Plant Kingdom

The gymnosperms are plants in which the ovules are not enclosed by any ovary wall and remain exposed, both before and after fertilisation.

Pinus is a gymnosperm.

Funaria is a moss.

Selaginella is a pteridophyte.

In gymnosperm, the male and female gametophytes do not have an independent free-living existence. They remain within sporangia, retained on the sporophyte.

In gymnosperms the ovules are not enclosed by any ovary wall and remain exposed, both before and after fertilisation. The seeds that develop post fertilisation, are not covered, i.e., naked.

Sphenopsida class belongs to pteridophytes.

The gymnosperms (Gymnos : naked, sperma seed) are plants in which the ovules are not enclosed by an ovary wall and remains exposed, both before and after fertilization. The seeds that develop post-fertilization, are not covered, i.e., naked.

Pteridophyte - Salvinia

Bryophyte - Polytrichum

Angiosperm - Salvia

Gymnosperm - Ginkgo

Gemmae are green, multicellular, asexual buds which develop in small receptacles called gemma cups and help in asexual reproduction in bryophytes.

In a pteridophytes life cycle, the correct sequence of stages will be given as follows:

B $\rightarrow$ Meiosis in spore mother cells

A $\rightarrow$ Prothallus stage

D $\rightarrow$ Formation of archegonia and antheridia in gametophyte

$\mathrm{E} \rightarrow$ Transfer of antherozoids to the archegonia in presence of water

C $\rightarrow$ Fertilisation will occur

So, the correct sequence is $\mathrm{B} \rightarrow \mathrm{A} \rightarrow \mathrm{D} \rightarrow \mathrm{E} \rightarrow \mathrm{C}$

The correct sequence of events in the life cycle of bryophytes is

$\bullet$ Attachment of gametophyte to substratum.

$\bullet$ Release of antherozoids into water.

$\bullet$ Fusion of antherozoid with egg.

$\bullet$ Formation of sporophyte.

$\bullet$ Reduction division to produce haploid spores.

Gymnosperms are a group of seed-producing plants that include conifers, cycads, Ginkgo, and gnetophytes. Unlike angiosperms (flowering plants), gymnosperms do not have flowers and their seeds are not enclosed in an ovary. Let's look at each of the options provided to determine which one is not found in gymnosperms:

Option A: Sieve cells

Sieve cells are a type of cell found in the phloem tissue of vascular plants. Gymnosperms have sieve cells for their nutrient transport.

Option B: Albuminous cells

Albuminous cells, also known as Strasburger cells, are associated with sieve cells in gymnosperms. These cells play a role similar to companion cells in angiosperms by assisting in the function of sieve cells.

Option C: Tracheids

Tracheids are elongated cells in the xylem of vascular plants that serve in the transport of water and mineral salts. Gymnosperms rely on tracheids for their water conduction and structural support.

Option D: Vessels

Vessels are tube-like structures in the xylem that are responsible for the efficient transport of water. They are characteristic of angiosperms. Gymnosperms primarily use tracheids for water transport rather than vessels.

Based on the information above, the correct answer is:

Option D: Vessels

To identify the incorrect pair, we need to understand the classification of different plant types under the division Pteridophyta, which include four classes:

1. Psilopsida: This class includes primitive vascular plants that do not have true leaves or roots. They have simpler structures. A common example is Psilotum.

2. Lycopsida: These are characterized by microphyllous leaves and strobili (cones). An example is Selaginella.

3. Sphenopsida: This class includes plants that have jointed stems and small leaves usually arranged in whorls. An example is Equisetum, rather than Adiantum.

4. Pteropsida: These are the most evolved among pteridophytes and include ferns with large leaves (megaphylls). Examples include Dryopteris, Pteridium, etc.

Now let's analyze each option:

Option A: Sphenopsida – Adiantum

This pair is incorrect. Sphenopsida includes plants like Equisetum, not Adiantum. Adiantum belongs to the class Pteropsida.

Option B: Pteropsida – Dryopteris

This pair is correct. Dryopteris is a type of fern and belongs to the class Pteropsida.

Option C: Psilopsida – Psilotum

This pair is correct. Psilotum is a representative of the class Psilopsida.

Option D: Lycopsida – Selaginella

This pair is correct. Selaginella is a member of the class Lycopsida.

