. Leafy stages bear leaves like appendages and are attached with the soil by multicellular rhizoids.

🔴They reproduce vegetatively by fragmentation and budding of protonema. 🔴They do sexual reproduction by producing antheridia and archegonia as a result zygote is formed. The zygote divides by  meiosis and produces spores that develop into sporophytes.

🔴In mosses, sporophytes are divided into foot seta capsules and  more developed than other groups.

🔴It's capsule has a more advanced mechanism of spore dispersal. For Ex- Funeria, Polytrichum Sphagnum,

🔵Extra shot of Importance of Moss

Marchantia polymorpha has been used to cure pulmonary tuberculosis. Bryophytes are used as packing material for fragile goods, glass wares etc. Some bryophytes act as indicator plants. 

🌑General features of  Hornworts

🔴Gametophytic plant body is simple, thallus  like dorsiventral without air chambers. Each cell of the thallus possesses a single large chloroplast with a pyrenoid.

🔴Sporophyte is not completely dependent on gametophyte for its nourishment.

🔴It is differentiated into foot seta  and capsules. Seta is meristematic. Columella is present in a capsule.

🔴The sporophytes produce  spores, which play a key role in reproduction. Hornworts do not have  vascular tissue.Thallus has thread-like rhizoids to attach the plant’s substrate.

🔴Rhizoids also absorb water and minerals from the environment. Thallus also has a cyanobacteria called nostoc  as a symbiotic association with the hornwort.

🔴Nostoc supplies the hornwort with nitrogen in turn the hornwort supplies Nostoc with carbohydrates produced through photosynthesis.

🔴Hornworts have a life cycle that contains both sexual gametophyte and asexual sporophyte generations. The gametophyte stage is  the dominant generation Because it has  male sex organ or antheridium and the female sex organ, or archegonium. 🔴Male gamete or  antherozoids release from the antheridium and travel through the water and reach the archegonium, where they fertilize the eggs.

🔴Each fertilized egg develops into a diploid embryo that gives rise to sporophyte. Sporophytes produce  haploid spores. The spores are released into the environment and form a thallus like gametophyte. 🔴They also exhibit the alternation of generations. For Example - Anthoceros, , Folioceros, Megaceros, , Notothylas etc.

 1. Bryophytes are called amphibian of land plant because 
A. They are found in moist shady area in hills
B. Their life Cycle is completed into two stages.
C. They require water for fertilization and sexual reproduction.
D. They have alternation of generation in life cycle.
Answer : C  

2. Which of the following statement is correct about the Bryophytes.
A. Body of Bryophytes is thallus like and less differentiated than algae.
B.They have well developed root, stem and leaves.
C.They include liver worts and Hornworts only.
D.Thallus is attached to the substrate by unicellular and multicellular Rhizoids.
Answer: D  

3. How many statements are correct.
1. Bryophytes are grown in most shaded area in hilly area and in damp and humid area.
2. Thallus of Bryophytes is prostrate or erect.
3. The main plant body is gametophyte which is diploid and non Photosynthetic.
4. They have root like, stem like, and leaf like structure.
5. Sex organs of Bryophytes are multicellular.
A. Two     B.Three
C. Four     D. Five
Answer : C  

4. Which one of the following statement is not correct.
A. Anthredia is male sex organ and produce biflagellate antherozoids.
B. The sex organs in Bryophytes is unicellular and jacketed .
C. Archegonia is female sex organ which is flask shape and produce single egg.
D. Anthredia release antherozoids in water and make contact with egg of archegonium to form zygote.
Answer : B  

5. Which of the following pair is incorrect with respect to Bryophytes.
A. Antherozoids: Non - flagellate
B. Gametophyte: haploid
C. Sex organ : Multicellular
D. Rhizoids: Unicellular or Multicellular
Answer : A  

6. Which one of the following statement is not correct about the Bryophytes.
A. Zygote immediately divides by reduction divison and form unicellular sporophyte.
B. Sporophyte is not a free living and remain attach with gametophyte for nutrition.
C. Cells of sporophyte undergo reduction divison and form haploid spores.
D. Spores of sporophyte are germinated and form gametophyte.
Answer : A  

7. Consider the following event  of life cycle of Bryophytes and arrange them in sequential order.
1. Formation of multicellular sex organ in gametophyte.
2. Transfer of antherozoids into flask shape archegonium.
3. Development of haploid and Photosynthetic gametophyte.
4. Formation of haploid spore in capsule of sporophyte by meiosis.
5. Formation of Multicellular sporophyte from zygote.
A.1 - 2 - 4 - 5- 3
B.2-  1 - 3 - 4 - 5
C.1 - 2 - 3 - 4 - 5 
D.5 - 4 - 3 - 2 - 1
Answer : A  

