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Flower: Besides the essential whorls of microsporophylls (androecium) and megasporophylls (gynoecium), there are accessory whorls namely, calyx (sepals) and corolla (petals) arranged together to form flowers.

Ginkgo biloba is called as living fossil, because this plant is found in living as well as fossil form and the number of fossil forms is much more than the living forms.

(c) Sporophyte

1. Forms of green algae: 

Unicellular motile: e.g. Chlamydomonas Unicellular nonmotile: E.g. Chlorella Colonial forms: e.g. Volvox Filamentous branched: e.g. Cladophora, Chara Filamentous unbranched: e.g. Ulothrix, Spirogyra 

2. Forms of red algae: 

The red thalli of most of the red algae are multicellular, macroscopic, e.g. Gracilaria, Gelidium, Porphyra, Polysiphonia, etc. . 

3. Forms of brown algae: 

Simple, branched and filamentous: Sargassum, Fucus, Ectocarpus Profusely branched: Laminaria, Dictyota, Kelps (Seaweed) 

4. Forms of blue-green algae: 

Unicellular, colonial or filamentous, freshwater or marine water or terrestrial algae.

(a) Many species of algae are used as food. For e.g. Chlorella (rich in cell proteins hence used as food supplement, even by space travelers), Sargassum, Laminaria, Porphyra, etc. 

(b) Alginic acid is produced commercially from Kelps. 

(c) Hydrocolloids like algin and carrageen are obtained from brown algae and red algae respectively. 

(d) ‘Agar’ which is used as solidifying agent in tissue culture is obtained from red algae like Gelidium and Gracilaria. 

(e) Brown algae like sea weeds are used a fodder for sheep, goat, etc.

(f) Role of algae in environment.

(a) Being photosynthetic, algae help in increasing the level of dissolved oxygen in their immediate environment. 

(b) Algae are primary producers of energy rich compounds which forms the basis of food cycles in aquatic animals.

Members of Bryophyta are mostly terrestrial plants which depend on water for fertilization and completion of their life cycle. Hence, they are called ‘amphibians of Plant Kingdom’.

1. The plants which do not bear flowers, fruits and seeds, but have true roots, stem and leaves belong to division Pteridophyta. 

2. These plants are cryptogams as they do not produce seeds and flowers.

3. They have primitive conducting system.

Funaria belongs to division Bryophyta. It is a terrestrial plant but requires water for fertilization and completion of its life cycle. Hence, it is called as an amphibious plant.

Characters Dicotyledonae Monocotyledonae 

1. Type of roots Tap roots Fibrous roots 

2. V enation in the leaves Reticulate venation Parallel venation 

3. Symmetry of flower Tetramerous or Pentamerous symmetry Trimerous symmetry

1. Maize plant belongs to class monocotyledonae. 

2. In monocotyledonous plants, vascular bundles are closed type. 

3. Thus, cambium is absent between xylem and phloem, due to which secondary growth does not occur in these plants. 

4. Increase in girth of a stem occurs by secondary growth. Thus, girth of a maize plant does not increase over a period of time.

(d) Double fertilization

(a) Sequoia sempervirens

Characteristics of Phaeophyceae (Brown algae): 

1. These algae are mostly marine, rarely fresh water. 

2. Plant body is simple branched, filamentous (e.g. Ectocarpus) or profusely branched (e.g. Petalonia). 

3. Cell wall has cellulose, fucans and algin. 

4. Photosynthetic pigments like chlorophyll-a, chlorophyll-c and fucoxanthin are present. 

5. Mannitol, laminarin are stored food materials. Body is usually differentiated into holdfast, stalk called stipe and leaf-like photosynthetic organ called frond.

6. Many species of marine algae are used as food. e.g. Laminaria, Sargassum. 

7. Some species are used for the production of hydrocolloids (water holding substances), e.g. Ectocarpus, Fucus, etc.

1. Phanerogams are seed producing plants. These plants produce special reproductive structures that are visible. 

2. Cryptogams are spore producing plants. These plants do not produce seed and flowers. They reproduce sexually by gametes, however their sex organs are concealed.

