In which plant will you look for mycorrhiza and coralloid roots? Also, explain what these terms mean.
Mycorrhiza, which is also known as ‘fungus-root’, is basically a mutually beneficial relationship between that of plant root and a fungus. In most cases, the fungus grows within the roots of the plants and helps the plant to absorb water and nutrients, and in return, the plant provides the fungus with food. E.g., Pinus. In some cases, the fungus could be harmful to the plants.
Coralloid Roots: These roots are associated with nitrogen-fixing cyanobacteria. In coralloid roots, the nodules are formed in large numbers, in the roots giving them coralloid appearance. E.g. Cycas and plants of Leguminosae.
View Full Answer(1)How are the male and female gametophytes of pteridophytes and gymnosperms different from each other
The size of gametophyte of of pteridophytes quite large compare to gymnosperm's gametophytes. Gametophyte of pteridophytes are photosynthetic in nature while gametophyte of gymnosperms are are not photosynthetic in nature
View Full Answer(2)Comment on the lifecycle and nature of a fern prothallus
Fern, which is a type of pteridophytes; reveals a haplo-diplontic state. In this situation, both the stages of gametophytic and sporophytic are multicellular. The diploid sporophyte is represented by a prepotent and independent, photosynthetic, vascular plant body. The haploid gametophyte, which is also independent in nature, but the duration of its life is shorter than that of the sporophytes.
View Full Answer(1)Draw labelled diagrams of the following:
(a) Female and male thallus of a liverwort.
(b) Gametophyte and sporophyte of Funaria.
(c) Alternation of generation in Angiosperm.
Ans. (a) Female and male thallus of a liverwort:
(b) Funaria, gametophyte and sporophyte: -
(c) Alternation of generation in Angiosperm:
View Full Answer(1)
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Explain why sexual reproduction in angiosperms is said to take place through double fertilisation and triple fusion. Also, draw a labelled diagram of embryo sac to explain the phenomena.
Ans. In the process of double fertilisation in case of angiosperms; one male gamete fuses with the female gamete, and the second male gamete fuses with the secondary nucleus. This fusion of the male and female gametes results in the outcome of the zygote. And the fusion between the second male gamete and the secondary nucleus results in the outcome of the primary endosperm nucleus. Since two occurrences of fusion of nuclei take place, thus it is called double fertilisation. These following figures show double fertilisation:
View Full Answer(1)Lichen is usually cited as an example of ‘symbiosis’ in plants where an algal and a fungal species live together for their mutual benefit. Which of the following will happen if algal and fungal partners are separated from each other?
(a) Both will survive and grow normally and independent of each other.
(b) Algal components will survive while the fungal component will die.
(c) Both will die
(d) The Fungal component will survive while the algal partner will die.
Based on the answer, how do you justify this association as symbiosis?
Ans. Option(c) is the correct, i.e. both will die.
Explanation: The process of ‘symbiosis’ explains that the plant and the fungus which are growing together depend on each other for nutrients and if they are bound to get separated, they will both die because they are codependent.
View Full Answer(1)With the help of a schematic diagram, describe the haplo-diplontic life cycle pattern of a plant group.
Ans. Pteridophyte and Bryophyte both reveal a haplo-diplontic life cycle. The diploid phase is not independent in bryophytes; however, it is independent in the case of pteridophytes. Furthermore, the sporophyte is more clearly visible in the case of pteridophytes than in bryophytes.
View Full Answer(1)Gametophyte is a dominant phase in the life cycle of a bryophyte. Explain.
Ans
The dominant phase in bryophytes is represented by gametophytic plants. The gametophyte is self-reliant, photosynthetic, and erect. Antheridia and archegonia are developed and found on the gametophyte. These male and female organs are multicellular in nature. The Antheridia and Archegonia carry the male and female gametes. The antheridium produces biflagellate antherozoids, while the archegonium produces a single egg. Water helps to carry the antherozoids to the archegonium. The antherozoids flagellate, which gives them the feature to be motile. After the process of fertilisation, the zygote is formed. The zygote develops into a multicellular figure called a sporophyte.
The sporophyte in bryophytes is smaller comparably and is not self-reliant. The sporophyte is attached to the gametophyte and gets it nutrition from the gametophyte. The gametophyte has control over the life cycle of a bryophyte in every phase. The gametophyte is self-independent and photosynthetic. The size of the gametophyte is larger in size as compared to the sporophyte. Also, the sporophyte is not independent and holds on to the gametophyte for nutrition.
View Full Answer(1)In which plant will you look for mycorrhiza and coralloid roots? Also, explain what these terms mean.
Ans. Mycorrhiza, which is also known as ‘fungus-root’, is basically a mutually beneficial relationship between that of plant root and a fungus. In most cases, the fungus grows within the roots of the plants and helps the plant to absorb water and nutrients, and in return, the plant provides the fungus with food. E.g., Pinus. In some cases, the fungus could be harmful to the plants.
Coralloid Roots: These roots are associated with nitrogen-fixing cyanobacteria. In coralloid roots, the nodules are formed in large numbers, in the roots giving them coralloid appearance. E.g. Cycas and plants of Leguminosae.
View Full Answer(1)Comment on the lifecycle and nature of a fern prothallus.
Answer.
Fern, which is a type of pteridophytes; reveals a haplo-diplontic state. In this situation, both the stages of gametophytic and sporophytic are multicellular. The diploid sporophyte is represented by a prepotent and independent, photosynthetic, vascular plant body. The haploid gametophyte, which is also independent in nature, but the duration of its life is shorter than that of the sporophytes.
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In which plant will you look for mycorrhiza and coralloid roots Also explain what these terms mean.
How are the male and female gametophytes of pteridophytes and gymnosperms different from each other
Comment on the lifecycle and nature of a fern prothallus
Gametophyte is a dominant phase in the life cycle of a bryophyte Explain
In which plant will you look for mycorrhiza and coralloid roots Also, explain what these terms mean