Uses of gymnosperms - class-VIII

Turpentine oil is made from the resin of certain pine trees. It is used as medicine. Don't confuse turpentine oil with gum turpentine, which is the resin. Turpentine oil is applied to the skin for joint pain, muscle pain, nerve pain, and toothaches. So, the correct option is "C" (Most kinds of pine trees).

Chilgoza pine (Pinus gerardiana) is well known for its edible pine nuts, rich in carbohydrates and protein . The seeds are locally called and marketed as "chilgoza".

Sago is a starch extracted from the pith of the stem of the Cycas plant.

Heterospory, seed formation and fertilization are found in gymnosperm. 

Araucaria is commonly known as the Christmas tree or monkey puzzle tree and is widely grown for its ornamental appearance.

Rosin and turpentine are oleoresins obtained from the resin ducts of Pinus species.

Chilgoza (Pinus gerardiana) is a gymnosperm whose seeds are edible and commonly consumed.

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., Araucarias), 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.

Ephedra is an alkaloid chemical compound traditionally obtained from the plant Ephedra sinica. Ephedrine is a medication and stimulant. It is often used to prevent low blood pressure during spinal anesthesia. It has also been used for asthma, narcolepsy, and obesity but is not the preferred treatment. It is of unclear benefit in nasal congestion.

Sequoia sempervirens is a gymnosperm. It is the sole living species of genus Sequoia. Its common names include coast redwood, California redwood. It is an evergreen, long-living monoecious tree.

The oil obtained from Juniperus virginiana, is cedar wood oil and is used in laboratory for microscopic work. Today, cedar oil is often used for its aromatic properties, especially in aromatherapy. Cedar oil is used as an insect repellent, both directly applied to the skin and as an additive to sprays, candles and other products.

Ephedra (Ephedra sinica) is an herb, that has been used in traditional chinese medicine for more than 5,000 years, primarily to treat asthma or bronchitis. Ephedra is also prescribed for symptoms of cold and flu, including nasal congestion, cough, fever, and chills.

Cedrus deodara is a high mountain tree that occurs in a wide range of habitats in the Himalaya. It is also knowns as Deodar and its is in great demand as building material because of its durability, rot-resistant character and good polish taking ability. Thus the correct answer is option A.

• Vascular tissues did not appear in bryophytes. Bryophytes are non-vascular plants. 
• Pteridophytes do not have seeds. Seed formation, first of all, started from angiospermous plants.
• Mycelium is the vegetative part of fungus made up of thread-like structures called hyphae.