Biology MCQs
Topic Notes: Biology
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
231
What is the term for the protective, waxy coating found on the surface of plant leaves and stems?
Answer:
cuticle
The cuticle is a protective, hydrophobic, waxy layer composed primarily of cutin and waxes. It covers the epidermis of leaves, young shoots, and other aerial plant organs to minimize water loss through transpiration and provide a barrier against pathogens and environmental stress.
232
Which of the following organisms serves as a classic example of plants possessing intercalary meristem?
Answer:
grasses
Intercalary meristems are found at the bases of leaves or internodes in monocotyledonous plants, such as grasses. This type of meristematic tissue allows for rapid elongation and regrowth of stems and leaves, which is an evolutionary adaptation that enables grasses to survive grazing by herbivores.
233
Which branch of biology is dedicated to the study of the physical form and external structure of living organisms?
Answer:
morphology
Morphology is the branch of biology that deals with the study of the form, shape, and structure of organisms and their specific structural features. It encompasses both external morphology (the study of the outer appearance) and internal morphology (anatomy), providing a foundational understanding of biological diversity and evolutionary adaptations.
234
Where are meristematic tissues primarily located in plants?
Answer:
roots and shoots
Meristematic tissues are regions of actively dividing cells responsible for plant growth. They are primarily located at the apical regions of roots and shoots, known as apical meristems, which facilitate primary growth by increasing the length of the plant body.
235
Which type of plants are known to excrete waste materials in the form of mucilage?
Answer:
carnivorous plants
Many carnivorous plants, such as those in the genus Drosera, secrete mucilage from glandular hairs. This sticky substance serves a dual purpose: it traps small insects for nutrient acquisition and acts as a mechanism for excreting certain metabolic waste products.
236
What is the term for the small pores found in the bark of woody stems that facilitate gas exchange?
Answer:
lenticels
Lenticels are porous tissues consisting of cells with large intercellular spaces in the periderm of the secondarily thickened stems and roots of woody plants. They function as pores, allowing for the exchange of gases between the internal tissues of the stem and the external atmosphere.
237
Which biological term describes a structure composed of groups of similar cells organized into sheets or bundles to perform a specific function?
Answer:
Tissue
A tissue is a fundamental level of biological organization consisting of a group of structurally similar cells that work together to perform a specialized function. Tissues are organized into various patterns, such as sheets or bundles, and serve as the building blocks for organs within multicellular organisms, ensuring efficient physiological operation.
238
What is the primary function of the epidermal tissues found in plant roots?
Answer:
water absorption
The epidermis of the root, often featuring specialized root hairs, is specifically adapted to maximize the surface area available for the absorption of water and dissolved minerals from the soil. This tissue acts as the primary interface between the plant and the soil environment, facilitating essential nutrient uptake.
239
Which vegetative reproductive structure is utilized by tulips and onions for propagation?
Answer:
bulbs
Tulips and onions reproduce vegetatively through specialized underground storage organs known as bulbs. A bulb consists of a short stem base surrounded by fleshy, scale-like leaves that store nutrients, allowing the plant to survive dormant periods and regenerate new growth during the favorable growing season.
240
What term describes the clusters of dormant buds found on stem tubers?
Answer:
eyes
In botany, stem tubers such as those found in potatoes possess specialized areas known as 'eyes'. These eyes are actually axillary buds located at nodes on the stem, which are capable of sprouting and developing into new shoots under favorable environmental conditions, serving as a primary method of vegetative propagation.