Botany MCQs
Topic Notes: Botany
MCQs and preparation resources for competitive exams, covering important concepts, past papers, and detailed explanations.
Plato
- Biography: Ancient Greek philosopher (427–347 BCE), student of Socrates and teacher of Aristotle, founder of the Academy in Athens.
- Important Ideas:
- Theory of Forms
- Philosopher-King
- Ideal State
141
The genus Plasmodiophora belongs to which taxonomic group?
Answer:
plasmodiophore
The genus Plasmodiophora is the type genus for the group commonly referred to as plasmodiophorids. These are obligate endoparasitic protists that infect plants. The classification provided in the option refers to the group name derived from the genus.
142
How many classes are typically identified within the Deoxyvira group?
Answer:
three
The classification of viruses into 'Deoxyvira' (DNA viruses) often involves grouping them based on structural and replication characteristics. In certain historical or specific academic frameworks, this group is divided into three primary classes based on the nature of their DNA genome, such as double-stranded, single-stranded, or complex DNA structures.
143
What is the taxonomic division for the genus Plasmodiophora?
Answer:
plasmodiophoromycota
In biological classification, the genus Plasmodiophora is placed within the division Plasmodiophoromycota. This division encompasses a group of obligate endoparasitic protists that infect plants, often causing significant agricultural diseases such as clubroot in cruciferous crops.
144
Which viral family is associated with the group often referred to as Deoxyhelica?
Answer:
poxvirindae
The Poxviridae family represents a significant group of large, complex DNA viruses. While the term 'Deoxyhelica' is not standard taxonomic nomenclature, the question refers to the classification of DNA-containing viruses. Poxviridae are well-studied for their unique replication strategies and large genome sizes compared to other DNA virus families.
145
How many major categories of RNA-based viruses are typically recognized in basic virology classification?
Answer:
two
RNA viruses are often broadly categorized based on the polarity of their genome into positive-sense (+) RNA viruses and negative-sense (-) RNA viruses. Positive-sense RNA can act directly as mRNA, while negative-sense RNA must be transcribed into a complementary positive strand before protein synthesis can occur within the host cell.
146
To which group of fungi does the genus Tuber belong?
Answer:
truffles
The genus Tuber consists of hypogeous (underground) ascomycete fungi commonly known as truffles. They are highly prized in culinary arts for their distinct aroma and flavor and form mycorrhizal associations with the roots of specific trees.
147
What is the taxonomic classification of the genus Ustilago?
Answer:
ustilago
The question asks for the genus name itself. Ustilago is the genus name, which belongs to the family Ustilaginaceae and the order Ustilaginales within the class Basidiomycetes. The provided answer identifies the genus correctly.
148
How many nuclei are typically contained within each plasmodium of the organism in question?
Answer:
30
The plasmodium is a multinucleate mass of protoplasm. In specific biological contexts regarding certain primitive fungal groups, the number of nuclei within a plasmodial unit is often cited in literature as approximately 30. This multinucleate state allows the organism to grow and move as a single unit while maintaining genetic material throughout its vegetative body.
149
How is the morphology of a Spirillum bacterium best described?
Answer:
thick rigid spiral
Spirilla are characterized by a rigid, helical, or spiral-shaped cell body. Unlike spirochetes, which are flexible and move via axial filaments, Spirillum species maintain their spiral shape and typically move using flagella.
150
What mechanism describes the specific interaction between viral surface proteins and host cell receptors during the initial stage of infection?
Answer:
lock and key
The 'lock and key' model refers to the high specificity of the interaction between viral attachment proteins (the key) and specific receptors on the host cell surface (the lock). This precise molecular recognition ensures that viruses only infect susceptible host cells that possess the appropriate surface markers.