RRB Group D Science Botany: Core Disciplines, Plant Structure & Processes

Botany is the branch of biological science that deals with the study of plants, including their structure, properties, and biochemical processes. The term originates from the Greek word for "pasture" or "grass." Known as the Father of Botany, Theophrastus earned this title by authoring the monumental work Historia Plantarum, where he detailed the morphology of over 500 different plant species.

Botany is an important part of the General Science section in the RRB Group D exam. This section carries 25% of the total weightage, with Biology typically accounting for 6–8 questions. Botany questions are generally factual and concept-based, making them a high-scoring opportunity for students who master the Class 10 NCERT curriculum. Here, Arti ma’am explains all the important concepts of Botany for RRB Group D exam.

Core Disciplines within Botany

To master the study of plants, botanists divide the field into several specialized areas:

1. Plant Morphology: This refers to the study of the external structure of plants—how they look from the outside (roots, stems, leaves, flowers).

2. Plant Anatomy: Unlike morphology, anatomy focuses on the internal structure. It involves looking inside the plant tissues, much like studying the internal organs of a human.

3. Plant Physiology: This is the study of functional processes such as respiration, transpiration, and the most vital process: photosynthesis.

4. Plant Taxonomy: This involves the grouping and classification of plants based on shared characteristics to give them a distinct identity.

5. Plant Pathology: The study of plant diseases caused by bacteria, viruses, or fungi, and how to treat them.

Plant Structure: Roots, Stems, and Leaves

Every plant begins its journey from a seed. When a seed germinates, it develops two main parts: the Radicle, which forms the root system, and the Plumule, which develops into the shoot system (stems, leaves, and flowers).

• Root System: Roots absorb minerals and water from the soil. They are categorized into Taproots (deep-growing, like carrots) and Fibrous roots (thread-like networks, like grass).

• Stem: Stems provide structural support and act as a highway for transporting nutrients. Interestingly, some items we think are roots are actually modified stems, such as potatoes, ginger, and turmeric.

• Leaves: Often called the "kitchen of the plant," leaves are the primary site for photosynthesis. They take in CO2 and sunlight to produce glucose (food) for the plant.

Vital Processes: Photosynthesis and Respiration

Photosynthesis is the process by which plants use chlorophyll to convert sunlight, water, and carbon dioxide into glucose and oxygen. While oxygen is essential for us, it is actually a waste product for the plant!

Respiration is equally important. While plants produce oxygen during the day via photosynthesis, they perform respiration 24/7. At night, when photosynthesis stops, plants take in oxygen and release carbon dioxide, which is why it is often advised not to sleep under trees at night.

Transpiration is the evaporation of excess water through tiny pores in leaves called stomata. This process helps keep the plant cool and facilitates the upward movement of minerals from the roots.

Plant Tissues: The Building Blocks

Plant tissues are broadly classified into two groups:

• Meristematic Tissue: These are actively dividing cells responsible for growth.

• Permanent Tissue: These are divided into Simple (Parenchyma, Collenchyma, Sclerenchyma) and Complex.

  • Xylem: Transports water and minerals in a unidirectional (upward) flow.

  • Phloem: Transports food (glucose) in a bidirectional flow to all parts of the plant.