Practice Corner MCQs

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(d) Artificial systems of classification were based upon morphological characters (such as habit, habitat, colour, number, and shape of leaves, etc.) for grouping of organisms. They were mainly based on vegetative characters or on the androecium structure. These systems separated the closely related species since they were based only on a few characteristics.

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(a) Artificial systems of classification were based upon morphological characters such as habit, habitat, colour, number, and shape of leaves, etc.) for grouping of organisms. They were mainly based on vegetative characters or on the androecium structure. These systems separated the closely related species since they were based only on a few characteristics.

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(a) Artificial systems of classification were based upon vegetative and sexual characteristics, where both vegetative and sexual characteristics were given equal weightage. It was not acceptable because vegetative characters are more easily affected by the environment.

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(d) Numerical taxonomy evaluates resemblances and differences or primitiveness and advancement through statistical methods based on a large number of characters obtained from all disciplines of biology. This is followed by assigning them number and code of computer like plus \((+)\) minus \((-)\) followed by computer analysis. In this way, each character is given equal importance and at the same time hundreds of characters can be considered.

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(b) Natural system of classification takes into consideration comparable study of number of characters so as to bring out natural similarities and dissimilarities and hence natural relationships among the organisms. They include morphological characters, anatomical characters, cytological characters, physiology, ontogeny or development, reproduction, cytochemistry and biochemistry, experimental taxonomy, etc.

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(d) The natural system of classification takes into consideration comparable study of a number of characters so as to bring out natural similarities and dissimilarities and hence natural relationships among the organisms. They include morphological characters, anatomical characters, cytological characters, physiology, ontogeny or development, reproduction, cytochemistry and biochemistry, experimental taxonomy, etc. So, the correct answer is ‘All of the above’.

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(d) There are three systems of classification, namely artificial, natural, and phylogenetic. In natural system of classification, a large number of traits are considered. It is based on morphological, anatomical, cytological, physiological and biochemical characteristics of the organisms. The artificial system of classification is based on observable characteristics of the organisms. The phylogenetic system of classification is based on genetic and phylogenetic relationships between organisms.
Thus, the correct answer is option d.

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(c) bringing out similarities and dissimilarities.

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(c) Classification based on evolutionary relationships of organisms is called phylogenetic system of classification.

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(a) Artificial system: It was proposed by Carolus Linnaeus, known as the father of systematic botany”. Classification without basing on the relationship among plants.

Natural system: George Bentham and Joseph Dalton Hooker proposed this system of classification. Here classification is based on the form or natural relationship between plants.
Phylogenetic system: This system contains fourteen major divisions. It is to be understood that the monocots are primitive than the dicots.
So,the correct answer is ” (A) – (ii),(B) – (i),(C) – (iii) “.

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(c) Chemotaxonomy is based upon the characteristics of various chemical constituents of organisms. Chemical constituents of plant species have been found to be unvarying and do not change easily. Chemical characters have also helped in establishing relationships and statistical evaluation of taxonomic information.

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(d) At the same time hundreds of characters can be considered.

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(a) Cryptogamae refers to plants without seeds and Phanerogamae refers to plants with seeds. Algae and bryophytes are non-vascular cryptogams. Pteridophytes are vascular cryptogams. Gymnosperms and angiosperms are phanerogams.

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(d) Tracheophyta are those plants which possess conducting or vascular tissues, xylem and phloem. Xylem transports water and minerals while phloem conducts organic food. Tracheophytes include pteridophytes, gymnosperms and angiosperms.

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(b) The correct option is: A – Dictyota B – Polysiphonia
Dictyota is a ribbon shaped dichotomous and marine, brown algae that grows in shallow water. Polysiphonia is a marine red alage which is attached to substratum by rhizoids and holdfast.

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(b) Phaeophyta, also known as brown alga is a marine alga constituted of chlorophyll including brown pigments. It is present in diverse forms in nature and is often of gigantic size. The main body i.e. thallus of this alga is composed of three sections including holdfast, blade, and stipe. The blade or fronds are responsible for the process of photosynthesis. Some species may have an air bladder supporting their floatation on the water surface.