Thus, the incorrect pair is:

Option A: Sphenopsida – Adiantum

Let us carefully analyze each of the options given to determine the correct match:

Option A: Gymnosperms : Cedrus, Pinus, Sequoia

Explanation: Gymnosperms are a group of seed-producing plants that include conifers, cycads, Ginkgo, and gnetophytes. Both Cedrus (cedars), Pinus (pines), and Sequoia (redwoods) belong to the gymnosperms. Thus, the match is correct.

Option B: Angiosperms : Wolffia, Eucalyptus, Sequoia

Explanation: Angiosperms are flowering plants. While Wolffia (smallest flowering plant) and Eucalyptus are angiosperms, Sequoia is a gymnosperm. Hence, this match is incorrect.

Option C: Bryophytes : Polytrichum, Polysiphonia, Sphagnum

Explanation: Bryophytes are non-vascular plants like mosses and liverworts. While Polytrichum and Sphagnum are indeed bryophytes, Polysiphonia is a red algae (Rhodophyta) and not a bryophyte. Thus, this match is incorrect.

Option D: Pteridophytes : Equisetum, Ginkgo, Adiantum

Explanation: Pteridophytes are a group of vascular plants that reproduce via spores. Equisetum (horsetails) and Adiantum (maidenhair ferns) are pteridophytes, but Ginkgo is a gymnosperm. Hence, this match is incorrect.

Therefore, the correct match is:

Option A: Gymnosperms : Cedrus, Pinus, Sequoia

Let's analyze each statement:

Statement A: Asexual reproduction occurs usually by biflagellate zoospores. - This statement is true for Phaeophyceae (brown algae). Asexual reproduction in these algae generally involves the release of biflagellate zoospores that swim away and eventually settle and grow into new individuals.

Statement B: Sexual reproduction is by oogamous method only. - This statement is partially true. While sexual reproduction in Phaeophyceae often is oogamous (involving a large non-motile egg and a smaller motile sperm), there are instances where isogamy (both gametes are motile and similar in size) occurs, though it is less common. Thus, the statement might be misleading as it implies that oogamy is the only method of sexual reproduction.

Statement C: Stored food is in the form of carbohydrates which is either mannitol or laminarin. - This statement is correct. In brown algae, the primary carbohydrates stored are mannitol and laminarin. These serve as crucial energy storage compounds.

Statement D: The major pigments found are chlorophyll a, c and carotenoids and xanthophyll. - This statement is true. The brown algae have chlorophyll a, c, various carotenoids, and xanthophylls like fucoxanthin which give them their distinctive brown color.

Statement E: Vegetative cells have a cellulosic wall, usually covered on the outside by a gelatinous coating of algin. - This statement is true. Brown algae have cell walls made of cellulose and are often covered by a layer of alginates, which can form a gelatinous coating. This helps in providing structural support and protection against dessication and mechanical damage.

Given these analyses:

• A, C, D, and E are true.
• B is not exclusively true as it suggests that oogamy is the only form of sexual reproduction.

Thus, the correct option is:

Option C: A, C, D and E only

The question asks for a match between classes of Pteridophytes (List I) and their examples (List II).

Pteridophytes are a group of plants that include ferns and their allies. These plants reproduce via spores rather than seeds. The Pteridophytes are divided into various classes including Pteropsida, Lycopsida, Psilopsida, and Sphenopsida.

Here's the correct match :

1. Pteropsida (A) - Adiantum (III). Adiantum (maidenhair fern) is an example of a fern, which falls under the class Pteropsida.
2. Lycopsida (B) - Selaginella (IV). Selaginella is an example of clubmoss, which falls under the class Lycopsida.
3. Psilopsida (C) - Psilotum (I). Psilotum is an example of whisk ferns, which falls under the class Psilopsida.
4. Sphenopsida (D) - Equisetum (II). Equisetum is an example of horsetail, which falls under the class Sphenopsida.

So, the correct answer is Option D :

(A)-(III), (B)-(IV), (C)-(I), (D)-(II)

Option B : Phaeophyceae and Rhodophyceae

Explanation :

Phaeophyceae, commonly known as brown algae, owe their characteristic brown or olive color to the pigment fucoxanthin. This is a type of xanthophyll, a class of oxygen-containing carotenoid pigments, that masks the green color of chlorophyll.