1. Fern belongs to sub-kingdom Cryptogamae. 

2. Cryptogams produce spores but do not produce seeds.

3. Also, in cryptogams the sex organs are concealed. 

4. Phanerogams are seed producing plants and their sex organs are visible. 

5. Hence, fern is a vascular plant. Yet it is not considered a Phanerogams.

The given figure is of Gracillaria. It belongs to class Rhodophyceae (Red algae). 

Characteristics of Rhodophyceae: 

1. Habitat: These are found in marine as well as fresh water on the surface, deep sea and brackish water. 

2. Plant body: Plant body is thalloid. 

3. Photosynthetic pigments: Cells contain chlorophyll-a, chlorophylld and phycoerythrin. 

4. Cell wall: Cell wall is made up of cellulose and pectin glued with other carbohydrates. 

5. Stored food: Stored food is in the form of Floridean starch.

Phanerogams are seed producing plants. These plants produce special reproductive structures that are visible.

Red algae like Gelidium and Gracilaria are used to obtain agar-agar which is used as solidifying agent in tissue culture medium.

Rhizoids are unicellular in liverworts while they are multicellular in mosses.

1. c – 1 

2. d – 2 

3. a – 4 

4. b – 3

Cryptogams are spore producing plants. These plants do not produce seed and flowers. They reproduce sexually by gametes, however their sex organs are concealed.

Red algae like Gelidium and Gracilaria are used to obtain agar-agar which is used as solidifying agent in tissue culture medium.

1. (B) Marchantia

2. (C) Pteridophytes

3. (D) Lycopodium

4. (B) Selaginella

5. (C) non-vascular

6. (B) Pinus

1. Gametophytic phase of the life cycle of Mosses (Musci) includes two stages namely; protonema stage and leafy stage. 

2. The protonema is prostrate green, branched and filamentous (it is also called juvenile gametophyte). It bears many buds. 

3. Leafy stage is produced from each bud. 

4. Vegetative reproduction takes place by fragmentation and budding in secondary protonema.

5. The leafy stage has erected, slender stem like (Cauloid) main axis bearing spiral leaf like structures (Phylloid). 

6. It is fixed in soil by multicellular branched rhizoids. 

7. Leafy stage bears sex organs.

Pteridophytes are known as first vascular and true land plants.

X: Oogonium (contains egg) 

Y: Antheridium (contains sperms)

Habitat: Pteridophytes grow in moist and shady places,

e.g. Ferns, Horsetail. Some are aquatic (Azolla, Marsilea), xerophytic (Equisetum) and epiphytic (Lycopodium).

(a) Double fertilization is a characteristic feature of angiosperms. 

(b) In this process one male gamete fuses with egg cell and another male gamete fuses with secondary nucleus, to form an embryo and endosperm respectively.

Economic importance of Bryophytes: 

1. Some mosses provide food for herbivorous mammals, birds, etc.

2. Mosses along with lichens are the first living beings to grow on rocks. They decompose rocks to form soil and make them suitable for growth of higher plants. 

3. Dense layers of mosses help in prevention of soil erosion, thus act as soil binders.

1. Pteridophytes are known as first vascular and true land plants. 

2. Habitat: Pteridophytes grow in moist and shady places, e.g. Ferns, Horsetail. Some are aquatic (Azolla, Marsilea), xerophytic (Equisetum) and epiphytic (Lycopodium). 

3. Plant body: It is differentiated into root, stem and leaves. 

4. Primary root: The primary root is short lived and is soon replaced by adventitious roots. 

5. Stem: The stem may be aerial or underground. 

6. Leaves: This group contains plants with pinnate (feather – like) leaves. Leaves may be scaly (e.g. Equisetum), simple and sessile (e.g. Lycopodium), small (microphylls e.g. Selaginella) or large (macrophylls) and pinnately compound (e.g. Nephrolepis l Ferns). 

