Monday, 27 May 2024

Taxonomy and Systemtics

Taxonomy and systematics are essential branches of biology that focus on the classification, identification, and evolutionary relationships of living organisms. While they are closely related and often used interchangeably, they have distinct roles and scopes within biological sciences. Here’s an overview of both fields:

Taxonomy

Taxonomy is the science of naming, describing, and classifying organisms. It involves several key activities:

  1. Identification: Identification is determining and recording the characteristics of an organism, then comparing these characteristics with known species to identify it.
  2. Nomenclature: It is the process of naming organisms. Taxonomists use a standardized system called binomial nomenclature, which assigns each species a two-part Latin name consisting of the genus and species. For example, the human species is named Homo sapiens. This binomial system of classification was introduced by Carlous Linnaeus. He is also known as Father of Plant Taxonomy. This binomial system of classification was introduced by Carlous Linnaeus. He is also known as Father of Plant Taxonomy.
  3. Classification: Organizing organisms into hierarchical groups based on their similarities and differences. The main taxonomic ranks, from the broadest to the most specific, are Domain, Kingdom, Phylum, Class, Order, Family, Genus, and Species.

Systematics

Systematics is a broader field that encompasses taxonomy but extends beyond it to study the evolutionary relationships among organisms. It integrates data from various sources, including morphology, genetics, and biochemistry, to construct a comprehensive picture of life’s diversity and history. Systematics involves:

  1. Phylogenetics: The study of evolutionary relationships among species. Phylogenetic trees, or cladograms, visually represent these relationships, showing how different species are related through common ancestors.
  2. Evolutionary Biology: Systematics investigates the mechanisms of evolution and how genetic changes lead to the diversity of life. It examines patterns of descent and the processes that drive speciation.
  3. Comparative Studies: Systematic biologists compare characteristics across different organisms to understand their evolutionary history. This can include physical traits (morphology), genetic sequences (genomics), and biochemical pathways.

Importance of Taxonomy and Systematics

  • Biodiversity Conservation: By classifying and understanding the relationships among species, scientists can identify which species are at risk and develop strategies for their conservation.
  • Medicine and Agriculture: Knowing the classification and relationships of organisms helps in identifying sources of medicine, understanding pest species, and improving crop varieties.
  • Scientific Communication: A standardized classification system allows scientists worldwide to communicate accurately and efficiently about different species.
  • Understanding Evolution: Systematics provides insights into how life has evolved over time, revealing the patterns and processes that have shaped the diversity of life on Earth.

Modern Approaches

Advancements in technology, especially in genetics and molecular biology, have revolutionized taxonomy and systematics. DNA sequencing and molecular markers provide precise data on genetic similarities and differences, leading to more accurate classification and a deeper understanding of evolutionary relationships. This molecular approach often complements traditional methods based on physical characteristics.

Conclusion

Taxonomy and systematics are fundamental to the biological sciences, providing the framework for understanding the vast diversity of life. While taxonomy focuses on the classification and naming of organisms, systematics delves into their evolutionary relationships and histories. Together, they play a crucial role in biodiversity research, conservation efforts, and the broader field of biology.

Classification of living organisms

Classification of living organisms, also known as biological taxonomy, is the scientific process of categorizing and naming organisms based on their shared characteristics and evolutionary relationships. This system helps scientists and students understand the diversity of life, track how different species are related, and communicate more effectively about living organisms. Here’s an overview of the main concepts and categories in biological classification:

Levels of Classification

The classification system is hierarchical and includes several levels, each representing a more specific grouping of organisms. The main levels, from the broadest to the most specific, are:

  1. Domain: The highest level of classification, which groups organisms based on fundamental differences in their cell structure. There are three domains:

    • Archaea: Single-celled organisms without a nucleus, often found in extreme environments.
    • Bacteria: Single-celled organisms without a nucleus, with a wide range of habitats and functions.
    • Eukarya: Organisms with cells that have a nucleus, including plants, animals, fungi, and protists.
  2. Kingdom: Below the domain level, there are several kingdoms. For example, within the domain Eukarya, there are:

    • Animalia: Multicellular, eukaryotic organisms that are usually mobile and obtain food by consuming other organisms.
    • Plantae: Multicellular, eukaryotic organisms that typically produce their own food through photosynthesis.
    • Fungi: Eukaryotic organisms that absorb nutrients from organic matter.
    • Protista: A diverse group of eukaryotic organisms, which may be unicellular or multicellular, that do not fit into the other kingdoms.
  3. Phylum: Groups organisms based on major body plans or organizational patterns. For example, in the animal kingdom, Chordata is a phylum that includes animals with a spinal cord.

