Test: Plant Kingdom - 1 - NEET MCQ

1. Pinus - Dioecious: Pinus species are actually monoecious, meaning that both male and female cones are present on the same tree. Therefore, this statement is a mismatch.

2. Cycas - Dioecious: Cycas, a type of cycads, is indeed dioecious, meaning male and female reproductive structures are on separate individuals. This statement is correct.

3. Salvinia - Heterosporous: Salvinia, a genus of aquatic ferns, is indeed heterosporous, meaning it produces two types of spores: microspores and megaspores. This statement is correct.

4. Equisetum - Homosporous: Equisetum, commonly known as horsetails, is indeed homosporous, producing only one type of spore that develops into a bisexual gametophyte. This statement is correct.

Thus, the mismatch is:

(1) Pinus - Dioecious

In Bryophytes, the sporophyte does not have a free-living stage. It is dependent on the gametophyte for nutrition and support. This contrasts with other plant groups like Pteridophytes and Gymnosperms, where the sporophyte is the dominant, free-living stage of the life cycle.

Line in NCERT: "The main plant body of the bryophyte is haploid. It produces gametes, hence is called a gametophyte."

I. The stem is branched: This is generally true for many species of Pinus. Pines typically have branched stems, although the branching pattern can vary depending on the species and age of the tree.

II. Roots have fungal association in the form of mycorrhiza: This is also true. Pine trees form a mycorrhizal association with fungi. This symbiotic relationship is crucial for the tree's nutrient uptake, particularly in nutrient-poor soils.

III. The male and female strobili are borne on different trees: This statement is false. In Pinus, the male (pollen cones) and female (seed cones) strobili are typically borne on the same tree. Pines are monoecious, meaning they have both male and female reproductive structures on the same individual.

So, the correct statements about Pinus are I and II.

Line in NCERT: "The roots in some genera have fungal association in the form of mycorrhiza (Pinus), while in some others (Cycas) small specialised roots called coralloid roots are associated with N2- fixing cyanobacteria. The stems are unbranched (Cycas) or branched (Pinus, Cedrus)."

Asexual reproduction in liverworts takes place by fragmentation of thalli, or by the formation of specialised structures called gemmae (sing. gemma). Gemmae are green, multicellular, asexual buds, which develop in small receptacles called gemma cups located on the thalli. The gemmae become detached from the parent body and germinate to form new individuals.

Line in NCERT: "Asexual reproduction in liverworts takes place by fragmentation of thalli, or by the formation of specialised structures called gemmae (sing. gemma)."

• Pteridophytes are most primitive vascular flowerless, spore-producing cryptogamic land plants, commonly called vascular cryptogams.
• They are sometimes called as Amphibians/botanical snakes/spore producing seedless tracheophytes.
• They are the first vascular land plants to have an independent sporophyte diploid plant body with true root, stem and leaves.
• In contrast bryophytes, the amphibians of the plant kingdom are devoid of true roots, stem, and leaves, with no vascular supply but root-like, non-vascular rhizoids, leaf-like, and stem-like structures are present.

Hence, the correct option is C.
NCERT Reference: Topic “PTERIDOPHYTES” of chapter Plant Kingdom. 

Line in NCERT: "The Pteridophytes include horsetails and ferns. Evolutionarily, they are the first terrestrial plants to possess vascular tissues - xylem and phloem."

Cycas is classified as a gymnosperm due to the presence of its ovule which is naked . All gymnosperms produce naked seed due to the naked ovule, which distinguishes them from angiosperms.

Fig: Cycas
Hence, the correct option is C.
NCERT Reference: Topic “GYMNOSPERMS” of chapter Plant Kingdom.

Line in NCERT: "The seeds that develop post-fertilisation, are not covered, i.e., are naked."

In liverworts:The sporophyte is differentiated into a foot, seta and capsule. After meiosis, spores are produced within the capsule. These spores germinate to form free-living gametophytes.

In mosses:After fertilisation, the zygote develops into a sporophyte, consisting of a foot, seta and capsule. The sporophyte in mosses is more elaborate than that in liverworts. The capsule contains spores. Spores are formed after meiosis. The mosses have an elaborate mechanism of spore dispersal

Line in NCERT: "The sporophyte is differentiated into a foot, seta and capsule."

• The common forms of Brown algae or Phaeophyceae are Ectocarpus, Dictyota, Laminaria, Sargassum and Fucus. 
• The brown color of these algae is due to xanthophyll pigment called fucoxanthin.
• Laminaria is also called kelp. It is the largest and most complex brown algae.

Hence, the correct option is B
NCERT Reference: Topic “Phaeophyceae” of chapter Plant Kingdom.

