Zoology lecture notes and study materials

Difference between Keratinized and Non-keratinized Epithelial Tissues


Keratinized vs Nonkeratinized Epithelium

Keratinized vs Non-keratinized Epithelium
Difference between Keratinized and Non-keratinized Epithelial Tissues

Epithelium constitutes the outer layer of body surfaces, linings of the alimentary canal and the walls of hollow structures. It covers the internal or external surfaces of the body. The functions epithelial tissue is to protect the underlying tissues from physical damages, infection, desiccation, UV radiation and heat loss. Based on the presence of Keratin, the epithelial tissues are categorized into Keratinized epithelium and Non-keratinized epithelial tissues. Keratins are a diverse group of structural proteins that form the intermediate filament network and they provide the structural integrity of keratinized epithelial cells.

The present post discusses the Difference between Keratinized and Non-keratinized Epithelial Cells.

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GATE life Sciences Study Materials

GATE XL 2018 Zoology Solved Question Paper with Answer Key


GATE Zoology Old Question Papers

Official / Original (Previous Year – Old) Solved Question Paper of GATE Life Sciences (XL) 2018 (Zoology) with Answer Key and Explanations as PDF. GATE XL aspirants can download the question paper as single PDF file for your exam preparation. Please feel free to inform us for any mistakes in the answer key provided.

To download the question paper, please click on the download link below the preview…


GATE XL Model Questions GATE XL Previous Year Papers


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Human Physiology Lecture Notes

Difference between A-Band and I-Band of Sarcomere – Comparison Tab


A-band vs I-band

A-Band vs I-Band
Difference between A-Band and I-Band of a Sarcomere

The basic structural and functional unit of a striated muscle is called the Sarcomere. The sarcomere is the repeating units of a striated muscle occur between two Z-lines. This gives the striated appearance of the skeletal or cardiac muscles. The sarcomere composed of myofibrils, an array elongated contractile protein threads found in striated muscle cells. There are two types of myofibrils in the sarcomere called thin filaments and thick filaments. The thin filaments are made of protein called Actin and the thick filaments are made of proteins called Myosin. The actin and myosin filaments in a sarcomere are arranged in a specific manner so that their overlapping and interlocking patterns produce distinct bands when they are observed under a microscope. These bands are technically called as A-bands (Anisotropic) and I-Bands (Isotropic). The present post discusses the Difference between A-bands and I-bands with a comparison table.

Sarcomere diagram

Structure of Sarcomere (Source: Wikipedia)

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Human Physiology Lecture Notes

Difference between Cilia and Microvilli – Comparison Table


cilia vs microvilli

Cilia vs Microvilli
Difference between Cilia and Microvilli

Cilia and microvilli are special types of protuberances from the surface some eukaryotic cells with specific functions such as movement, sensory functions or facilitating absorption.

Cilia (singular – Cilium) are narrow and long hair like protuberances from the apical surface of some epithelial cells. Cilia are made up of microtubules with a length of 5 to 10 µm and 0.2 µm in diameter.

Microvilli (singular – Microvillus) are microscopic cellular membrane protrusions that increase the surface area for absorption. Numerous microvilli together act as a structure called ‘Brush Borders’. The brush borders are abundantly present on the epithelial cells of the small intestine where they facilitate the absorption.

what if cilia and microvilli

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