In pteridophytes the sporophyte produces spores through meiosis. The spores are produced by the sporangia in the spore mother cells. These spores germinate to give rise to gametophytes. The gametophytes bear male and female sex organs. Water is required for transfer of antherozoids - the male gametes released from the male sex organ to the mouth of female sex organ. Fusion of male gamete with the egg result in the formation of zygote. Zygote thereafter produces a multicellular well-differentiated sporophyte. In majority of the pteridophytes all the spores are of similar kinds. However, some genera also produce two kinds of spores, macro (large) and micro (small) spores. The megaspores and microspores germinate and give rise to female and male gametophytes, respectively. In these plants, the female gametophytes are retained on the parent sporophytes for variable periods. The development of the zygotes develop into young embryos within the female gametophytes. This event is a precursor to the seed habit considered an important step in evolution.
Q. In pteridophytes the dominant form of life is the_______.
In pteridophytes the sporophyte produces spores through meiosis. The spores are produced by the sporangia in the spore mother cells. These spores germinate to give rise to gametophytes. The gametophytes bear male and female sex organs. Water is required for transfer of antherozoids - the male gametes released from the male sex organ to the mouth of female sex organ. Fusion of male gamete with the egg result in the formation of zygote. Zygote thereafter produces a multicellular well-differentiated sporophyte. In majority of the pteridophytes all the spores are of similar kinds. However, some genera also produce two kinds of spores, macro (large) and micro (small) spores. The megaspores and microspores germinate and give rise to female and male gametophytes, respectively. In these plants, the female gametophytes are retained on the parent sporophytes for variable periods. The development of the zygotes develop into young embryos within the female gametophytes. This event is a precursor to the seed habit considered an important step in evolution.
Q. In pteridophytes the male and female sex organ of the gametophytes are called ________, respectively.
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In pteridophytes the sporophyte produces spores through meiosis. The spores are produced by the sporangia in the spore mother cells. These spores germinate to give rise to gametophytes. The gametophytes bear male and female sex organs. Water is required for transfer of antherozoids - the male gametes released from the male sex organ to the mouth of female sex organ. Fusion of male gamete with the egg result in the formation of zygote. Zygote thereafter produces a multicellular well-differentiated sporophyte. In majority of the pteridophytes all the spores are of similar kinds. However, some genera also produce two kinds of spores, macro (large) and micro (small) spores. The megaspores and microspores germinate and give rise to female and male gametophytes, respectively. In these plants, the female gametophytes are retained on the parent sporophytes for variable periods. The development of the zygotes develop into young embryos within the female gametophytes. This event is a precursor to the seed habit considered an important step in evolution.
Q. The gametophytes are called as________.
In pteridophytes the sporophyte produces spores through meiosis. The spores are produced by the sporangia in the spore mother cells. These spores germinate to give rise to gametophytes. The gametophytes bear male and female sex organs. Water is required for transfer of antherozoids - the male gametes released from the male sex organ to the mouth of female sex organ. Fusion of male gamete with the egg result in the formation of zygote. Zygote thereafter produces a multicellular well-differentiated sporophyte. In majority of the pteridophytes all the spores are of similar kinds. However, some genera also produce two kinds of spores, macro (large) and micro (small) spores. The megaspores and microspores germinate and give rise to female and male gametophytes, respectively. In these plants, the female gametophytes are retained on the parent sporophytes for variable periods. The development of the zygotes develop into young embryos within the female gametophytes. This event is a precursor to the seed habit considered an important step in evolution.
Q. Pteridophytes are __________ plants.
In pteridophytes the sporophyte produces spores through meiosis. The spores are produced by the sporangia in the spore mother cells. These spores germinate to give rise to gametophytes. The gametophytes bear male and female sex organs. Water is required for transfer of antherozoids - the male gametes released from the male sex organ to the mouth of female sex organ. Fusion of male gamete with the egg result in the formation of zygote. Zygote thereafter produces a multicellular well-differentiated sporophyte. In majority of the pteridophytes all the spores are of similar kinds. However, some genera also produce two kinds of spores, macro (large) and micro (small) spores. The megaspores and microspores germinate and give rise to female and male gametophytes, respectively. In these plants, the female gametophytes are retained on the parent sporophytes for variable periods. The development of the zygotes develop into young embryos within the female gametophytes. This event is a precursor to the seed habit considered an important step in evolution.
