Question

Riccia is a bryophyte due to-
A) Thalloid
B) Rhizoids
C) Alternation of generation
D) Dependent sporophyte

Answer 1

Hint:In bryophytes, the sporophyte is present on the gametophyte.The gametophyte in bryophytes provides nutrition to the sporophyte.

Complete answer:
Riccia is a bryophyte.Bryophytes have sporophytes which develop on the gametophyte.It is formed after syngamy and is dependent on the gametophyte for nutrition.A dependent sporophyte is a characteristic feature of bryophytes.

Additional information: Bryophytes are usually known as amphibians of the plant kingdom, as they require water for sexual reproduction even if they live on land.There are two groups present in bryophytes; Mosses and liverworts.Bryophytes have more differentiated bodies in comparison to algae.They have prostate or erect alignment of thallus which are attached to the substratum via rhizoids.Bryophytes lack true roots, stem and leaves.Instead of these structures, foot, seta and capsule are present.the main gametophyte is haploid which produces gametes.Anthredium and archegonium are present as male and female sex organs respectively.The sex organs are also multicellular.A diploid zygote forms on the fusion of gametes.Instead of directly undergoing reduction division, it produces a sporophyte which is multicellular and remains attached to the gametophyte to receive nourishment.

Several cells from the sporophyte undergo reduction division in order to produce haploid spores.The spores are released and under favourable conditions, they germinate and give rise to a gametophyte.Talking about the alternation of generation, bryophytes exhibit intermediate haplo-diplontic type of life cycle where haplontic phase dominates the diplontic phase which is short living.

Therefore, the correct answer is- D.dependent sporophyte.

Note:Bryophytes are differentiated into mosses and liverworts on the basis of body arrangement.Mosses have an upright axis which is slender and bear spirally arranged leaf like structures while liverworts have dorsi-ventral thalloid plant body.