  4. Class: Divides phyla into groups based on more specific common characteristics. For example, Mammalia is a class within the phylum Chordata, including all mammals.

  5. Order: Further divides classes into groups. For instance, within Mammalia, Carnivora is an order that includes meat-eating mammals like lions and bears.

  6. Family: Groups organisms within an order that are even more closely related. For example, Felidae is the family that includes cats.

  7. Genus: A way to group species that are very closely related. For instance, Panthera is a genus that includes lions, tigers, and leopards.

  8. Species: The most specific level of classification, representing a single type of organism. A species is often defined as a group of individuals that can interbreed and produce fertile offspring. For example, Panthera leo is the species name for lions.

Binomial Nomenclature

Each species is given a unique two-part scientific name in Latin, called the binomial nomenclature. This name includes the genus and species. For example, in Homo sapiens, "Homo" is the genus, and "sapiens" is the species.

Importance of Classification

  • Organization: Helps organize the vast diversity of life into categories that are easier to study and understand.
  • Communication: Provides a universal language for scientists across the world.
  • Evolutionary Relationships: Shows how different organisms are related through evolution.
  • Identification: Aids in the identification and study of organisms.

Conclusion

The classification of living organisms is a foundational concept in biology that helps us make sense of the natural world. By understanding and using this system, students can better appreciate the complexity and interconnectedness of life on Earth.

Sunday, 26 May 2024

Biodiversity

Biodiversity is the variety of all living things on Earth. This includes different plants, animals, bacteria, and even fungi. Biodiversity can be found everywhere: in forests, oceans, deserts, and even in your backyard!

Why is Biodiversity Important?

  1. Ecosystem Health: Different species depend on each other. For example, bees pollinate flowers, which helps plants grow and produce food.
  2. Medicine: Many medicines come from plants and animals. For example, aspirin was originally made from the bark of willow trees.
  3. Food: We rely on different plants and animals for food. Imagine if we only had one type of fruit or vegetable to eat!

Examples of Biodiversity

  1. Rainforests: These are full of different species of trees, plants, insects, birds, and mammals. The Amazon rainforest is one of the most biodiverse places on Earth.

  2. Coral Reefs: These underwater ecosystems have thousands of species of fish, corals, and other marine life. The Great Barrier Reef in Australia is a famous example.

  3. Grasslands: These areas have a variety of grasses, flowers, insects, and animals like buffalo and zebras. The African savanna is a well-known grassland.

How Can We Protect Biodiversity?

  1. Conservation Areas: Creating parks and reserves to protect natural habitats.
  2. Sustainable Practices: Using resources like water, trees, and fish in ways that do not deplete them.
  3. Reducing Pollution: Keeping our air, water, and soil clean helps all living things.

Note:

1. Make a list of plants and animals that are found in and around your home. Observe the various kinds of plants and animals and how they play a role in your life and benefit your neighbors.

2. Make a list of the various food grains available in your kitchen and find out how they are useful in your diet.

Remember

For our daily needs, we have to consume different types of plants and animals' items. For oxygen we need plants. Water availability also depends on availability of plants. These are all comes from the available biodiversity. Therefore, biodiversity is essential for a healthy planet. Every species, no matter how small, has an important role to play in the web of life!

Tuesday, 21 May 2024

Compound microscope

 A compound light microscope is made up of two sets of lenses of which one is known as the objective and the other as eye piece. It is one of the most commonly used and suitable one in the biology laboratory. The different parts of a compound microscope are separated into two groups on the basis of their function-Mechanical parts and Optical parts.

1. Mechanical parts:

It includes (a) Foot, (b) Pillar, (c) Arm, (d) Stage, (e) Body tube, (f) Draw tube, (g) Coarse and fine adjustment screws and (h) Nose piece. A brief description of the different mechanical parts is given below-

(a) Base or foot: A basal V or horse shoe-shaped part on which the whole body of microscope stands.

