General Science/Everyday Science MCQs
Topic Notes: General Science/Everyday Science
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
71
What is 'etiolation'?
Answer:
Plant adaptations for growing in darkness
Etiolated plants grow rapidly tall, have pale stems, and unexpanded leaves. This is a survival strategy to reach light as quickly as possible when buried or shaded.
72
Which plant part is a 'sink' in terms of sugar transport?
Answer:
A growing fruit
A sugar sink is an organ that consumes or stores sugar, such as roots, tubers, fruits, or growing shoot tips. Mature leaves are typically sugar sources.
73
What is the 'periderm'?
Answer:
The protective tissue that replaces the epidermis in woody plants
As woody plants undergo secondary growth, the epidermis ruptures. The cork cambium produces periderm, which consists of cork and phelloderm, creating a protective 'outer skin'.
74
In the leaf, 'venation' refers to the pattern of:
Answer:
Vascular bundles
Venation is the arrangement of veins (vascular bundles) in the leaf lamina. Monocots typically have parallel venation, while dicots have reticulate (net-like) venation.
75
Which cells in the xylem are essentially long, thin pipes with perforated end plates?
Answer:
Vessel elements
Vessel elements are wider and shorter than tracheids. They are aligned end-to-end to form long continuous tubes (vessels) with perforated end walls for rapid water movement.
76
What is the main driver of 'guttation'?
Answer:
Root pressure
Guttation is the exudation of water droplets from leaves, usually at night. It occurs when high soil moisture and low transpiration lead to positive root pressure, forcing water out through specialized pores called hydathodes.
77
The vascular tissue of a root is organized into a central cylinder called the:
Answer:
Stele
The stele (or vascular cylinder) contains the xylem and phloem. In many dicot roots, the xylem forms a star shape in the center with phloem tucked between the arms.
78
Which structure in seeds is the first to emerge during germination?
Answer:
Radicle (embryonic root)
The radicle is the first organ to emerge. This allows the seedling to anchor itself in the soil and begin absorbing water, which is essential for further growth.
79
What is the 'zone of elongation' in a root tip?
Answer:
Where cells increase in length, pushing the root tip forward
In the zone of elongation, cells take up water and expand. This expansion provides the mechanical force needed to drive the root further into the soil.
80
Which plant structure contains the 'sporangia' where spores are produced?
Answer:
Sporophyte
The sporophyte is the diploid generation of a plant. It produces haploid spores through meiosis within structures called sporangia.