Direction : In the above questions the Assertions (A) and Reasons (R) have been put forward. Read both the statements and choose the correct option from the following:
Assertion : In pteridophytes, sporophytic and gametophytic phases are independent.
Reason : The sporophytic plant bears sporangia on the lateral side of leaf-like appendages called sporophylls.
Gametophyte is a dominant phase in the life cycle of a bryophyte. It is more conspicuous, long living, independent, green and freely branched whereas, the sporophytic phase is short lived and dependent upon the gametophyte. The main plant body is haploid and bears sex organs i.e., antheridium and archegonium. Antheridium produces a large number of flagellated male gametes called antherozoids and archegonium is flask shaped with tubular neck and swollen venter. The gametophytic plant body of bryophytes is thalloid in liverworts whereas foliose in mosses. In liverworts, the thallus is differentiated into a dorsal photosynthetic and ventral storage region. In mosses, the gametophyte has two growth stages- protonema stage and leafy stage or gametophore.
Q. Bryophytes require water in their habitat for
Gametophyte is a dominant phase in the life cycle of a bryophyte. It is more conspicuous, long living, independent, green and freely branched whereas, the sporophytic phase is short lived and dependent upon the gametophyte. The main plant body is haploid and bears sex organs i.e., antheridium and archegonium. Antheridium produces a large number of flagellated male gametes called antherozoids and archegonium is flask shaped with tubular neck and swollen venter. The gametophytic plant body of bryophytes is thalloid in liverworts whereas foliose in mosses. In liverworts, the thallus is differentiated into a dorsal photosynthetic and ventral storage region. In mosses, the gametophyte has two growth stages- protonema stage and leafy stage or gametophore.
Q. Plants which produce spores and embryo but lack vascular tissue and seeds are
Gametophyte is a dominant phase in the life cycle of a bryophyte. It is more conspicuous, long living, independent, green and freely branched whereas, the sporophytic phase is short lived and dependent upon the gametophyte. The main plant body is haploid and bears sex organs i.e., antheridium and archegonium. Antheridium produces a large number of flagellated male gametes called antherozoids and archegonium is flask shaped with tubular neck and swollen venter. The gametophytic plant body of bryophytes is thalloid in liverworts whereas foliose in mosses. In liverworts, the thallus is differentiated into a dorsal photosynthetic and ventral storage region. In mosses, the gametophyte has two growth stages- protonema stage and leafy stage or gametophore.
Q. Protonema is ____ .
Gametophyte is a dominant phase in the life cycle of a bryophyte. It is more conspicuous, long living, independent, green and freely branched whereas, the sporophytic phase is short lived and dependent upon the gametophyte. The main plant body is haploid and bears sex organs i.e., antheridium and archegonium. Antheridium produces a large number of flagellated male gametes called antherozoids and archegonium is flask shaped with tubular neck and swollen venter. The gametophytic plant body of bryophytes is thalloid in liverworts whereas foliose in mosses. In liverworts, the thallus is differentiated into a dorsal photosynthetic and ventral storage region. In mosses, the gametophyte has two growth stages- protonema stage and leafy stage or gametophore.
Q. In a moss, sporophyte
Gametophyte is a dominant phase in the life cycle of a bryophyte. It is more conspicuous, long living, independent, green and freely branched whereas, the sporophytic phase is short lived and dependent upon the gametophyte. The main plant body is haploid and bears sex organs i.e., antheridium and archegonium. Antheridium produces a large number of flagellated male gametes called antherozoids and archegonium is flask shaped with tubular neck and swollen venter. The gametophytic plant body of bryophytes is thalloid in liverworts whereas foliose in mosses. In liverworts, the thallus is differentiated into a dorsal photosynthetic and ventral storage region. In mosses, the gametophyte has two growth stages- protonema stage and leafy stage or gametophore.
Direction : In the following questions the Assertions (A) and Reasons (R) have been put forward. Read both the statements and choose the correct option from the following :
Assertion : Moss protonema resemble green alga.