Hence, the correct option is (A) – Frond, (B) – Stipe, (C) – Holdfast

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(a) Spirogyra is a filamentous algae, commonly found in freshwater, ditches, and ponds. It is also known as pond silk, as it’s filament shine like a silk thread due to the presence of mucilage.

Chlamydomonas is a green algae found in stagnant water and damp soil and also in fresh and sea water, even in snow as ” snow algae “. It is a unicellular flagellate.
Volvox green algae and forms spherical colonies. They live in freshwater habitats.
Kelps are the large brown algae and grow in underwater forests or kelp forests, in shallow oceans. They may develop dense forests with high production biodiversity.
So, the correct answer is ” A – (ii), B – (i), C – (iii), D – (iv)”.

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(c) Form and size of algae range from microscopic unicellular forms like Chlamydomonas, to colonial forms like Volvox and to filamentous forms like Ulothrix and Spirogyra.

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(a) In isogamy, both the fusing gametes are morphologically and physiologically similar.

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(d) In anisogamy the fusing gametes differ in size and behaviour. One of the two gametes is larger and is called macrogamete or female gamete; the other is smaller and is termed microgamete or male gamete. In oogamy, there is a large food laden non-flagellate female gamete called egg or oosphere whereas the male gamete or antherozoid is smaller and motile. Oogamy is the familiar form of sexual reproduction, it is a form of anisogamy (heterogamy).

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(c) Volvox is the fresh water green algae that grows on the surface of water bodies. During rainy seasons, they grow fast making the surface to appear in green color. Volvox reproduces both sexually and asexually. The sexual reproduction type is Oogamous type.

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(c) Nearly 50% of total carbon dioxide fixation is carried out by algae through photosynthesis. Photosynthesis by algae releases oxygen in the immediate aquatic environment. It is essential for respiration of aquatic life.

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(a)  A-(ii), B-(iii), C-(i), D-(iv)

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(d) Agar is gel-like non-nitrogenous extract obtained from red algae. It is used as a medium in the cultures of bacteria, fungi and other microorganisms and also in numerous industrial processes, e.g., food, bakery, cosmetics, leather, textile industries, in confectionery, etc.

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(a) Chlorella (Green alga), as food supplement is rich in protein and carbohydrates. It yields about 30% proteins, 15% lipids, 30% carbohydrates and 5% ash. Spirulina (blue-green alga) is one of the richest sources of protein and vitamin \(B_{2}\). In long range space exploration, scientist have turned to Chlorella and Spirulina to use them as portable oxygen generators and food sources.

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(a) Major photosynthetic pigments in green algae are chlorophyll a and b

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(b) A single cup-shaped chloroplast is characteristic of Chlamydomonas. It occupies the major portion of the cell and is thick at the base while its sides are relatively thin and projected upward.

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(a) Pyrenoids are cellular micro-compartments that are not membrane bound organelles. Pyrenoids are found within chloroplast. Chloroplasts generally contain one to many pyrenoids for storage of starch.

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(d) Cell wall of green algae is thin, transparent and firm and consists of outer pectic and inner cellulosic layer.

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(d) Chlorophyceae are also known as green algae. In such algae chloroplasts contain pigments like chlorophyll – a, b, carotene and xanthophyll. Their cell is made up of cellulose. Reserve food in such algae is in the form of starch. Examples are Chlamydomonas, Volvox, Ulothrix, Chlorella etc. So, the correct answer is ” All of these “.

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(b) Volvox is colonial green alga. The cells are like unicellular alga Chlamydomonas and are definitely organised in the form of a colony called coenobium. The coenobia of Volvox are largest, highly differentiated and well evolved among motile forms. Each coenobium is motile, the movement is brought about by the joint action of the flagella of individual cell.

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(a) In Ulothrix, sexual reproduction takes place by the fusion of biflagellate gametes from different filaments. Ulothrix like Chlamydomonas shows the simplest and primitive type of sexual reproduction or Isogamy where two morphologically identical flagellated gametes take part in fusion resulting in zygospores.

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(c) Volvox is colonial green alga. The cells are like unicellular alga Chlamydomdnas and are definitely organised in the form of a colony called coenobium. The coenobia of Volvox are largest, highly differentiated and well evolved among motile forms. Each coenobium is motile, the movement is brought about by the joint action of the flagella of individual cell.

