Test: Plant Kingdom 5 - From Past 28 Years Questions - NEET MCQ

 Isogamy involves the fusion of gametes which are morphologically and physiologically similar. They are called isogametes. In Chlamydomonas, two vegetative cells may fuse to form a zygospore and the phenomenon is called as hologamy. As a result of fusion of two gametes, zygospore is formed

When prothallus of a fern give rise to sporophyte directly from somatic cell without forming gametes it is Apogamy. Such type of sporophyte is haploid in nature.
Development of gametophyte directly from sporophyte without meiosis and without forming spores, is Apospory.

In Gymnosperms like Cycas/Pinus, endosperms of female gametophyte is haploid and formed before fertilizaiton.
In angiosperms endosperm is triploid and develops after fertilization.

Presence of two types of spores microspores and megaspores (Heterospory) is the evolutionary characteristic in the life cycle of Selaginella.

Archegonia of a particular species recognises antherozoids (sperms) of the same species through release of chemical. In Pteris, archegonia produces malic acid which attracts sperms of Pteris only for fertilization.

Pinus and in all other Gymnosperms endosperm produced before fertilization and is haplolid. Megaspore and pollen grain are initial structures of female gametophyte and male gametophyte respectively hence, they are haploid.

Capsule of the Funaria differentiated into : (1) Operculum – upper part -lid (2) Theca – Middle – fertile part (3) Apophysis – lower -photosynthetic

 Peristomes are teeth present in the capsule of moss. These are in two rows and helps in the dispersal of the spores due to hygroscopic nature.

In Funaria, the spore germinates to form a green multicellular structure called as protonema which later on develops into gametophyte. Presence of protonema is characteristic feature of moss.

In both the members of green algae, Spirogyra and Chlamydomonas, gametes are fused to form zygote which develops into a thick walled resting zygospore.
Zoospore is asexual spore while Oospore is sexual spore.

In Chlamydomonas, sexual reproduction takes place through : (1)Isogamy : Fusion of 2 similar gametes. (2)Anisogamy : Fusion between morphological similar but physiologically different gametes. (3)Oogamy : Fusion between two dissimilar gametes. (4)Hologamy : Fusion of two young cells. Most common mode is isogamy.

As one moves from thallophyta → Bryophyta → Pteriodophyta → Gymnosperm → Angiosperms, there is reduction in the gametophyte and elaboration of sporophyte.
Hence, in this question moss has largest gametophyte Moss → Selaginella → Cycas → Angiosperm → Reduction in Gametophyte.

Bryophytes are amphibians because they complete their vegetative phase on land but water is necessary for their reproductive phase.

The plant body of Chlamydomonas is gametophyte (haploid). It reproduces asexually by zoospore formation and sexually by gametes. Gametes are isogametes which fuses to produce diploid zygote which is the only structure representing sporophytic generation. In Pinus main plant body is sporophyte same is the case with Selaginella and Dryopteris.

Bryophytes are the plants which produces spores and embryo but no vascular tissues are present, although primitive type of conducting tissues are present in the form of hadrome and leptome.

• Rhodophytes     &     phaeophytes     are     algae     produces    spores,    no    embryo    &    vascular     tissue
• Pteridophytes     have     spores,     embryo     and     true vascular tissues.

Funaria is moss (Bryophyte) possesses archegonium, embryo, flagellated sperms. These are also present in Selaginella (Pteriodophyte) but it also has roots which are absent in Funaria.

Gymnosperms are vascular land plants having naked ovules i.e., ovules are not enclosed in a ovary hence, flower is absent. Ovules after fertilization produces  naked seeds. Pteridophytes (ferns) and mosses do not produce seed.

Pollen grains are haploid (n). If haploid no. of chromosomes are 6 then endosperm will also have 6 chromosomes as it is formed before fertilization and is haploid.

Pinus species → Resins and turpentine Cedrus → Timber for railway sleepers Abies → Paper, canada balsam.
Cycas → ornamental plant

Turpentine is extracted from the wood (xylem) of Pinus (Gymnosperm).
Turpentine is a fluid obtained by the complex distillation of resin obtained from trees, mainly various species of pine (Pinus). It is composed of terpenes, mainly the monoterpenes alpha-pinene and betapinene. Turpentine oil is obtained by boiling resin at 155 degrees Celsius in large tubs. It has a potent odor that is similar to that of nail polish remover.

Well developed vascular system present in the members of Pteridophytes but absent in mosses as the plant body is sporophyte which is distinguished into true root, stem and leaves. Independent gametophyte, archegonia flagellate spermatozoids are present in moss and pteridophyte both.

Plant body of Ulothrix and Spirogyra is gametophyte (haploid), they produce zoogametes(n) which fuses to form zygospore (2n) diploid, which is a resting spore. On set of favourable condition zygospore undergoes reductional division or meiosis to produce zoospores which give rise to new plant.

Shape and number of chloroplast in different member of algae is different Chlamydomonas – cup shaped, 1/cell Zygnema –  Stellate, 2/cell Spirogyra – Spiral, 1/ cell Ulothrix  – Collar shaped, 1/cell

In cell biology, pyrenoids are centers of carbon dioxide fixation within the chloroplasts of algae and hornworts. Pyrenoids are not membrane-bound organelles, but specialized areas of the plastid that contain high levels of ribulose-1,5-bisphosphate carboxylase/ oxygenase (RubisCO). RubisCO fixes carbon dioxide by adding it to the 5-carbon sugar-phosphate, ribulose-1,5-bisphosphate, yielding two molecules of the 3-carbon compound, 3-phosphoglycerate. In a competing reaction, the enzyme uses oxygen to break down ribulose-1,5-bisphosphate to phosphoglycolate and 3-phosphoglycerate, with no net fixation of carbon. 

Pinus is a gymnospermic plant which has a well developed conducting tissue system but seeds are naked. Whereas mango is an angiospermic plant in which seed are enclosed in the ovary and fruit is present.