Line in NCERT: "The common forms are Ectocarpus, Dictyota, Laminaria, Sargassum and Fucus."

• Heterospory refers to the production of spores of two different sizes and developmental patterns: microspores for males and megaspores for females.
• Genera like Selaginella and Salvinia which produce two kinds of spores, macro (large) and micro (small) spores are known as heterosporous.

Fig: Heterosporous pteridophytes

Hence, the correct option is D.
NCERT Reference: Topic “PTERIDOPHYTES” of chapter Plant Kingdom.

Line in NCERT: "Genera like Selaginella and Salvinia which produce two kinds of spores, macro (large) and micro (small) spores, are known as heterosporous."

The pteridophytes are further classified into four classes: Psilopsida (Psilotum); Lycopsida (Selaginella, Lycopodium), Sphenopsida (Equisetum) and Pteropsida (Dryopteris, Pteris, Adiantum).

• Liverworts are a group of non-vascular plants similar to mosses.
• They are unlike most plants we are familiar with because they don't produce seeds, flowers, fruit, or wood, and they don't even have vascular tissue.
• For reproduction, liverworts create spores instead of seeds. The bryophytes are divided into liverworts and mosses. So they are closely related to each other.

Fig: Mosses
Hence, the correct option is B.
NCERT Reference: Topic “BRYOPHYTES” of chapter Plant Kingdom.

Line in NCERT: "The bryophytes are divided into liverworts and mosses."

Cycads are known for their specialized coralloid roots, which harbor symbiotic cyanobacteria capable of nitrogen fixation. This symbiotic relationship allows cycads to thrive in nitrogen-poor soils, as the cyanobacteria convert atmospheric nitrogen into a form that the plants can use. This mutualistic interaction is crucial for the nutrient uptake of cycads, making the reason a correct explanation for the assertion.

Line in NCERT: "small specialised roots called coralloid roots are associated with N2- fixing cyanobacteria."

Many species of Porphyra, Laminaria and Sargassum are among the 70 species of marine algae used as food.

The predominant stage of the life cycle of a moss is the gametophyte which consists of two stages. The first stage is the protonema stage, which develops directly from a spore. It is a creeping, green, branched and frequently filamentous stage. The second stage is the leafy stage, which develops from the secondary protonema as a lateral bud. They consist of upright, slender axes bearing spirally arranged leaves. They are attached to the soil through multicellular and branched rhizoids. This stage bears the sex organs.

Line in NCERT: "The predominant stage of the life cycle of a moss is the gametophyte which consists of two stages. The first stage is the protonema stage, which develops directly from a spore. The second stage is the leafy stage, which develops from the secondary protonema as a lateral bud."

Topic in NCERT: Chlorophyceae

Line in NCERT: "The pigments are localised in definite chloroplasts. Most of the members have one or more storage bodies called pyrenoids located in the chloroplasts. Green algae usually have a rigid cell wall made of an inner layer of cellulose and an outer layer of pectose."

Assertion (A) is true because heterospory (the production of two types of spores, microspores and megaspores) is an evolutionary step that led to the development of seeds in higher plants. Reason (R) is also true as it correctly describes the role of megaspores and microspores in heterosporous ferns. However, while (R) is true, it is not the direct explanation of how heterospory led to the evolution of seeds, which involves more complex evolutionary transitions beyond just the production of different spore types.

Line in NCERT: "The megaspores and microspores germinate and give rise to female and male gametophytes, respectively. This event is a precursor to the seed habit considered an important step in evolution."

The archegoniophore is a specialized structure in liverworts like Marchantia that bears the archegonia (female reproductive organs). It is not present in Chara (a green alga), Adiantum (a fern), or Funaria (a moss).

Line in NCERT: "Archegonium is flask-shaped and produces a single egg."

- Statement 1: Gymnosperms have naked ovules, not enclosed ones. This is false.
- Statement 2: Angiosperms have seeds that are enclosed in fruits, not unenclosed. This statement is  true.
 

Line in NCERT: "Unlike the gymnosperms where the ovules are naked, in the angiosperms or flowering plants, the pollen grains and ovules are developed in specialised structures called flowers. In angiosperms, the seeds are enclosed in fruits."

1. Fungal association in the form of mycorrhiza is not characteristic of Cycas but of Pinus.

2. Coralloid roots in Cycas are associated with N2-fixing cyanobacteria, not in Pinus.

Line in NCERT: "Roots in some genera have fungal association in the form of mycorrhiza (Pinus), while in some others (Cycas) small specialised roots called coralloid roots are associated with N2- fixing cyanobacteria."