Rhodophyceae, commonly known as red algae, are predominantly colored by the pigment r-phycoerythrin. This pigment reflects red light and absorbs blue light, which allows red algae to live at greater depths than many other types of algae because blue light penetrates water deeper than light of longer wavelengths.

These pigments, along with chlorophylls, not only give these algae their distinctive colors but also allow them to perform photosynthesis by capturing light energy at specific wavelengths.

(A) Statement is absolutely correct that “all pteridophytes exhibit haplo-diplontic pattern” - Yes, that's correct. In pteridophytes, which includes ferns and their allies, the haplo-diplontic life cycle is observed. There is an alternation of generations between a haploid (n) gametophyte stage and a diploid (2n) sporophyte stage. Both stages are free-living and independent.

(B) Seed-bearing plants are gymnosperms and angiosperms and both of them follow diplontic life cycle pattern. In these groups, the sporophyte generation is dominant, and the gametophyte generation is reduced and dependent on the sporophyte. The life cycle is thus said to be diplontic.

(C) Most algal genera are haplontic - This is generally true. The majority of algae, especially the green algae (Chlorophyta) and red algae (Rhodophyta), exhibit a haplontic life cycle where the dominant, photosynthetic phase is the haploid gametophyte.

(D) Most bryophytes have haplo-diplontic life cycle pattern - Bryophytes, including mosses, liverworts, and hornworts, do have a haplo-diplontic life cycle. In this cycle, there is an alternation of generations between a haploid (n) gametophyte stage and a diploid (2n) sporophyte stage. However, in bryophytes, the gametophyte stage is dominant and long-lived while the sporophyte is dependent on the gametophyte and short-lived.

Selaginella and Salvinia are heterosporous pteridophytes. They produces two different kind of spores. Psilotum, Lycopodium and Equisetum are homosporous pteridophytes.

Chlamydomonas is a unicellular alga. Cycas is a gymnosperm. Selaginella is a heterosporous pteridophyte and Sphagnum is a moss.

Alga shown in the diagram is Chara. It is a member of Chlorophyceae. Food is stored in the form of starch.

Chara is monecious plant showing oogonium and antheridium on the same plant body.

Hydrocolloids are water holding substances for e.g. carrageen obtained from red algae (Rhodophyceae).

Ulothrix is a member of Chlorophyceae (green algae), with reserve food material, starch. Mannitol is stored food material of Phaeophyceae (brown algae).

Spirogyra is an alga. It shows haplontic life-cycle.

Fern is pteridophyte. The dominant phase of life-cycle is diploid sporophyte. Its gametophyte is called prothallus.

Funaria is a bryophyte. Its gametophyte is a leafy stage.

Cycas is a gymnosperm. The main plant body in gymnosperm is sporophyte. They have highly reduced gametophyte stage.

Lycopodium, Equisetum, Psilotum are homosporous. Those plants which produce only one kind of spores are called homosporous. Salvinia, Selaginella are examples of heterosporous plants that produce two kinds of spores; macrospore and microspore.

Both assertion and reason are false. Most of the pteridophytes are homosporous meaning they produce similar spores. Selaginella and Salvinia are exception. They produce two kinds of spores (microspores and megaspores). In Selaginella plant, there is seen the seed habit, so it is marked as precursor of seed habit evolution in plants.

Assertion : Heterospory and retention of female gametophyte are responsible for the origin of seed habit in Selaginella.

Reason : Psilotum is a living fossil.

Explanation :

Both the assertion and reason are true, but the reason does not correctly explain the assertion.

Heterospory and the retention of the female gametophyte are indeed responsible for the origin of the seed habit in Selaginella, a pteridophyte. Heterospory refers to the production of two types of spores—microspores and megaspores—by the same plant.

Psilotum, also a pteridophytic plant, is known for its primitive pteridophytic characteristics, which is why it is referred to as a living fossil. However, this does not explain the seed habit in Selaginella.

Summary of Key Points :

Heterospory : Production of two types of spores (microspores and megaspores) by the same plant.

Seed Habit in Selaginella : Originated due to heterospory and retention of the female gametophyte.

Psilotum : Known for its primitive characteristics and is referred to as a living fossil.

This clarification ensures that the linkage between the assertion and reason is correctly understood.