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
131
Which of the following is considered a very large and diverse group of eukaryotic organisms?
Answer:
algae
Algae represent a polyphyletic, highly diverse group of eukaryotic organisms. They include everything from simple unicellular flagellates to complex multicellular seaweeds, occupying a wide range of ecological niches and exhibiting significant evolutionary variation.
132
To what approximate depth can marine algae be found growing from the seashore?
Answer:
100meter
Marine algae are limited in their vertical distribution by the penetration of sunlight, which is necessary for photosynthesis. While most algae are found in the photic zone, some species can survive at depths of up to 100 meters or more depending on water clarity and the specific pigments they possess to capture light at lower intensities.
133
What is the term for the fusion of gametes that are identical in both size and morphology?
Answer:
isogamy
Isogamy is a form of sexual reproduction involving the fusion of two gametes that are morphologically indistinguishable in size, shape, and motility. This is commonly observed in various algae and fungi, representing a primitive state of sexual reproduction compared to anisogamy or oogamy, where gametes show differentiation.
134
Which pigment is present in excessive amounts in the genus Vaucheria?
Answer:
Beta carotene
Vaucheria species contain photosynthetic pigments including chlorophylls and carotenoids. They are particularly noted for having a high concentration of beta-carotene, which contributes to the characteristic yellowish-green color of the thallus.
135
To which family does the genus Vaucheria belong?
Answer:
vacheriaceae
Vaucheria is a genus of siphonaceous algae. In botanical classification, it is placed within the family Vaucheriaceae, which is characterized by its coenocytic, tubular thallus structure and specific reproductive mechanisms.
136
During indirect lateral conjugation in Spirogyra, what is the functional role of the upper cell?
Answer:
male gametangium
In the process of lateral conjugation in Spirogyra, the cells involved differentiate into gametangia. In indirect lateral conjugation, the upper cell typically functions as the male gametangium, producing the protoplast that migrates through the conjugation tube to fuse with the protoplast of the lower cell, which acts as the female gametangium.
137
What is the term for the smaller, inner valve of a diatom's frustule?
Answer:
hypotheca
The diatom cell wall, or frustule, consists of two overlapping valves. The larger, outer valve is called the epitheca, while the smaller, inner valve that fits inside the epitheca is referred to as the hypotheca.
138
To which taxonomic class does the genus Euglena belong?
Answer:
euglenoidea
Euglena is a well-known genus of flagellated protists classified under the class Euglenoidea. These organisms are characterized by their ability to perform photosynthesis while also being capable of heterotrophic nutrition. They possess a pellicle, which provides structural support, and typically move using one or more flagella.
139
Which researcher is credited with the early study of the chloroplast structure in Spirogyra?
Answer:
Darves
The study of the spiral, ribbon-like chloroplasts in Spirogyra has been a subject of historical botanical research. While the name 'Darves' is cited in this context, it is important to note that historical records on specific early phycological researchers can vary, and this attribution is preserved as per the source material.
140
What is the primary mode of nutrition observed in the majority of algal species?
Answer:
autotrophic
Most algae are photoautotrophic, meaning they possess chlorophyll and other pigments that allow them to synthesize their own organic food from inorganic substances using sunlight as an energy source. While some specialized algae may exhibit mixotrophic or heterotrophic tendencies, autotrophy remains the defining nutritional characteristic of the group.