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(b) Brown algae or Phaeophyta include about 2000 species. Most of them are marine except few, e.g. Pleurocladia, Heribandiella and Bodanella, which are found in freshwater in European countries.

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(c) The members of Phaeophyceae or brown algae possess chlorophyll a, chlorophyll c, carotenoids and xanthophyll. They vary in colour depending upon the amount of the xanthophyll pigment, fucoxanthin present in them.

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(d) Seaweeds are large multicellular algae living in the sea or in intertidal zone. They are common species of the Chiorophyta, Rhodophyta and Phaeophyta. The seaweeds are a polyphyletic group. Seaweeds, especially brown algae, are used as food for domestic animais in different parts of the world. Sargassum, Fucus and Laminaria are eaten by cattle in Scotland, Ireland and Iceland. Macrocystis sp. and other kelps being rich in vitamins \(\mathrm{A}\) and \(\mathrm{E}\) are served as cattle fodder.

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(b) The food in the members of Phaeophyceae is stored as complex carbohydrates in the form of laminarin or mannitol.

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(d) Vegetative reproduction takes place by fragmentation. First propagules are developed and then after detachment new plants are formed. Asexual reproduction takes place by biflagellate pear-shaped zoospores. Sexual reproduction ranges from isogamy to oogamy through anisogamy. Gametes al bears 2 laterally attached flagella. In most of the members, fertilization is external.

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(d) The members of Rhodophyceae are commonly called red algae because of the predominance of the red pigment r-phycoerythrin in their body. Apart from this, other major pigments found in them are chlorophyll \(a\) and chlorophyll \(d\).

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(b) Phycoerythrin is present in Rhodophyceae or red algae, e.g., Polysiphonia.

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(d) The members of Rhodophyceae are commonly called red algae because of the predominance of the red pigment r-phycoerythrin in their body. Apart from this, other major pigments found in them are chlorophyll a and chlorophyll d.

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(b) Sexual reproduction in Rhodophyceae is oogamous. Sexual reproduction takes place by non-motile gametes.

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(a) Batrachospermum is a freshwater red alga widely distributed in tropical, sub-tropical, and temperate areas. Gelidium amansii is an economically important species of red algae commonly found in the shallow cost of many East and Southeast Asian countries.

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(d) Chlorophyceae have reserve food in the form of starch. Their cell wall is made up of cellulose. Phaeophyceae have reserve food in the form of laminarin and mannitol. The cell wall is composed of a mixture of polysaccharides like cellulose, pectose, and algin.

Rhodophyceae have a cell wall composed of cellulose, pectin, and sulfated phycocolloids. They have reserved food as floridean starch.
So, the correct answer is “All of these “.

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(d) Chlorophyceae is a green algae which has chlorophyll a and b type. They have flagella apical and equal about two to eight in number. The reserve food material is starch.
Phaeophyceae is a brown algae which has chlorophyll a and c type. They have flagella lateral and unequal about two in number. The reserve food material is laminarin.

Rhodophyceae is a red algae which has chlorophyll a and d type. They do not have motile stage. The reserve food material is floridean starch.

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(a) The algae shown in the given figure are Volvox, Chlamydomonas, and Ulothrix, respectively. They belong to Class Chlorophyceae.

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(c) Bryophytes are divided into liverworts, hornworts, and mosses. Liverworts may be thallose or foliose, but mosses are always leafy.

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(a) The structure of Bryopsida mainly mosses consists of two body parts including gametophyte and sporophyte.
The spore capsule has a supporting branch which is the sporophytic part of moss and this part arises from the protonema part known as a gametophyte. The leaf, stem, gametophore, and protonema together form the gametophyte. Hence, the correct option is (A) – Sporophyte, (B)-Gametophyte

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(c) Marchantia is dioecious plant, sex organs borne on stalked upright receptacles or gametophores. Gametophore of the male thallus is called antheridiophore having a stalk and an 8-lobed male receptacle. Gametophore of female thallus is called archegoniphore. Its receptacle has nine cylindrical processes or rays.

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(b) Plant shown in the figure is Sphagnum. It is a bryophyte, commonly called as peat moss.