(b) Pillar: It is a short vertical limb- like structure stands at right angle to the foot.

(c) Arm or handle: It is a sickle- shaped portion of the microscope. The lower portion of the arm stands on the pillar and upper portion connect the body tube. The point where the pillar and arm meet is called inclination joint. This is provided with a sliding screw on two sides of it, with the help of which the arm can be adjusted backward and forward as desired.

(d) Stage: A round or rectangular or square stage is attached to the top of the pillar and in front of the handle. There is a small hole at its centre. The stage is provided either with movable- sliding system or only spring clips on two sides of the hole. The former helps to hold the slide and permits forward, backward and sideways movement with the help of screw provided with the stage. The latter holds the slide firmly in one position.

(e) Sub-stage: A sub-stage is attached directly below the stage. It may be movable or fixed. It consists of mainly two parts- iris diaphragm and condenser lens. Iris diaphragm is a wheel- shaped metal disc which regulates the entry of light by changing its aperture. Condenser is a system of two or more lenses which receives parallel light rays from the mirror and converge them. Both the iris diaphragm and condenser lens are placed within the bangle-like metallic ring of the sub-stage.

(f) Body tube: It is composed of a tube and attached to the upper end of the arm by means of a short connective called the bridge. The body tube carries the draw tube and the ocular at its upper end. The lower end of the tube carries a revolving nose piece with about three objectives viz, low power, high power and oil immersion libroрмоэ и да подаризн

(g) Draw tube: This is a graduated small tube placed on the upper side of the body tube and partly remains inside the body tube.
(h) Coarse and fine adjustment screws: There are the two pairs of screws placed on the lateral sides of the bridge connecting the body tube and handle. The coarse pair is placed above the fine pair. With the help of coarse adjustment screw, the body tube can be moved up and down rapidly to bring the object into focus under low power. Fine adjustment screws are responsible for slow vertical movement of the body tube and is used when the object is under high power. (i) Nose piece: It is a circular disc-shaped structure, generally having three objective lenses screwed at different positions.

The draw tube, body tube and nose piece together constitute the mechanical tube. The length of the mechanical tube of all types of compound microscope is 160 mm. Mechanical tube, objective and eye piece constitute the optical tube through which light is traversed. The length of the optical tube is 180 mm.
2. Optical parts:

Mirror, condenser, objective and eye piece constitute the optical part. A brief description of the different parts is given below-

(a) Mirror: It is a plano-concave mirror, with one side plain and other concave. The plain side is used to reflect sunlight rays while concave is used for the rays from a lamp. A mirror focuses the light on the object through the condenser.

(b) Condenser: It is made of several plano-convex lenses and converges the beam of light focused by the mirror or artificial light. Below the condenser mechanical diaphragm is present only to control the entry of light.

(c) Objectives: It is the most important lens system of the microscope controlling both the available magnification and quality of the image. These lenses are attached to the nose piece. Usually there are two objectives, which provide magnification power of 10X and 45X. An oil
immersion objective (100X) is generally present in research type of microscope in addition to the above.

(d) Eye piece or ocular: Eye piece is a small tube provided with the plano-convex lenses at its two ends. It is attached to the top of the body tube. Eye pieces normally range in magnification from SX to 15X.

Magnifying power of a compound microscope:
Magnifying power of objective lens

Magnification of an object is equal to the magnifying power of an eye piece lens multiplied by the magnifying power of an objective lens. For example, if you are viewing an object through an eye piece lens of 10X and an objective lens of 10X, the object that you see under the microscope is magnified by 10x10 that is equal to 100 times.

Procedure for microscope operation:

Setting up of the microscope-

(a) When taking the microscope from its case, carry it with both hands. Hold the arm with one hand and place the other below the base to give support. Set the instrument down gently on the table, keeping the arm towards you, the stage away from you and the base several inches from the edge of the table.

(b) Rotate the nose piece until the low power objective (the shorter one) is in line with the body tube and clicks into position.

(c) If your microscope has a mirror instead of a sub-stage illuminator, you must look through the ocular and move the mirror around until it reflects light upward through the opening in the stage. Use the flat side of the mirror, not the concave side. Do not let sun-light strike the mirror directly.

(d) Open the iris diaphragm if the condenser is present. Look through the eye piece, adjust the mirror and diaphragm to get a complete and evenly brightly illuminated round field of vision.

