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
241
Which vegetative structure does ginger utilize for reproduction?
Answer:
rhizomes
Ginger (Zingiber officinale) reproduces vegetatively through rhizomes, which are horizontal, underground stems. These structures store nutrients and allow the plant to spread and generate new shoots from the nodes, facilitating asexual reproduction.
242
How many primary types of tissues are recognized in plant biology?
Answer:
3
Plant tissues are generally categorized into three fundamental systems: dermal tissue (protection), ground tissue (metabolism and support), and vascular tissue (transport). These systems work in concert to maintain the plant's structural integrity, physiological processes, and nutrient distribution throughout its life cycle.
243
What is the primary physiological characteristic that distinguishes permanent tissues from meristematic tissues in plants?
Answer:
divide
Permanent tissues are composed of cells that have completed their growth and differentiation process. Unlike meristematic cells, which retain the ability to undergo continuous mitotic division, permanent tissue cells have lost the capacity to divide and are specialized for specific functions.
244
What term describes the enlarged, distinct regions found along the structure of rhizomes?
Answer:
nodes
Rhizomes are modified underground stems characterized by the presence of nodes and internodes. The nodes are the enlarged portions where buds, leaves, or adventitious roots can develop, serving as points of growth and vegetative propagation.
245
Which cell type forms the outermost single layer bounding the cortex in plants?
Answer:
epidermal cells
The epidermis is the outermost layer of cells in plant organs, including the stem and root. It serves as a protective barrier for the underlying tissues, including the cortex, regulating gas exchange and preventing excessive water loss through transpiration.
246
Which specific type of epithelial tissue lines the bronchi and trachea?
Answer:
ciliated columnar epithelium
The respiratory tract, including the trachea and bronchi, is lined with pseudostratified ciliated columnar epithelium. The cilia play a crucial role in moving mucus and trapped particles away from the lungs, while the goblet cells within the tissue secrete mucus to protect the airway lining.
247
Which plant cells are characterized by their distinct bean-shaped morphology?
Answer:
Guard Cells
Guard cells are specialized plant cells that occur in pairs and exhibit a characteristic bean or kidney shape. They are located in the epidermis of leaves and stems and are responsible for regulating the opening and closing of stomata. By changing their turgor pressure, guard cells control gas exchange and transpiration rates in the plant.
248
What is the primary physiological outcome of the mitotic division occurring within the apical meristems of a plant?
Answer:
increase in plant length
Apical meristems are regions of active cell division located at the tips of roots and shoots. Their primary function is primary growth, which results in the elongation or increase in the length of the plant body.
249
Which of the following correctly identifies the types of plant tissues?
Answer:
ground and epidermal tissues
Plant tissues are categorized into three main systems: dermal (epidermal), ground, and vascular tissues. Unlike animals, plants do not possess nervous tissue. Therefore, ground and epidermal tissues are both valid components of the plant body structure.
250
Where is the cuticle layer typically located in relation to the epidermis to facilitate gaseous exchange?
Answer:
over epidermis
The cuticle is a waxy, protective layer secreted by the epidermal cells of plants. It is located on the outer surface of the epidermis. While it primarily serves to prevent water loss, its presence and the distribution of stomata within the epidermal layer are critical for regulating gaseous exchange.