RBSE Class 11 Biology Notes Chapter 5 Morphology of Flowering Plants

These comprehensive RBSE Class 11 Biology Notes Chapter 5 Morphology of Flowering Plants will give a brief overview of all the concepts.

RBSE Class 11 Biology Chapter 5 Notes Morphology of Flowering Plants

→ Angiosperms or flowering plants is the most vast group of plants.

→ Angiosperms show wide diversity in shape, size, structure, method of nutrition, life cycle, nature and habitat.

→ Angiosperms are divided into two groups: Monocotyledons and Dicotyledons.

→ Each plant has two main system

1. root system and
2. shoot system.

→ Generally two types of roots are present in plants - Tap roots and Adventitious roots.

→ Generally tap roots are found in dicotyledons and adventitious roots in monocotyledons.

→ Root system comprises of main root, primary and secondary roots, root hairs and root cap.

→ Shoot system comprises of aerial branches, stem, leaves and inflorescence.

 

→ Shoot system differs root system due to presence of nodes and internodes, axillary buds, scaly leaves, multicellular hairs and being positively phototropic.

→ Roots are positively geotropic.

→ Various modifications are found in stem and root e.g., storage, reproduction, nutrition and other ecological adaptations. 

→ Root is divided into three distinct parts - meristematic activity part covered by root cap, zone of elongation which elongates the root in length and the zone of maturation covered with root hairs.

→ Carrot, radish, turnip are tap roots which gets modified as swollen structures for the storage of food.

→ Prop roots of banyan and stilt roots of sugarcane are modified to give support to the plant.

→ Some roots of Rhizophora are seen above the ground for breathing. These are called pnematophores. Potato, ginger, turmeric, zaminkand etc., are underground stem which gets modified for the storage of food.

→ Stem of some weak plants or some of their parts gets modified into tendril, thorn etc, which help plants in standing straight or climbing.

→ Stems of some xerophytic plants get modified and becomes succulent or phylloclade to prevent water loss.

→ Leaves are thin flat structures attached to stem.

→ Leaves perform the function of photosynthesis, transpiration and respiration.

→ Leaves also get modified for storage, climbing and reproduction.

→ Leaves are of two types - simple and compound leaves.

→ Venation in monocotyledons is parallel and in dicotyledons is reticulate.

→ Arrangement of flowers on floral axis is called inflorescence.

→ Flower is a modified shoot.

→ Male and female reproductive organs are found on flower. Each flower has four or five or sometimes lesser whorls.

→ Whorls are arranged in following order- calyx, corolla, androecium and gynoecium.

→ When calyx and corolla cannot be differentiated, it is called perianth.

→ Androceium is male reproductive part of the flower consisting of several stamens. Each stamen has three parts - filament, connective and anther.

→  Pollen grains are formed in anther.

→ Gynoecium is female reproductive part formed of one or more carpel. Each pistil has three parts - ovary, style and stigma.

→ Arrangement of ovule in ovary is called placentation. The place where ovule is attached to ovary is called placenta.

→ Fruit is the primary characteristic of flowering plants. It is a mature ovary which develops after fertilization.

→ Process of developing fruit without fertilization is called parthenocarpy.

→ Seeds are derived from ovule after fertilization.

→ Endosperm is food storage tissue which is developed due to triple fusion (one male nuclei and two secondary nuclei) in the process of double fertilization.

→ If only cotyledon is present in the seed, it is called monocotyledon and if two cotyledon is present then it is dicotyledon.

→ Floral characteristics are represented briefly by floral diagram and floral formula.

→ Monocotyledons plants are considered more advance than dicotyledons plants.

→ Achene: hard, dry, single seeded indehiscent fruit e.g., Clematis.

→ Actinomorphic: When a flower can be divided into two equal radial halves in many radial planes passing through the centre.

→ Albumen: a nutritious protein layer present around embryo in some seeds.

→ Androecium: group of stamens.

→ Anther: Part of stamen in which pollen grains are found.

→ Apocarpous: When carpels are not attached to each other in ovary.

→ Aril: extended part of funicle which arises from placenta.

→ Axil: The angle between axis and organ attached to that axis. Like - leaves.

→ Axillary: developed in axis.

→ Berry: fully succulent fruits in which seeds are embedded, e.g. Grapes.

→ Bipin nate: when both the primary and secondary divisions in leaves are pinnate.

→ Bracteole: Bract of single flower in inflorescence.

→ Bracts: modified leaves between leaves and calyx sometimes form involucres and coloured bracts.