(e) If the ocular or objective is cloudy or dusty, clean the lenses gently with a small piece of lens paper. Do not use any other kind of paper or cloth.

How to focus the microscope-

(a) A prepared slide is placed on the centre of the stage and fix it with clips.

(b) Now the low power objective is lowered down over the slide by rotating the coarse adjustment screw. While doing this, objective should be viewed from the side, so that the contact between the lens and the slide is avoided.

(c) Now while looking through the ocular, use the coarse adjustment to move the body tube upward or downward until the image becomes visible and sharp.

(d) When higher magnification is desired, first focus the object under the low power of the microscope and then rotate the nose piece until the high power objective (the longer one) is in lines with the body tube and clicks into position. Now with the help of fine adjustment move the body tube upward or downward to bring the image into the sharpest focus. While doing this, always look carefully so that the contact between the lens and the slide is avoided.

Study of simple microscope

The simple dissecting microscope is made up of a single lens which is used to view the object directly. It is úsed during the study of whole or part of an organism like taxonomical studies, embryo separation etc.

It is made up of the following parts-

(a) Base or foot: This is the U or V-shaped lowermost basal portion of the microscope on which the main body stands.

(b) Limb or pillar : This is a short vertical structure of the microscope which stands at the right angle to the foot.

(c) Draw tube: This is a short tube present above the limb and adjusted inside of it by rack and pinion arrange- ment.

(d) Adjustment screw : Two laterally placed adjustment screws are present at the junction of the limb and draw tube. The draw tube can be moved up and downward by adjusting the screw.

(e) Stage: A rectangular or square glass plate is attached at the top of the pillar and at right angle to it parallel to the foot. It is provided with two lateral clips placed in front of the draw tube.

(f) Folded arm: It is a flat and narrow metallic piece present at the apex of the draw tube and attached at the right angle to it. It moves horizontally.

(g) Eye piece: This is a short tube with a single convex lens attached to its upper end. The eye piece is placed within a metallic ring. The base of the metallic ring is attached to the tip of the folded arm by a screw. The magnification of eye pieces are of 5X, 10X or 20X.

(h) Mirror: A movable simple mirror is placed below the stage and attached to the front of pillar.

Setting and working of a dissecting microscope:

Microscope should be placed where light is sufficient. Then an object is placed at the centre of the stage on a clean slide. The lens is moved over the stage, fixed over the object and adjusted by tilting the folded part of the arm as desired. The object is then illuminated by suitably turning the mirror below and viewed properly by the vertical movement



Internation Day for Biodiversity 2024

সকলোতকৈ দৰকাৰী কিন্তু ৯০% ত কৈ অধিকলোকে আওকাণ কৰা কামটোৱেই হৈছে পৰিৱেশ বা জীৱ-জগতৰ প্ৰতি কৰা চৰ্চাৰ অনিহা। বিচিত্ৰ জীৱকূলে সমৃদ্ধি কৰি তোলা এই জীৱজগত লাহে লাহে মানুহৰ বাবে বিপৰ্য্যয়ৰ কাৰণ হৈ পৰিছে। মানুহৰ নিজৰ স্বাৰ্থ কাৰণে প্ৰকৃতিৰ পৰা সম্পদ আহৰণ কৰিবলৈ যাওঁতে জীৱকূলৰ ওপৰত ঋণাত্মক প্ৰভাৱ পৰিবলৈ ধৰিলে। সময়ৰ গতিত মানুহৰ জীৱন-প্ৰণালী উন্নত কৰিবলৈ যাওঁতে আমাৰ চৌপাশে থকা বিভিন্ন পশু-পখী, গছ-লতাৰ প্ৰতি কৰা আওকাণৰ বাবে আজি বহুতো জীৱ পৃথিৱীৰ পৰা বিলুপ্ত হ'ল বা বহুতো জীৱ বিলুপ্তিৰ পথত অগ্ৰসৰ হৈছে। জীৱজগতত বতি থকা এই জীৱকূলক ৰক্ষণাবেক্ষণ দিয়াৰ বাবে কম হলেও কিছুমান চৰকাৰী সংস্থাৰ উপৰিও বে-চৰকাৰী সংস্থা, প্ৰকৃতি কৰ্মী, অনুষ্ঠান- প্ৰতিষ্ঠানে কাম কৰি আছে। সেই কামৰ এটা এংশ হিচাপে প্ৰতি বছৰে ২২ মে তাৰিখে বিশ্বজুৰি আন্তৰাষ্ট্ৰীয় জৈৱ-বিচিত্ৰ দিৱস হিচাপে ১৯৯২ চনৰ পৰাএ পাতি আহিছে। ইয়াৰ উদ্দেশ্য হল সমাজৰ সকলো শ্ৰেণী মানুহৰ মাজত জৈৱ-বিচিত্ৰৰ উপকাৰিতা, ইয়াৰ ব্যৱহাৰ আৰু সংৰক্ষণৰ বিষয়ে সজাগ কৰি তোলা।  