Reason : It develops unicellular sex-organs.
The gymnosperms are a group of seed-producing plants that includes conifers, cycads, Ginkgo, and gnetophytes. Gymnosperms are either shrub or tree. In some genera, roots are in association with fungi in the form of mycorrhiza. In some other genera of gymnosperms, roots are associated with nitrogen-fixing. In gymnosperms ovules are naked without any covering and hence remain exposed. The seeds, which develop after fertilization, are also naked. The seeds develop either on the surface of scales or leaves, which are often modified to form cones The leaves may be simple or compound. Some has pinnately compound leaves or needlelike leaves with thick cuticle and sunken stomata. The gymnosperms are heterosporous. Sporangia are formed on sporophylls which are arranged spirally along an axis to form compact strobili or cones.
Q. Which statement is incorrect about gymnosperms?
The gymnosperms are a group of seed-producing plants that includes conifers, cycads, Ginkgo, and gnetophytes. Gymnosperms are either shrub or tree. In some genera, roots are in association with fungi in the form of mycorrhiza. In some other genera of gymnosperms, roots are associated with nitrogen-fixing. In gymnosperms ovules are naked without any covering and hence remain exposed. The seeds, which develop after fertilization, are also naked. The seeds develop either on the surface of scales or leaves, which are often modified to form cones The leaves may be simple or compound. Some has pinnately compound leaves or needlelike leaves with thick cuticle and sunken stomata. The gymnosperms are heterosporous. Sporangia are formed on sporophylls which are arranged spirally along an axis to form compact strobili or cones.
Q. The mycorrhizal relationship between a fungus and the roots is found in
The gymnosperms are a group of seed-producing plants that includes conifers, cycads, Ginkgo, and gnetophytes. Gymnosperms are either shrub or tree. In some genera, roots are in association with fungi in the form of mycorrhiza. In some other genera of gymnosperms, roots are associated with nitrogen-fixing. In gymnosperms ovules are naked without any covering and hence remain exposed. The seeds, which develop after fertilization, are also naked. The seeds develop either on the surface of scales or leaves, which are often modified to form cones The leaves may be simple or compound. Some has pinnately compound leaves or needlelike leaves with thick cuticle and sunken stomata. The gymnosperms are heterosporous. Sporangia are formed on sporophylls which are arranged spirally along an axis to form compact strobili or cones.
Q. Gymnosperms are
The gymnosperms are a group of seed-producing plants that includes conifers, cycads, Ginkgo, and gnetophytes. Gymnosperms are either shrub or tree. In some genera, roots are in association with fungi in the form of mycorrhiza. In some other genera of gymnosperms, roots are associated with nitrogen-fixing. In gymnosperms ovules are naked without any covering and hence remain exposed. The seeds, which develop after fertilization, are also naked. The seeds develop either on the surface of scales or leaves, which are often modified to form cones The leaves may be simple or compound. Some has pinnately compound leaves or needlelike leaves with thick cuticle and sunken stomata. The gymnosperms are heterosporous. Sporangia are formed on sporophylls which are arranged spirally along an axis to form compact strobili or cones.
Q. The largest group of living gymnosperms are the
The gymnosperms are a group of seed-producing plants that includes conifers, cycads, Ginkgo, and gnetophytes. Gymnosperms are either shrub or tree. In some genera, roots are in association with fungi in the form of mycorrhiza. In some other genera of gymnosperms, roots are associated with nitrogen-fixing. In gymnosperms ovules are naked without any covering and hence remain exposed. The seeds, which develop after fertilization, are also naked. The seeds develop either on the surface of scales or leaves, which are often modified to form cones The leaves may be simple or compound. Some has pinnately compound leaves or needlelike leaves with thick cuticle and sunken stomata. The gymnosperms are heterosporous. Sporangia are formed on sporophylls which are arranged spirally along an axis to form compact strobili or cones.
Direction : In the above questions the Assertions (A) and reasons (r) have been put forward. read both the statements and choose the correct option from the following :
Assertion : Cycas, roots are called coralloid roots.
Reason : Their pinnate compound leaves persist for few years.