What is Ephedra female cone?
The female cone of Ephedra (Fig. 1) comprises cone bracts in decussate arrangement or in whorls of three. In the axil of the most distal pair or whorl of bracts there are one to three ovule(s), each surrounded by a seed envelope (Figs 1, 2).
Is Ephedra a cone bearing plant?
The Ephedraceae are distinguished in being mostly dioecious shrubs, vines, or small trees with narrow, striate, photosynthetic aerial stems, the leaves scale-like, opposite or whorled, the pollen cones with decussate bracts subtending microsporangiophores, each bearing apical synangia and subtended by an outer bract …
Do Ephedra have ovaries?
Reproduction. Like all seed plants, Ephedra produces female gametophytes inside ovules.
How many ovules are found in female flower of Ephedra?
The extant Ephedra as well as the new fossil species have orthotropous ovules, and each ovulate cone can have one to three ovules (always two in the new fossil species) positioned in the axils of the distalmost whorl of sterile bracts (Rydin et al.
What is Pinus male cone?
Pinus is a gymnosperm. The male plant bears male strobilus or male cone. It is formed by the aggregation of microsporophylls. The microsporophylls are arranged spirally and each microsporophyll has 2 microsporangia which are arranged abaxially (away from the stem or leaves).
What is Ephedra for?
Ephedra (Ephedra sinica), also called ma huang, is an herb that has been used in Traditional Chinese Medicine (TCM) for more than 5,000 years, primarily to treat asthma, bronchitis, and hay fever. Ephedra is also prescribed for symptoms of cold and flu, including nasal congestion, cough, fever, and chills.
Is Ephedra dioecious?
The plants are mostly dioecious: with the pollen strobili in whorls of 1–10, each consisting of a series of decussate bracts.
Why Ephedra plant is known as connecting link between angiosperms and gymnosperms?
Which plants are the collecting link between angiosperms and gymnosperms? Advanced gymnosperms such as Gnetum, Ephedra and Welwitschia belonging to the order Gnetales act as connecting link between gymnosperms and angiosperms. They show resemblance to both gymnosperms and angiosperms.
Why Ephedra plant is known as a connecting link between angiosperms and gymnosperms?
Why Ephedra is called jointed?
In Ephedra the stems have finely ridged joints, the basis for the common name joint fir. Superficially, the stems resemble those of the genus Equisetum. The leaves are arranged in pairs on the stem or in whorls of three with their bases forming a sheath around the stem at a node.
How many cells are present in the male gametophyte of Ephedra at the time of pollination?
Development of male gametophyte before pollination: The four cells of the tetrad separate and develop into microspores. The microspore divides by a transverse wall to form a small prothallial cell and a large outer cell is (Fig. 13 A).
What is female cone?
The female cone (megastrobilus, seed cone, or ovulate cone) contains ovules which, when fertilized by pollen, become seeds. The female cone structure varies more markedly between the different conifer families, and is often crucial for the identification of many species of conifers.
Does Cycas have female cone?
-Cycas is a genus of plant which has no female cones but reproduction occurs by bulbils for vegetative propagation.
What type of drug is Ephedra?
Ephedra is a stimulant herb usually from the stem and branches of Ephedra sinica. Most ephedra species contain the chemical ephedrine. It’s banned in the US. The ephedrine in ephedra is responsible for its therapeutic effects and also its serious safety concerns.
What is the difference between ephedrine and Ephedra?
Ephedrine is a chemical contained in the ephedra herb. Ephedrine has medical uses, mostly in operating rooms and intensive care units. Its chemical properties raise blood pressure and heart rate and open up the large air passages in the lungs.
Why is Ephedra jointed?
The branches are also green and photosynthetic &arise in the axils of scale leaves. The stem is distinctly jointed and differentiated into nodes and internodes. Hence , the plants are commonly called ‘Jointed fir’.
What are angiosperm features of Ephedra plant?
Xylem consists of tracheids, vessels and xylem parenchyma. Due to the presence of the vessels the Ephedra resembles angiosperms. The phloem consists of sieve cells, phloem parenchyma and albuminous cells. Phloem and xylem are separated by a narrow strip of cambium.
Why Ephedra is called jointed fir?
Stem: The stem is green, woody, hard, glabrous and much branched. The branches are also green and photosynthetic &arise in the axils of scale leaves. The stem is distinctly jointed and differentiated into nodes and internodes. Hence , the plants are commonly called ‘Jointed fir’.
Is Ephedra a gymnosperm?
ephedra, (genus Ephedra), genus of 65 species of gymnosperm shrubs of the family Ephedraceae. Ephedra is an evolutionally isolated group and is the only genus in the order Ephedrales (division Gnetophyta). Species are distributed in dry regions in both the Eastern and Western hemispheres.
What are angiosperms features of Ephedra?
How many cells are present in the male gametophyte of Ephedra at the time of pollination Mcq?
The male gametophyte, also called the pollen grain or microgametophyte, develops within the anther and consists of two sperm cells encased within a vegetative cell (Gifford and Foster, 1989).
How many cells are found in female gametophyte?
There are usually 8 haploid cells in the female gametophyte of a flowering plant: 3 antipodal cells (at the opposite end of the embryo sac from the egg) 2 synergids flanking the egg (located at the micropylar end of the embryo sac)
What is female cone and male cone?
Did you know that some cones are female, and others are male? Female cones are the big cones you’d picture when you think of pine cones. They have a seed in their open scales that becomes a new tree when it gets pollen from a male cone. Male cones are a lot smaller than female cones and their scales aren’t as open.
What is the difference between male and female cones?
Much like humans, coniferous trees have specialized male and female sex organs. male pine cones have close-knit “scales,” that hold pollen sacks, the pollen acting as air-borne “sperm;” female pine cones have looser scales and lie lower on a tree to make pollination easier.
What is the male cone of Cycas?
The male cone of Cycas is probably the largest in the plant kingdom (40-80 cm). it is a compact, woody, conical or oval structure attached to the tip of the stem by a short stalk. Initially the cone is terminal but later it becomes lateral.