Monday, 13 May 2024

Wildlife; Poaching, man-‐wildlife conflicts, Conservation and Mitigation

Wildlife:

Wildlife represents the rich tapestry of life on our planet, playing essential roles in ecosystems, biodiversity, and the health of our planet. However, wildlife faces numerous threats, including poaching, human-wildlife conflicts, habitat loss, and climate change. Conservation efforts are essential to safeguarding wildlife populations and ensuring their long-term survival. Understanding the complex dynamics of poaching, human-wildlife conflicts, and conservation strategies is crucial for mitigating these threats and promoting coexistence between humans and wildlife.

Poaching:

Poaching, the illegal hunting, capturing, and killing of wildlife for commercial gain or subsistence, poses a severe threat to many species worldwide. Poachers target iconic species such as elephants, rhinos, tigers, and pangolins for their tusks, horns, fur, and other body parts, driving many species to the brink of extinction. The illicit wildlife trade fuels organized crime, corruption, and instability, undermining conservation efforts and threatening biodiversity and ecosystem integrity. Combating poaching requires robust law enforcement, wildlife protection measures, community engagement, and international cooperation to disrupt illicit supply chains, dismantle trafficking networks, and prosecute offenders.

Human-Wildlife Conflicts:

Human-wildlife conflicts arise when wildlife encroaches on human settlements, agriculture, and infrastructure, leading to property damage, livestock predation, crop raiding, and human injuries or fatalities. Rapid urbanization, habitat fragmentation, and expansion of agricultural lands into wildlife habitats exacerbate conflicts between humans and wildlife, particularly in areas where people rely on natural resources for their livelihoods. Addressing human-wildlife conflicts requires integrated approaches that combine community-based conservation, land-use planning, conflict mitigation measures, and compensation schemes to promote coexistence, reduce conflict risk, and enhance human and wildlife well-being.

Conservation and Mitigation:

Conservation efforts aim to protect and restore wildlife habitats, conserve endangered species, and promote sustainable use of natural resources to ensure the long-term viability of ecosystems and biodiversity. Conservation strategies include protected area management, habitat restoration, species reintroduction, captive breeding programs, wildlife corridors, and community-based conservation initiatives that engage local communities in conservation efforts and promote sustainable livelihoods. Mitigating human impacts on wildlife also involves reducing habitat destruction, pollution, overexploitation, and climate change through sustainable development practices, environmental education, and policy interventions that promote conservation stewardship, resilience, and biodiversity conservation.

Conclusion:

Wildlife conservation is a shared responsibility that requires collective action, collaboration, and commitment from governments, communities, conservation organizations, and individuals worldwide. By addressing the root causes of poaching, human-wildlife conflicts, and habitat degradation, we can protect wildlife populations, preserve biodiversity, and ensure the health and integrity of ecosystems for future generations. Promoting coexistence between humans and wildlife is not only essential for conservation but also for fostering sustainable development, social equity, and harmony between people and nature. Together, we can build a future where wildlife thrives, ecosystems flourish, and humans coexist in harmony with the natural world.

দুখীয়া মানুহৰ প্ৰভু জুবিন গাৰ্গ

মই স্বাথৰ্পৰ হ'ব পাৰিলোঁহেঁতেন। বোম্বেত থাকি, পইচা ঘটি ঢেৰ গান গাই নাম কৰিব পাৰিলোঁহেঁতেন। কিন্তু মোৰ অসমৰ জনগণৰ প্ৰতি এটা দায়িত্ব আছে। ...