Invasive Species When Introduced Species Cause Harm
Duration: 4 min
This video lesson is available to enrolled students.
Inside: a video lesson and guided study material.
Module outline
- About the Course: About the Course
- Section 1 | भाषा (हिंदी) / Language (Hindi): भाषा, लिपि और वर्ण, वर्तनी, वर्ण-विन्यास, अनुस्वार, अनुनासिक, चंद्रबिंदु और ‘र’ के रूप, शब्द, पद और शब्द-भेद, संज्ञा और सर्वनाम, पद-भेद और रूप-विकार, लिंग, वचन, पुरुष और कारक, काल, वाच्य, वाक्य और वाक्य-भेद, संधि, समास, विलोम शब्द, पर्यायवाची शब्द, सामान्य अशुद्धियाँ, अनेक शब्दों के लिए एक शब्द, शब्द-भंडार, अपठित बोध, बहुविषयक सामग्री (विभिन्न अवधारणाओं से संबंधित सामग्री), वर्णमाला
- Section 1 | اردو زبان / Language (Urdu) — 22 Questions (Fixed): رسم الخط، حروفِ تہجی اور املا, اسم، ضمیر اور صفت, الفاظ، محاورے اور ضرب الامثال, تفہیمِ عبارت، انشا اور ترجمہ, تفہیم
- Section 1 | বাংলা ভাষা / Language (Bengali) — 22 Questions (Fixed): শব্দার্থ, বাগধারা ও ভাষাশুদ্ধি, বাক্য ও বাচ্য, শব্দগঠন ও শব্দভান্ডার, অনুবাদ, বোধপরীক্ষণ ও রচনা
- Section 1 | Language (English): Vocabulary, Noun, Subject Verb Agreement (Verb Noun Agreement), Adjectives, Verbs and Tenses, Pronoun, Verb, Adverb, Prepositions and Conjunctions, Parts of Speech, Determiner, Conjunction, Modals, Transformation of Sentences, Direct and Indirect Speech, Sentence Correction (Error Correction), Sentence Completion (Fill in the blanks), Sentence Construction, Sentence Structure and Common Errors, Reading Comprehension, Cloze Test (Cloze Passage), Verbal Analogy (Word Based Analogy), Facts, Inference and Judgements
- Section 2 | Primary Maths & Reasoning / प्राथमिक गणित एवं तर्कशक्ति: Ratio and Proportion / अनुपात और समानुपात, Divisibility Rules / विभाज्यता के नियम, Mixture and Alligation / मिश्रण और एलिगेशन, Permutation and Combination / क्रमचय और संचय, Number System / संख्या पद्धति, HCF and LCM / महत्तम समापवर्तक और लघुत्तम समापवर्त्य, Sequences, Series and Combinatorics / अनुक्रम, श्रेणी और संयोजन, Time, Speed and Distance / समय, चाल और दूरी, Series / श्रेणी, Coding-Decoding / कूट लेखन एवं कूट वाचन, Non-Verbal Reasoning / अशाब्दिक तर्क, Percentage / प्रतिशत, Average / औसत, Profit, Loss and Discount / लाभ, हानि और बट्टा, Simple and Compound Interest / साधारण और चक्रवृद्धि ब्याज, Time and Work / समय और कार्य, Solid Mensuration / घन क्षेत्रमिति, Age Problems / आयु संबंधी प्रश्न, Arithmetic / अंकगणित, Simplification, Indices and Surds / सरलीकरण, घातांक और करणी, Algebra / बीजगणित, Probability / प्रायिकता, Trigonometry / त्रिकोणमिति, Syllogisms / न्यायवाक्य, Seating Arrangement and Puzzles / बैठक व्यवस्था एवं पहेलियाँ, Blood Relations / रक्त संबंध, Direction and Distance / दिशा एवं दूरी, Analytical Reasoning (Counting Figures Reasoning) / विश्लेषणात्मक तर्क (आकृति गणना तर्क), Mathematical Operations and Missing Numbers / गणितीय संक्रियाएँ एवं लुप्त संख्या, Calendar and Clock / कैलेंडर एवं घड़ी, Clock / घड़ी, Cubes, Dice and Figure Counting / घन, पासा एवं आकृतियों की गिनती, Venn Diagrams, Syllogism and Inequalities / वेन आरेख, न्याय वाक्य एवं असमानता, Data Arrangement / आँकड़ों की व्यवस्था, Inequality / असमानता, Analogy and Classification / सादृश्यता एवं वर्गीकरण, Order and Ranking / क्रम एवं रैंकिंग, Sets, Relations, Functions and Discrete Mathematics / समुच्चय, संबंध, फलन और विविक्त गणित, Number Systems and Number Theory / संख्या पद्धति और संख्या सिद्धांत, Coordinate Geometry, Vectors and 3D Geometry / निर्देशांक ज्यामिति, सदिश और त्रिविमीय ज्यामिति, Polynomials, Equations and Complex Numbers / बहुपद, समीकरण और सम्मिश्र संख्याएँ
- Section 2 | General Awareness (GK + Current Affairs) / सामान्य जागरूकता (GK + समसामयिकी): Polity / राजव्यवस्था, Scientific Achievements and Research / वैज्ञानिक उपलब्धियाँ और अनुसंधान, Biology / जीव विज्ञान, State-Specific General Knowledge / राज्य विशेष सामान्य ज्ञान, Chemistry / रसायन विज्ञान, History / इतिहास, Geography / भूगोल, Indian Economy / भारतीय अर्थव्यवस्था, Environment / पर्यावरण, Current Affairs / समसामयिकी, Static General Knowledge / स्थैतिक सामान्य ज्ञान
- Section 3 | Computer System and Org. (CSO): Basics of COA, Floating Point Rep, Cache Memory Organization, Instr Formats & Modes, Programming the Basic Computer, Input Output Organisation, Register Transfer and Microoperations, Control Unit Design
- Section 3 | Database Management System: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, SQL, File Organization & Indexing, Relational Algebra, Relational Calculus, Transaction Management, Concurrency Control
- Section 3 | Operating System: Introduction to OS, Process Management, CPU Scheduling, Threads & Process Creation, Memory Management, Virtual Memory, Disc Scheduling, File Management, Process Synchronization
- Section 3 | Computer Networks: Introduction to CN, Data Communication, DLL: Access Control, DLL: Flow Control, DLL: Error Control, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Transport Layer Services, TL: Congestion & UDP, Application Layer, Hardware basics
- Section 3 | Data Structures: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing, Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Minimum Spanning Trees, Shortest Path Algos