→ Bulb: modified underground stem on which axillary buds and modified leaves are present.

→ Calyx: Outermost whorl of the flower.

→ Capsule: dry, dehiscent fruit formed from one or more carpels.

→ Caryopsis: a fruit of grass family in which seed coat is attached to epicarp. e.g., wheat, maize.

→ Catkin: hanging spike of weak monosexual flower. e.g., mulberry.

→ Cauline: related to stem

→ Connective: part of stamen connecting anther.

→ Corm: fleshy underground part of stem.

→ Cotyledon: lobes of seed or primary leaf, leaves of seed.

→ Cremocarp: A dry fruit formed from two one seeded carpels. The carpels remain separate and form indehiscent mericarp. e.g. Cumin

→ Culm: hollow stem, e.g., grass and bamboo.

→ Decompound: Divided several times.

→ Dioecious: unisexual plants on which male and female flowers are borne on separate plants.

→ Drupe: succulent fruit with hard endocarp in which one seed is present e.g., Mango.

→ Endosperm: albuminous part of seed generally limited to embryo sac (developed from triple fusion)

→ Epicalyx: encircle of bract resembling calyx,

→ Epigynous: above ovary,

→ Epipetalous: above petals or corolla,

→ Follicle: unilocular fruit which ruptures only from lower suture,

→ Fruit: a ripened ovary.

→ Funicle: stalk which connects seed or ovule to placenta of ovary.

→ Gamopetalous: where petals are united,

→ Hilum: mark on seed where stalk is attached to funicle or placenta

→ Hypogynous: below gynoecium.

→ Inflorescence: arrangement of flowers on ah axis.

→ Internode: part between two nodes on stem.

→ Involucre: structure formed due to union of several bracts which encircles several flowers

→ Legume: elongated fruit of leguminaceae family which is derived from unilocular ovary and opens from bottom.

→ Lomentum: a pod in which pericarp constricts to divide fruit into single seeded mericarps. e.g., Tamarind, groundnut etc.

→ Monodelphous: when all the filaments of stamens are united into one bunch or one bundle to form a pollen tube on which anthers are attached, e g., Hibiscus (China Rose).

→ Monoecious: when male and female flowers are separate but found on single plant e.g., Maize.

→ Node: part of stem from where leaves arise,

→ Nut: hard, indehiscent, single seeded fruit.

→ Offset: lateral thick stem used for reproduction.

→ Ovhry: lower swollen part of a locule where ovules are formed.

→ Ovule: macrosporangium of angiosperms. Structures which forms fruit after fertilization.

→ Palmate: lobed in the form of hand.

→ Papilionaceous: butterfly shaped flowers of Fabaceae family.

→ Parietal: attached to wall,

→ Pedical: stalk of a flower

→ Peduncle: stalk of inflorescence,

→ Perfect: used for bisexual flower

→ Perianth: when calyx and corolla are indiffrentiated, it is perianth. It’s one part is called tepal. In short, calyx and corolla are parts of perianth,

→ Petiole: stalk of leaf.

→ Phyllode: Petiole modified to leaf, 

→ Pistil: group of carpels.

→ Placenta: place of ovary where ovules are present,

→ Polypetalous: when petals are separated (not fused).

→ Pulvinous: swollen petiole.

→ Radicle: part of embryo of seed which develops into root, part forming primary root.

→ Receptacle: axis of flower on which all the parts of flower are attached, also known as thalamus or torus,

→ Replum: false septum found in fruits of family Cruciferae (Brassicaceae) which divides ovary into two locules.

→ Rhizome: horizontally growing modified underground stem, e.g., Ginger.

→ Samara: indehiscent winged fruit

→ Scape: leafless floral axis which originates directly from root.

→ Sepaloid: like sepals.

→ Sessile: without petiole.

→ Siliqua: pod like fruit of Brassicaceae where seeds are attached to replum. Initially, the ovary is unicarpellary, but it becomes bicarpellary due to formation of false replum,

→ Spadix: spike with muscular axis,

→ Spathe: large colourful bract of spadix which encircles inflorescence.

→ Staminode: sterile stamens.

→ Standard: most important part of corolla present in papilionaceous flower.,

→ Stipule: an structure present at the base of leaf,

→ Tendril: thread like leaf or stem modification assisting the plant to climb, 

→ Testa: outer integument of seed, 

→ Zygomorphic: when flower can be divided into two similar halves only in one particular vertical plane. e.g., pea, gulmohur, bean, Cassia.