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(a) Bryophytes are known as ‘amphibians of plant kingdom’. In their vegetative structure, bryophytes have become adapted to land but they depend on water for sexual reproduction because the swimming habit is retained by their sperms.

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(a) Bryophytes are usually found in damp, humid and shaded localities.

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(b) The resemblances between algae and bryophytes are given below:
(i) Algae and bryophytes both are autotrophic.
(ii) Algal plant body is a thallus, like many bryophytes (Hepaticeae and Anthocerotae).
(iii) In both, the reserve food material is generally starch.
(iv) Both lack vascular tissues.
(v) Water is essential for fertilization in algae as well as in bryophytes.
So, the correct answer is ‘Thallus-like plant body, lack of vascular tissue, autotrophic nutrition’.

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(a) Bryophytes show two morphologically distinct heteromorphic generations, i.e. gametophytic and sporophytic generations. Gametophytic generation is the dominant phase of the life cycle and in general the term ‘plant body’ is used to represent this phase.

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(c) The sex organs in bryophytes (Riccia, Funaria), are multicellular and jacketed. The jacket of the sterile cell around the sperm and egg is an adaptation to a life on land. The male reproductive organs are antheridia and the female reproductive organs are archegonia.

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(a) The sex organs in bryophytes (Riccia, Funaria), are multicellular and jacketed. The jacket of the sterile cell around the sperm and egg is an adaptation to a life on land. The male reproductive organs are antheridia and the female reproductive organs are archegonia.

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(d) In bryophytes, the zygote develops into a multicellular, undifferentiated structure called the embryo. The embryo develops within the venter of the archegonium. By further segmentation and differentiation, it finally develops into a full fledged sporophyte called sporogonium.

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(a) The sex organs in bryophytes are multicellular and jacketed. The embryo develops within the venter of archegonium and not in the water.

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(c) Bryophytes are known as amphibians of the plant kingdom. The main plant body is a haploid that produces gametes and is known as a gametophyte.

After the fertilisation zygote is formed which produces a multicellular body called a sporophyte, which is not free-living but attached to the photosynthetic gametophyte and derives nourishment from it.

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(a) in bryophytes, the sporophyte is parasitic (partially or wholly) on the gametophyte as it is organically attached and is nutritionally dependent upon the gametophyte.

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(d) Peat forms when plant material does not fully decompose in acidic and anaerobic conditions. Sphagnum moss forms peat, for this reason, Sphagnum is also called peat moss. Peat is used as fuel and manure.

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(b) Mosses form a protective covering over the crumbling soil of cliffs and prevent the rushing rainwater from cutting deeply into the soil. These grow in dense mats so firmly interwined around the soil particles that there can be little erosion, even on a steep hillside.

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(a) Asexual reproduction in liverworts takes place by fragmentation of thalli or by the formation of specialised structures called gemmae.

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(c) Asexual reproduction in liverworts takes place by fragmentation of thalli, or by the formation of specialised structures called gemmae.

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(b) Gemmae are green multicellular asexual buds, which develop in small receptacles called gemma cups located on the thalli. Gemmae become detached from parent body and germinate to form new individuals.

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(b) In Marchantia, the plant body consists of a dorsiventrally flattened, prostrate, and dichotomously branched thallus. The thalli are conspicuous, the apex of each thallus is notched. Along the midrib are present characteristic, prominent goblet or cup-shaped structures, the gemma cups, with smooth, dentate, or frilled margins. These cups enclose asexual reproductive bodies called gemma.

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(a) Funaria and Polytrichum are mosses while Riccia and Marchantia are liverworts.

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(a) Funaria exhibits gametophytic ( \(n\) ) as well as sporophytic \((2 n)\) generation in its life cycle. The gametophytic (haploid) generation is represented by a short-lived protonema that produces spermatozoids in antheridium of male shoot and egg in archegonium of the female shoot.

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(d) Sporophyte of Funaria has embedded foot, an elongated curved seta, and a terminal pyriform capsule. Sporophyte is nutritionally dependent on gametophyte.

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(d) Riccia is a liverwort (Hepaticae).