7. Vascular tissues: In these members xylem consists of only tracheids and phloem consists of only sieve cells. 

8. Secondary growth: Secondary growth is not seen in pteridophytes due to absence of cambium. 

9. Alternation of generations: Pteriodphytes show heteromorphic alternation of generations in which the sporophyte is diploid, dominant, autotrophic and independent. Gametophyte is haploid multicellular, generally autotrophic and short lived.

Habitat: Pteridophytes grow in moist and shady places, e.g. Ferns, Horsetail. Some are aquatic (Azolla, Marsilea), xerophytic (Equisetum) and epiphytic (Lycopodium).

1. The given figure indicates diplontic life cycle. 

2. Here, mitotic division occurs only in diploid cells. 

3. Gametes formed through meiosis are haploid in nature. 

4. The diploid zygote formed after fertilization divides mitotically. 

5. In this process, production of multicellular diploid organism or the production of many diploid single cells takes place. 

6. Animals show diplontic life cycle. 

[Note: Diplontic type of life cycle is commonly observed in animals and all seed-bearing plants i.e. gymnosperms and angiosperms.]

Two classes of Angiosperms are Dicotyledonae and Monocotyledonae. 

а. Dicotyledonae: 

1. These plants have two cotyledons in their embryo. 

2. They have a tap root system and the stem is branched.

3. Leaves show reticulate venation. 

4. Flowers show tetramerous or pentamerous symmetry.

5. Vascular bundles are conjoint, collateral and open type.

6. Cambium is present between xylem and phloem for secondary growth. 

7. In dicots, secondary growth is commonly found. 

e. g. Helianthus annuus (Sunflower) 

b. Monocotyledonae: 

1. These plants have single cotyledon in their embryo. 

2. They have adventitious root system and stem is rarely branched.

3. Leaves generally have sheathing leaf base and parallel venation. 

4. Flowers show trimerous symmetry. 

5. The vascular bundles are conjoint, collateral and closed type. 

6. Cambium is absent between xylem and phloem. 

7. In Monocots, except few plants secondary growth is absent, 

e.g. Zea mays (Maize)

(a) In dicots, vascular bundles are conjoint, collateral and open type. Cambium is present between xylem and phloem for secondary growth. 

(b) Whereas in monocots, vascular bundles are conjoint, collateral and closed type. Thus, due to absence of cambium, secondary growth does not occur in majority of monocots.

1. Cycas is grown as an ornamental plant. 

2. Pinus is used as source of pine wood, turpentine oil and pine resin.

Vinaya’s teacher must have told her that the green coloured covering floating on the surface of pond water can be green algae like Spirogyra, Chlorella, Chlamydomonas, etc.

1. Coralloid roots of Cycas: 

Coralloid roots of Cycas show association with blue green algae for nitrogen fixation.

Coralloid roots are coral-like, dichotomously branched and fleshy. They grow upward toward the surface of the soil. These roots arise from the lateral branches of normal roots. 

2. Scale leaf of Cycas: 

In Cycas leaves are dimorphic i.e. foliage leaves and scale leaves. Scale leaves are minute, membranous and brown. These are non- photosynthetic and provide protection to the stem apex. 

3. Megasporophyll of Cycas: 

Megasporophylls are usually arranged in compact structures called female cones or female strobili. Megasporophyll contains megasporangia (ovule) which produce megaspores.

1. When we observe garden plants like Cycas, Thuja, Pinus, Sunflower, Canna, following similarities can be observed: Plant body is divided into root, stem and leaves. 

2. When we observe garden plants like Cycas, Thuja, Pinus, Sunflower, Canna, following dissimilarities can be observed: 

(a) In Cycas, Thuja and Pinus seeds are not enclosed within a fruit, whereas in Sunflower and Canna seeds are enclosed within a fruit. 

(b) Plants like Cycas, Thuja, Pinus show cones bearing microsporophylls and megasporophylls, whereas sunflower and Canna plant bear flowers. 

(c) In Cycas, Thuja and Pinus green, simple needle like or pinnately compound foliage leaves and brown, membranous scaly leaves can be observed, whereas in Sunflower, Canna green foliage leaves can be observed.