Write a note on economic importance of algae and gymnosperm

Solution • Importance of gymnosperms : (i) For decorations : Some gymnospermia plants which belong to other regions. They are reared in Indian gardens for decoration. Like cycas reviemleta, Cupresses, Sempervivums, Cupresses Funibares, Thuja and some species of orekeria etc. (ii) As a food Article : Some gymnospermc plants produce some products they are used as a food in direct or indirect ways. e.g. from Cycas Sarsinalis.s stem and seed starch is obtained. It is called Sago. • The seeds of Pinus (Chilgoza) are very nutritious and edible. • Zingo (Gingo) seeds are very nutritive and used as food in China and Japan. (iii) Wood : Some gymnospermic plants are well known for their precious timber. • Abies, Cedrus, Deodare, Pinus give timber. • Seeds of Gnetum and its inflorescence are used as vegetable. (iv) Medicinal uses : Resin obtained from Cycas is used to apply on ulcer. • Seeds of Deodar are used for diseases of lung and kidney, urinary diseases. • Cupresses sampervires produces a necessary oil. It acts as a Vermifuge. • Pinus is used in treatment of (Rokbergi), diseases of stomach and kenorrea. • Ephedra give Ephedrin drug which is useful in problems of Asthma and frachea. (v) Resin and Oils : Produces terpantine and from Turpentine many oils are formed. (vi) Other uses : The wood Pinus is used as fuel. • Cycas riviewlota is used to make wine. • Taxin is obtained from Junoparers Virginian which is used in Tanning of leather. • Canada Balsam is obtained from Abies Balsam.

The ploidy of the following are: (a) Protonemal cell of a moss – Haploid (b) Primary endosperm nucleus in a dicot – Triploid (c) Leaf cell of a moss – Haploid (d) Prothallus of a fern – Haploid (e) Gemma cell in Marchantia – Haploid (f) Meristem cell of a monocot – Diploid (g) Ovum of a liverwort – Haploid (h) Zygote of a fern – Diploid Archegonium is the female sex organ that produces the female gamete or egg. It is present in the life cycles of mosses (bryophytes), pteridophytes, and gymnosperms. Life cycle of a moss. Gametophytic stage is the predominant stage of the moss lifecycle. The Gametophytic stage consists of two stages (i). Protenema stage – this is the first stage which develops directly from a spore. (ii). Leafy stage – this is the second stage which develops from the secondary protonema as a lateral bud. They consist of upright slender axes which bears spirally arranged leaves. Rhizoids are the multicellular structure that attaches the mosses to the soil. This stage bears the sex organs. The male (antheridia) and female (archegonium ) sporangia are formed at the apex of the leafy shoots. Cells within the sporangium of the sporophyte undergo meiosis to produce male and female spores, respectively. These spores divide mitotically to produce multicellular male and female gametophytes. The sperm and eggs are produced mitotically in the antheridia and archegonia, respectively. Sperm are carried to the archegonia in water droplets. After fertilisation, the sporoph...

Algae – increase the level of oxygen in environment. They are the chief producers in aquatic ecosystems Some species ofbrown algae like sargassum, laminaria & Porphyra are used as food. Red algae and brown algae produce hydrocolloids which are water-holding substances. Eg: Gracilaria & gelidium Clorella is used as food supplement by space travelers. Gymnosperm – Produce alkaloids like terpentine from the stem. They are grown as an ornamental plant. Certain species like ephedra are medicinal.