8. Liverworts are found in the :
A. Bank of stream
B. Bark of tree 
C. Deep in Wood
D. All of the above.
Answer: D  

9. Which one of the following  pair is a liver worts.
A. Funeria and Sphagnum
B. Riccia and Sphagnum
C. Marchantia and Sphagnum
D. Riccia and Marchantia
Answer : D  

10. Which one of the following statement is not correct for the Liverworts.
A. The plant body of Marchantia is thalloid.
B. Leafy members of liverworts have leaf like appendages in multiple row on stem.
C.  Thallus is dorsiventral and attached to Substrate.
D. Asexual reproduction takes place fragmentation of thallus or Gemmae.
Answer: B  

11. Gemmae are special structure born on thallus of liverworts. Which of the following words are related to gemmae.
1. Green
2. Unicellular
3. Multicellular 
4. Sexual buds
5. Asexual buds
A. 1 , 2 and 4
B. 1  , 3 and 5
C. 1   2 and 5
D. 1 , 2 and 3 
Answer: B  

12. Which of the following statement is not correct.
A . Thallus of Liverworts is monocious because male and female thallus born on same thallus.
B. Sporophyte of liverworts is differentiated into Foot, Seta and Capsule.
C. Spore that develop into gametophyte, formed in capsule by meiosis.
D. Male and female sex organs are formed either on same thallus or different thalli.
Answer: A 


13. Consider the following statement  about the gametophyte of Mosses and select the correct code :
1. Gametophyte of mosses is differentiated into Protonema and leafy stages.
2. Leafy stage is directly  developed from spore of sporophyte.
3. Protonema stage is developed from secondary protonema.
4. Leafy stage of moss gametophyte is attached with soil through Multicellular and branched Rhizoids.
A. 1 and 2     B. 3 and 4
C. 2  and 3    D. 1 and 4 
Answer : D  

14. Protonema stage of Moss gametophyte directly develop from spore. Protonema stage are :
A. Creeping, green, branched and thalloid.
B. Creeping, non green, branched and thalloid .
C. Creeping,  green,  branched and filamentous
D. Creeping, non green, branched and filamentous.
Answer:  C 

15. Which of the following statements is not correct about the leafy stages of Moss gametophyte. 
A. It develops from secondary protonema as lateral bud.
B. It consists of spirally arranged leaf .
C. It is attached to soil through unicellular and branched rhizoids.
D.  This stage bears sex organs.
Answer:  C  

16. In Moss, Vegetative reproduction take place by secondary protonema through:
A. Fragmentation 
B.  Budding
C. Fission 
D. Fragmentation and Budding 
Answer: D  

17. Which of the following statement is not correct about the differences between Liverworts and Mosses. 
A.  Thallus of liverworts is attached to soil by unicellular Rhizoids and 
In Mosses by Multicellular Rhizoids.
B. Sporophyte  and spore dispersal mechanism  of Mosses is more advanced than liverworts.
C. Sporophyte of liverworts and Mosses is differentiated into Foot  Seta and Capsule.
D. In capsule of sporophyte, liverworts and Mosses produce spore by Mitosis and meiosis respectively. 
Answer: D  


18. Which one of the following is not a Moss.
A. Marchantia 
B. Polytrichum 
C. Sphagnum
D.Funeria
Answer : A  

19. Consider the following statements and select the correct code:
1. Bryophytes play an important role in plant succession on bare rock or soil.
2. Some Mosses are used food for herbaceous mammals and other animals.
3. Some Mosses form dense mats on soil and reduce the impact of rain and prevent soil erosion. 
A. 1 and 2       B.2 and 3 
C. 1 and 3       D.  1, 2 and 3
Answer: D  


20. Consider the following statement and select the correct code:
1. Moss along with lichen are first community to establish on bare rock.
2. They decompose rock and form suitable condition for the growth of plants.
A. Only 1   B . Only 2
C. Both 1 and 2
D. Neither 1 nor 2
Answer:  C  

21. Which one of the moss is used as fuel and packing materials for transshipment of living material due to water holding capacity.
A. Funeria
B. Polytrichum
C. Sphagnum 
D. Anthoceros.
Answer: C  




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