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(a) Fertilisation of Funaria occurs in water. The antherozoids are released into the water where they swim and reach archegonium, An antherozoid fuses with the egg to produce the zygote. thus, an external layer of water is essential for the swimming of male gametes to the archegonia.

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(a) Sperm of mosses is biflagellated, i.e., it has two flagella that aid in propulsion. Since sperm must swim to the archegonium, fertilisation cannot occur without water.

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(c) Sperm of mosses is biflagellated, i.e., it has two flagella that aid in propulsion. Since sperm must swim to the archegonium, fertilisation cannot occur without water.

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(d) Funaria has a radial symmetry with a once branched axis or stem, a number of spirally arranged leaves, and branched colourless multicellular rhizoids. The axis is aerial, erect, slender and monopodially branched.

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(d) Main plant body is gametophytic in bryophytes and sporophytic in pteridophytes.

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(a) Pteridophyta includes primitive vascular plants. The adult plant body in these plants is a sporophyte. It shows differentiation into true roots, stem, and leaves. The stem is mostly herbaceous.

The life cycle includes an alternation of generation of a diploid prophetic generation with a haploid gametophytic generation. Sporophyte generation is dominant.
So, the correct answer is ” (A) – sporophyte, (B) – differentiated “.

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(c) Plants given in the figure are A – Selaginella and B – Salvinia.

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(a) In Equisetum, plant body is differentiated into stem, leaves, and roots. Adventitious roots develop in whorls over the nodes of rhizome. Aerial branches develop terminal strobili. In Earvense, there are two types of aerial branches, green sterile, and brown fertile. Terminal strobili occur only on fertile branches.

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(c) In pteridophytes, spore is a haploid structure, which develops after meiosis of spore mother cell. On germination, it gives rise to a green haploid prothallus (gametophyte) which is monoecious, i.e., has both antheridia (male sex organs) and archegonia (female sex organs).

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(d) The spread of living pteridophytes is limited and is restricted to narrow geographical region because gametophytic growth needs cool, damp, and shady places and there is a requirement of water for fertilisation. So, the correct answer is (d).

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(b) The free-living, multicellular, and photosynthetic gametophytes of pteridophytes are called as the prothallus.
Pteridophytes show alternation of generations. The dominant sporophyte produces spores through meiosis. The gametophyte generation forms gametes by mitosis. The spores are produced by the sporangia in the spore mother cells. These spores germinate and give rise to gametophytes.

The gametophytes (prothallus) produces the male sex organs called antheridia and female sex organs called archegonia.
So the correct option is (b)

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(c) Heterospory is the production of spores of two different sizes and of two different developmental patterns -smaller male or microspores and larger female or megaspores. Heterospory is the most important evolutionary development in vascular plants because it has ultimately led to seed development, e.g., Selaginella, Salvinia, Azolla, etc. So the correct option is c.

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(d) Genera like Selaginella and Salvinia which produce two kinds of spores, are known as heterosporous. The megaspores and microspores germinate and give rise to female and male gametophytes, respectively. The female gametophytes in these plants are retained on the parent sporophytes for variable periods. The development of the zygotes into young embryos take place within the female gametophytes. This event Is the precursor to the seed habit which is considered as an important step in evolution. Hence the correct option is d.

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(c) Pteridophyta is divided into 4 classes:
(A) Psilopsida – Psilotum
(B) Lycopsida – Selaginella
(C) Sphenopsida – Equisetum
(D) Pteropsida – Dryopteris
So, the correct answer is (c).

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(b) In Dryopteris, the sporophytic plant body is differentiated into roots, rhizomatous stem and leaves. It reproduces by means of spores. Prothallus is present which is heart-shaped, monoecious, and protandrous.
So, the correct answer is ” Dryopteris “.

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(c) Salvinia is an aquatic fern. The plant body consists of a floating stem bearing two rows of large green hairy leaves on the upper surface and highly branched leaf roots on the lower surface.

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(b) Gymnosperms do not bear fruits because they do not have ovary.

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(b) Gymnosperms are those seed plants in which the seeds remain exposed over the surface of the megasporophylls because the latter are not folded to form pistils and thus lack ovary. Flowers are absent and thus fruits are not formed. So, the correct answer is ‘They lack ovaries’.

