Railway Science (Biology – Animal Kingdom)

Aves, which includes all birds, have the capacity to regulate their body temperature. Other animals like reptiles, fishes, and amphibians do not possess the ability to regulate their body temperature. Hence, they are cold-blooded animals.

This group of animals is the most successful and diverse in the animal kingdom. Arthropods have a body divided into segments, a hard exoskeleton, and jointed limbs.
Mollusca: Second largest animal group and soft body covered by a calcareous shell. Examples: Snails, oysters, squid, octopuses.
Annelida: Ring body Segment and soft, muscular body. They are aquatic or terrestrial, free-living or parasitic. Examples: Earthworms, leeches, marine worms.

Warm-blooded creatures are animals that can control and keep their body temperature stable. Their four chambered heart completely separates the oxygenated and deoxygenated blood; it pumps only oxygenated blood through the body and deoxygenated blood to the lungs.

All mammals and birds are capable of generating this internal heat and are classed as homoiothermous or warm-blooded animals. The characteristic features of Aves (birds) are the presence of feathers. They possess beaks and forelimbs are modified into wings. Examples : Corvus (Crow), Columba (Pigeon), Psittacula (Parrot).

This type of tissue is well suited to areas in the body subject to constant abrasion. Stratified squamous epithelium: It makes outer protective covering all over the body surface. Ciliated columnar epithelium: It makes the inner lining of the trachea, lungs, respiratory system and buccal chambers. Columnar epithelium: It makes the inner lining of the stomach and intestines.

Adipose - A type of loose connective tissue that stores fat to provide insulation to the body and protect major organs. Epithelial Tissue - The tissue found at the outer layer of skin. It covers the external surface as well as the internal lining of the organs.
Nervous Tissue - Cells of this tissue are called neurons. The brain, Spinal Cord and nerves are made up of this tissue. Muscular Tissue - Consists of elongated cells, also called muscle fibre.

These tissues are widespread throughout the body. They form the covering of all body surfaces, line body cavities and hollow organs, and are the major tissue in glands. They perform a variety of functions that include protection, secretion, absorption, excretion, filtration, diffusion, and sensory reception.

Birds are highly diverse animals that come in many shapes and sizes. Examples of Aves include pelicans, ostriches, hawks, eagles, and owls. All birds have feathers, four-chambered hearts, wings, beaks, and hard-shelled eggs.

Ligament (Connective tissue) : Bands of tissue that help hold bones, joints and organs in place. Areolar (loose connective tissue) - made of cells and an extracellular matrix and present throughout the human body.
Tendon (connective tissue), that attaches muscle to bone. Cartilage is a strong, flexible connective tissue that protects joints and bones.

Connective: These tissues are composed primarily of an extracellular matrix and a limited number of cells. Example - Adipose, cartilage, blood, lymphatic tissues. Parenchyma Tissue (simple permanent tissue) - tissues that have the capacity to split at maturity and assist in wound regeneration and healing. Example - Pith and cortex of stems and roots, mesophyll of leaves. Permanent Tissue - tissues which are specialized and have lost the capacity to divide. Example - Xylem and Phloem. Epidemic - Epidermis is the outer layer of cells covering it protects against water loss, regulates gas exchange, and secretes metabolic compounds.