This article covers important Botany questions and answers on Ascomycotina, Mycorrhiza, Disease Triangle, hypoplastic symptoms, Bryophytes, cambium, secondary growth, cyanobacteria, and diatoms. These short questions and answers are useful for B.Sc. Botany examination preparation and quick revision.
1. State two characteristic features of Ascomycotina.
Answer: The two main characteristic features of Ascomycotina are:
Reproductive structure: They produce specialized reproductive structures called asci (singular: ascus), which contain spores called ascospores.
Hyphal structure: Ascomycotina are typically filamentous fungi with septate hyphae, meaning their hyphae are divided into compartments by septa.
2. What is Mycorrhiza?
Answer: Mycorrhiza is a symbiotic association between fungi and the roots of plants.
3. What is Disease Triangle?
Answer: The Disease Triangle is a conceptual model consisting of three essential factors required for the development of a plant disease: a susceptible host, a pathogen, and a favourable environment.
or
The disease triangle illustrating the phenomenon of plant disease as the interior space of the disease triangle is a conceptual model that shows the interactions between environment, the host and infectious agent. This model can be used to predict epidemiological outcomes in plant health and public health, both in local and global communities.
4. What are hypoplastic symptoms?
Answer: Hypoplastic symptoms are manifestations caused by slowed development or underdevelopment of an affected tissue or organ. They result from hypoplasia, which is characterized by subnormal cell division and, rarely, degeneration of cells.
5. What are peristome teeth?
Answer: Peristome teeth are tooth-like projections surrounding the mouth of the capsule in most members of Bryidae (mosses) of Bryophytes. They help in the controlled release of spores.
6. What is Calyptra?
Answer: A calyptra is a protective, cap-like or hood-like structure that covers the developing spore capsule in bryophytes, particularly in mosses. It develops from the enlarged archegonial venter and protects the young capsule.
7. What is Cambium? Mention its features.
Answer: Cambium is a lateral meristematic tissue present in the stems and roots of vascular plants. It produces secondary tissues and contributes to the increase in thickness or girth of the plant.
Features of Cambium
Cambial cells are meristematic and undergo active cell division, mainly by periclinal divisions.
Cambium is responsible for increasing the diameter of stems and roots by producing secondary xylem and secondary phloem.
8. What is Secondary Growth of a Plant?
Answer: Secondary growth is the increase in the thickness or girth of stems and roots resulting from the activity of lateral meristems, mainly the vascular cambium and cork cambium.
or
Secondary growth is the growth that results from cell division in the cambia or lateral meristems i.e., vascular and cork cambium and that causes the stems and roots to thicken i.e., increase in girth.
9. Name two cyanobacteria used as biofertilizers.
Answer: Two cyanobacteria commonly used as biofertilizers are:
Anabaena
Nostoc
They are particularly important in improving soil fertility through biological nitrogen fixation.
10. What is Raphe? How does it differ from Pseudoraphe?
Answer: A raphe is a true longitudinal slit or channel in the silica cell wall (frustule) of certain diatoms. It enables these diatoms to move over surfaces.
A pseudoraphe is an unornamented or clear longitudinal area that resembles a raphe but does not have a true opening or slit.
Difference between Raphe and Pseudoraphe
| Raphe | Pseudoraphe |
|---|---|
| It is a true slit or channel in the frustule. | It is a clear area that resembles a raphe. |
| It is associated with movement in raphid diatoms. | It lacks a true opening or functional raphe. |
These important Botany questions and answers provide a quick revision guide for B.Sc. Botany students. The topics cover important concepts from Mycology, Plant Pathology, Bryophytes, Plant Anatomy, Plant Physiology, Cyanobacteria, and Diatoms.
Disclaimer
The questions, answers, definitions, examples, and other information presented in this article have been compiled and prepared from various educational, academic, botanical, taxonomic, and publicly available sources. The content is provided solely for educational and academic purposes to help students understand and revise important concepts in Plant Taxonomy.
