NEET Biology Plant Kingdom MCQs Set 21

Answer: (b) megaspore, pollen grain and endosperm

Explanation:
1. In Pinus the haploid structures are the megaspore, the pollen grain (microspore) and the endosperm (female gametophyte). The embryo and integument are diploid.

Teacher's Note:
1. Pinus is a heterosporous gymnosperm.
2. Gymnosperm endosperm is formed before fertilisation and is haploid.

Answer: (d) Pteris archegonia release chemical to attract its sperms

Explanation:
1. Pteris archegonia release a chemical (malic acid) that attracts only Pteris sperms. This is chemotaxis.

Teacher's Note:
1. Different species use different attractants.
2. Funaria sperms do not respond to it.

Answer: (a) heterosporous nature

Explanation:
1. Selaginella is heterosporous, producing microspores and megaspores, which is a step toward the seed habit.

Teacher's Note:
1. Rhizophores, strobili and ligules are also seen in Selaginella.
2. Heterospory is considered evolutionarily important.

Answer: (a) spore dispersal

Explanation:
1. The peristome teeth of moss capsules are hygroscopic and help in gradual dispersal of spores.

Teacher's Note:
1. Peristome is present at the mouth of the capsule.
2. It prevents sudden release of all the spores.

Answer: (a) lower part

Explanation:
1. The apophysis is the lower sterile part of the capsule of Funaria, below the theca.

Teacher's Note:
1. The capsule is made of apophysis, theca and operculum.
2. Spores are produced in the theca.

Answer: (b) Funaria

Explanation:
1. The protonema is a green filamentous stage that develops from a moss spore and bears the leafy gametophore; Funaria has one.

Teacher's Note:
1. Chlamydomonas, Riccia and Spirogyra do not form a protonema.
2. Protonema is the juvenile gametophyte.

Answer: (a) zygospore

Explanation:
1. The zygote of Spirogyra is a thick-walled zygospore. The zygote after fertilisation of Chlamydomonas is a zygospore too, as it is isogamous.

Teacher's Note:
1. Oospore is formed from oogamy.
2. Zoospores are asexual spores.

Answer: (a) isogamous

Explanation:
1. The common sexual reproduction in Chlamydomonas is isogamous (gametes of equal size). Some species show anisogamy or oogamy.

Teacher's Note:
1. Isogamy is the primitive type.
2. Volvox shows oogamy.

Answer: (d) Moss

Explanation:
1. The gametophyte is largest in the moss among the options. Cycas, Selaginella and angiosperms have very reduced gametophytes.

Teacher's Note:
1. In bryophytes the gametophyte is the dominant phase.
2. It reduces from bryophytes to angiosperms.

Answer: (a) they require a layer of water for carrying out sexual reproduction

Explanation:
1. Bryophytes are called amphibians of the plant kingdom since they need water for fertilisation, though they live on land.

Teacher's Note:
1. The male gametes swim in a film of water.
2. They need damp places.

Answer: (c) Bryophyta

Explanation:
1. Bryophyta produce spores and embryos but lack vascular tissue and seeds. Pteridophytes have vascular tissue.

Teacher's Note:
1. Algae have no embryos.
2. Bryophytes are called non-vascular embryophytes.

Answer: (c) 6

Explanation:
1. The pollen grain is a microspore (n = 6). The endosperm in Pinus is the female gametophyte and is also haploid, so it also has 6 chromosomes.

Teacher's Note:
1. Endosperm of angiosperms is triploid.
2. Gymnosperm endosperm forms before fertilisation.

Answer: (d) gymnosperms

Explanation:
1. Gymnosperms bear naked seeds but have no flowers or fruits.

Teacher's Note:
1. Pteridophytes and bryophytes have no seeds.
2. Angiosperms have flowers and fruits.

Answer: (b) Pinus

Explanation:
1. Resin and turpentine are obtained from Pinus.

Teacher's Note:
1. Pinus wood is soft.
2. The resin is used in varnishes.

Answer: (d) Roots

Explanation:
1. Funaria has no true roots (only rhizoids), whereas Selaginella has roots. Both have archegonia, embryos and flagellate sperms.

Teacher's Note:
1. Roots are first found in pteridophytes.
2. Bryophytes have rhizoids.

Answer: (c) Chlamydomonas

Explanation:
1. In Chlamydomonas the plant body is haploid; the zygote is the only diploid (sporophytic) phase, and it undergoes meiosis on germination.

Teacher's Note:
1. Chlamydomonas is haplontic.
2. The others have a distinct sporophyte.

Answer: (c) zygospore germination

Explanation:
1. In Ulothrix and Spirogyra meiosis occurs during the germination of the zygospore, as these are haplontic.

Teacher's Note:
1. Gametes form by mitosis.
2. Haplontic life cycles have zygotic meiosis.

Answer: (b) well developed vascular system

Explanation:
1. Pteridophytes have a well-developed vascular system (xylem and phloem), unlike bryophytes.

Teacher's Note:
1. Both groups have archegonia and flagellate sperms.
2. The sporophyte is dominant in pteridophytes.

Answer: (d) starch

Explanation:
1. Pyrenoids are centres of starch formation in algae.

Teacher's Note:
1. They are proteinaceous bodies in the chloroplast.
2. Porphyra is a red alga.

Answer: (b) cup-shaped

Explanation:
1. The chloroplast of Chlamydomonas is a single cup-shaped chloroplast.

Teacher's Note:
1. Spirogyra has a spiral chloroplast and Zygnema a stellate one.
2. Ulothrix has a collar-shaped chloroplast.

Answer: (c) ovules not enclosed in ovary

Explanation:
1. Pinus is a gymnosperm with naked ovules not enclosed in an ovary, unlike mango, an angiosperm.

Teacher's Note:
1. Both have tree habit and wood.
2. Angiosperms have an ovary and a fruit.

Answer: (d) Pinus

Explanation:
1. Pinus (a gymnosperm) is the most advanced among them because it has seeds and a dominant sporophyte.

Teacher's Note:
1. Selaginella is a pteridophyte and Funaria a bryophyte.
2. Chlamydomonas is a simple alga.

Answer: (c) surface of ovuliferous scale

Explanation:
1. The wing of the Pinus seed is formed from the surface of the ovuliferous scale.

Teacher's Note:
1. It helps in wind dispersal.
2. It is not part of the testa.

Answer: (b) have sporophyte attached to gametophyte

Explanation:
1. The unique feature of bryophytes is that the sporophyte is attached to the gametophyte and depends on it for nutrition.

Teacher's Note:
1. Many other groups also make spores.
2. Other plants have free-living sporophytes.

Answer: (b) isogamy, anisogamy and oogamy

Explanation:
1. Chlorophyceae show isogamy, anisogamy and oogamy in different genera.

Teacher's Note:
1. Spirogyra is isogamous and Volvox oogamous.
2. Isogamy is the most primitive.

Answer: (c) Spirogyra

Explanation:
1. Nostoc, Anabaena (cyanobacteria) and Azotobacter fix nitrogen. Spirogyra is a green alga and cannot.

Teacher's Note:
1. Only prokaryotes fix nitrogen.
2. Nitrogenase is the key enzyme.

Answer: (a) red algae

Explanation:
1. Agar is obtained from red algae such as Gelidium and Gracilaria.

Teacher's Note:
1. Algin comes from brown algae.
2. Agar is used to make culture media.