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(c) Gymnosperms are those seed plants in which the seeds remain exposed over the surface of the megasporophylls because the latter is not folded to form pistils and thus lack ovary. Flowers are absent and thus fruits are not formed. So the correct option is c.

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(a) Living gymnosperms are predominantly middle sized trees (Cycas) to tall trees (Pinus) and shrubs (Ephedra). Rarely they are woody climbers (Gnetum montanum). There are no herbs in gymnosperms.

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(a) A mycorrhiza is a symbiotic association of a fungus with a root system. The mycorrhizal roots of Pinus occur near the soil surface. They are devoid of root hair and root cap.

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(c) The coralloid roots of Cycas are symbiotically associated with nitrogen fixing blue-green algae, Anabaena cycadae and Nostoc punctiforme. In the middle cortex of coralloid roots, a broad blue green zone occurs, which is known as algal zone. Coralloid roots are irregular, negatively geotropic, dichotomously branched coral like roots which do not possess root hair and root caps.

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(d) Pinus and Cedrus have branched stem. The main stem shows monopodial branching. Stem branches are of two types, long and dwarf. The dwarf branches possess 1-5 needle-like foliage leaves which are surrounded at the base by a sheath of scale leaves.
So the correct option is d.

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(d) Conifers have a number of xerophytic characters such as needle-like (e.g., Pinus), scale-like (e.g., Thuja) or small and leathery leaves (e.g., Araucaria), thick cuticle, sclerenchymatous hypodermis and sunken stomata to reduce transpiration. They are, thus, well adapted to tide over the winter period when the soil becomes frozen and availability of water is very little.

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(a) Cedrus is a genus of coniferous trees. They are native to the mountains of the western Himalayas and the Mediterranean region.
Cycas is endemic to India. The plants are dioecious.
Ginkgo also is known as the maidenhair tree. It is native to china.
So, the correct answer is ” (A) – Cycas, (B) – Cedrus, (C) – Ginkgo.

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(a) Heterospory is the condition of producing two types of spores, i.e., megaspores and microspores. Heterospory occurs in all seed bearing plants, i.e., gymnosperms and angiosperms.

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(b) Gymnosperms are heterosporous, i.e., produce two different kinds of spores – the male (microspores) and the female (megaspores). The spores are borne inside the sporangia. The two types of sporangia (microsporangia and megasporangia) are borne on special leaf-like structures, called microsporophylls (= stamens) and megasporophylls (= carpels) respectively. The sporophylls are usually aggregated in the form of compact structures called cones or strobili. The cones are generally unisexual, i.e., the male cones are microsporangiate (pollen cones) and the female cones are megasporangiate (seed cones).

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(c) Pinus is a monoecious plant that carry both male and female cone on the same plant but on different branches. The male cone (staminate / microsporangiate strobilus) bears spirally arranged microsporophylls on the central axis. Each microsporophyll carries two microsporangia on the underside. Option c is correct.

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(d) Production of spores of two different sizes and sexes by the sporophytes of land plants is called as Heterospory. In the evolution of plants, Pteridophyta is intermediate between bryophytes and gymnosperms. All bryophytes are homosporous and all gymnosperms are heterosporous. Microspores and megaspores is a characteristic feature in the life cycle of a few members of Pteridophyta and all spermatophytes.
So the correct option is ‘Pteridophyta, Spermatophyta.’

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(d) Cycas is an archegoniate plant, in which female gametophyte contains archegonia.

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(b) In gymnosperms, the pollen grains and the megaspores are haploid and develop as a result of meiosis in the respective mother cells. The functional megaspore forms the embryo sac. The endosperm is formed prior to fertilisation, hence is haploid.

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(c) In Gymnosperms, the male and female gametophytes do not have an independent free-living existence. They remain within the sporangia, retained on the sporophytes i.e., female gametophyte within megasporangium and male gametophyte within microsporangium.
So, the correct option is c.

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(d) Correct answer is (d) Statements (i), (ii) and (iii) are correct.

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(b) Thuja plicata possesses the wood which is used to obtain certain antibiotics. It is resistant to weather and is widely used for commercial purposes. It also provides an essential oil that is used in perfumery. Agar is obtained from the cell wall of red algae Gelidium and Gracilaria.

