Railway Science (Biology – Plant Kingdom) (Part-II)

Transpiration is the loss of water from the plant through evaporation at the leaf surface. Respiration - The sequence of events that results in the exchange of oxygen and carbon dioxide between the atmosphere and the body cells. Excretion - The process of removal of metabolic wastes from the body.

Parenchyma: Simple permanent tissue. It consists of relatively unspecialised cells with thin cell walls. They are usually loosely arranged, thus large spaces between cells (intercellular spaces) are found in this tissue. They store food. Xylem - Transports water and dissolved minerals from the roots to the leaves. It is unidirectional. Sclerenchyma - Provides strength and rigidity to plant tissues. Example: Coconut husk. Collenchyma - Provides flexible support to plant tissues and support to stems.

Parenchyma - Found in soft plant parts, including Leaf mesophyll, Flowers, Fruits, and Young stems. It is also present in petiole, ground tissue and vascular bundles.
Phloem - The vascular tissue in plants which transport organic nutrients and other metabolic products from the leaves.
Sclerenchyma - Provide mechanical support and strength to the plants. Example: Husk of the coconut.
Collenchyma - Provide support and protection. Example: The strands in celery stalks.

There are 2 types of root system: (i) Tap root system - It is the main root system of dicotyledonous plants. Example - Gram, Chinarose, Neem. (ii) Fibrous root system - It is the main root system of monocotyledonous plants. Example - Maize, Grass and Wheat. Dicot plants have two cotyledons in seeds whereas Monocots have only one cotyledon within the seeds.

Thallophyta (Algae) : A division of the plant kingdom including primitive forms of plant life showing a simple plant body, including unicellular to large algae, fungi, lichens.
Bryophytes - A familiar group of non-vascular, nonflowering and seedless plants. Mosses, hornworts and liverworts are together referred to as bryophytes.
Gymnosperms (Naked seeds) - Flowerless plants that produce cones and seeds.
Pteridophytes - Vascular plants that reproduce using spores. They do not produce flowers and seeds and hence are also known as cryptogams.

Rhizome - A horizontal underground plant stem capable of producing the shoot and root systems of a new plant. Examples - Bamboo, turmeric, lotus, asparagus. Function - To store starches and proteins and enable plants to perennate (survive an annual unfavorable season) underground.
Reproduction - Vegetative Reproduction. Types - Underground Rhizomes (hops, poison oak, grass species), Above-ground Rhizomes (plant species include ferns and irises), Multi-layered Rhizomes (Giant Horsetails).

The seeds of plants with two cotyledons are known as dicotyledons. Examples : Apples, mango, peas. Ulva - This is a small genus of marine and brackish water green algae. It is edible and is often called 'Sea Lettuce'.
Cedars are evergreen trees that belong to the pine family. Pine - Any of a genus of evergreen trees that have narrow needles for leaves, cones, and wood ranging from very soft to hard.

The hierarchy of plant classification is indeed based on shared characteristics and evolutionary relationships, but it is organized into various taxonomic ranks such as kingdom, division (or phylum for animals), class, order, family, genus, and species.

Cedar belongs to the group of plants called gymnosperms, which have uncoated or naked seeds. The seeds are not enclosed in a fruit, but are exposed on the surface of cones or scales.

Sclerenchyma is a type of permanent tissue found in plants. It is a supportive tissue and is usually made up of dead cells with highly thickened lignified walls. Parenchyma is the most common simple permanent tissue.
It generally stores food and in some situations, it contains chlorophyll and performs photosynthesis, and then it is called Collenchyma.