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(d) The gymnosperms are comparatively more ancient than the angiosperms in evolutionary terms. Most of the gymnosperms have now become extinct and the group is presently represented by only 900 living species. The living gymnosperms are widely distributed in the cold climates where snow is the source of water. Cycas and Ginkgo are referred to as living fossils because they have not yet changed over the years while its related members or species have become extinct or fossilised. The living fossil represents a living unchanged example of an extinct group or genera etc. So, the correct answer is ‘Both a and b’.

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(a) Gnetum belongs to gymnosperms yet shows similarities with angiosperms on one hand and differences with other groups as cycads and conifers at the same time.
Resemblance with the angiosperms:
(i) In general habit, it is climber as tree-like.
(ii) Leaves are broad, green, and with reticulate venation.
(iii) Archegonia are altogether absent in the female gametophyte.
(iv) Absence of free nuclear divisions in the embryo sac.
(v) Endosperm completes its development after the fertilisation.
(vi) Xylem vessels are present.
These similarities with angiosperms separate it from other groups of gymnosperms, e.g., Cycas and Pinus.

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(b) Megasporophyll bears megasporangia. In seed plants, the female gametophyte is produced inside the megasporangium. Fertilization and embryo formation occur there. In angiosperm, the megasporophyll is rolled to produce a carpel. So, the correct answer is ” carpel “.

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(d) In gymnosperms, pteridophytes, and angiosperms, the sporophytic phase is dominant.

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(b) Pteridophytes are vascular cryptogams. They are the first vascular land plants.

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(a) Smallest angiosperm is Wolffia microscopica, while Rafflesia arnoldii is the parasitic plant with the world’s largest flower.

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(b) Leaves show parallel venation in plant A, a characteristic of monocotyledonae except for a few, and reticulate venation in plant B, a characteristic of dicotyledonae.

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(a) In angiosperms, functional megaspore develops into embryo sac. Embryo sac formation is preceded by meiosis, so all the cells of embryo sac are haploid.

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(c) Double fertilisation is a process unique to flowering plants in which two male gamete nuclei, which have travelled down in the pollen tube separately fuse with different female nuclei in the embryo sac/The first male nucleus fuses with egg cell to form the zygote and the second male nucleus fuses with the two polar nuclei or secondary nucleus to form a triploid nucleus that develops into the endosperm.
So the correct option is c.

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(a)  A – Gametophytic generation (n)
B – Sporophytic generation (2n)
So, the correct answer is (a).

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(a)

(A) Pteris – Pteridophyte
(B) Cedrus – Gymnosperm
(C) Sonchus – Angiosperm
(D) Marchantia – Bryophyte
So, the correct answer is (a).

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(c) During the haplontic life cycle, meiosis in the zygote results in the formation of haploid spores.

Hint

(a) Haplontic life cycle, generally occurs in most algae such as Volvox, Spirogyra, and some species of Chlamydomonas.

Hint

(b) In a diplontic life cycle, the dominant free-living phase is the diploid (2n). The sporophyte is photosynthetic. The gametophytic phase is represented by single to few-celled haploid gametophyte. All seed-bearing plants, i.e., gymnosperms and angiosperms exhibit this type of life cycle.
So the correct option is b.

Hint

(c) Few pteridophytes are heterosporous, i.e, with two types of spores, microspores, and megaspores, e. g., Selaginella, Salvinia, Marsilea.

Plants of Cycas are also heterosporous and invariably dioecious, i.e, male and female reproductive organs occur on separate individuals.

Hint

(b) In bryophytes, a dominant, independent, photosynthetic, thalloid, or erect phase is represented by a haploid gametophyte and it alternates with the shortlived multicellular sporophyte which is totally or partially dependent on the gametophyte for its anchorage and nutrition.
So the correct option is b.

Hint

(a) Following are the correct statements:
(i) Bryophytes show alternation of generation.
(ii) A haploid gametophytic generation and a diploid sporophytic generation alternate in the life cycle.
So, the correct answer is (a).

Hint

(c) In pteridophytes, the diploid sporophyte is represented by a dominant, independent, photosynthetic, vascular plant body. It alternates with multicellular, independent but short-lived haploid gametophyte.