- Section 3 | Theory Of Computation & Compiler Design: Introduction to TOC, Deterministic FA (DFA), Non-Deterministic FA, Regular Expressions, Grammar, Regular Language Properties, Moore & Mealy Machines, Pushdown Automata & CFG, Turing Machines, Intro to Compilers, Lexical Analysis, Grammar & CFG, Syntax Analysis: Top-Down, Syntax Analysis: Bottom-Up, Semantic Analysis & SDT, Intermediate Code Gen, Code Optimization
- Section 3 | Emerging Trends (AI, Societal Ethics & MS Office): Computer Fundamentals, Emerging Tech Trends, Society, Law & Ethics, MS Office Applications, Trade, Marketing and Consumer Protection / व्यापार, विपणन एवं उपभोक्ता संरक्षण, Cyber Safety and Security, Computer Software, Operating System, Computer Networks, Word Processing (MS Word), Terms & Abbreviations, Presentation Software (MS PowerPoint), Internet of Things, Cloud Computing
- Section 3 | Software Engineering: Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Maintenance and Configuration Management, Software Testing
- Section 3 | C Programming: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling
- Section 3 | OOPS, C++, JAVA, HTML: OOPS with C++, Java, HTML Basics, CSS
- Section 3 | Java: Java Fundamentals, Array, String, IO & References, OOPS with Java
- Section 3 | Python: Introduction to Python, Tokens, Variables, Data Types, I/O, Operators & Expressions, Control Flow & Looping, Collections & Strings, Functions & Modules, File Handling & Data Analysis
- Section 3 | Digital Electronics: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation
- Section 3 | Multimedia: Multimedia
- BPSC Previous Year Papers:
AI summary & chapters
AI Summary
An AI-generated summary of this video lecture.
This short bilingual lesson introduces invasive species as alien species that cause harm to biodiversity after human-mediated introduction. The main slide defines an alien species as one occurring outside its natural range due to human introduction, and states that it becomes invasive when its establishment or spread threatens biodiversity. A key distinction is emphasized: not every introduced species becomes invasive. The right-side diagram links human transport modes—cargo ship, airplane, globe—to flowering plants and fish, with red arrows showing the pathway of introduction and impact. Important points list Indian examples such as Parthenium, Lantana, and water hyacinth, and note that African catfish threatens native Indian fishes. A global example is the introduced Nile perch, which harmed Lake Victoria’s native cichlid fishes. Later, the lesson shifts to a multiple-choice question asking students to identify the aquatic weed nicknamed “Terror of Bengal.” The correct answer is B, Eichhornia crassipes—Water hyacinth. The explanation notes that dense growth of water hyacinth can cover the water surface and disturb aquatic life. The instructor is visible in a small corner window, but the instructional content is carried mainly by the static bilingual slide, definitions, examples, and the quiz question.
Chapters
0:00 – 2:00 00:00-02:00
The opening slide is titled “Invasive Species: When Introduced Species Cause Harm” with a Hindi subtitle. The core definition appears on screen: “An alien species occurs outside its natural range because of human introduction,” followed by “It becomes invasive when its establishment or spread threatens biodiversity.” A cautionary point is shown: “Not every introduced species becomes invasive.” The right-side illustration depicts a cargo ship, airplane, globe, flowering plants, and fish connected by red arrows, visually representing human-mediated transport and ecological impact. The “Important Points” list includes Indian examples—Parthenium, Lantana, and water hyacinth—and states that “African catfish threatens native Indian fishes.” A global example is also given: “Introduced Nile perch harmed Lake Victoria’s native cichlid fishes.” Red underlines and a hand-drawn line connect the term “alien species” to the fish illustration, reinforcing the definition.
2:00 – 3:52 02:00-03:52
The lesson continues with the same bilingual slide and then introduces a multiple-choice question: “Identify the aquatic weed nicknamed ‘Terror of Bengal.’” The correct answer is revealed as “B. Eichhornia crassipes — Water hyacinth.” The on-screen explanation states that “Dense growth can cover the water surface and disturb aquatic life,” linking the species to its ecological impact. The “Important Points” list remains visible, reiterating examples such as Parthenium, Lantana, and water hyacinth, and the threat posed by African catfish to native Indian fishes. The diagram of transport and species introduction remains on the right side, maintaining the visual context for how invasive species are introduced and spread.
The central teaching point is the distinction between introduced and invasive species: an alien species is one that occurs outside its natural range due to human introduction, but it only becomes invasive when its establishment or spread threatens biodiversity. The lesson uses a bilingual slide with clear definitions, a visual diagram of human transport pathways, and specific examples to make the concept concrete. Indian examples include Parthenium, Lantana, water hyacinth, and African catfish, while a global example is the Nile perch in Lake Victoria. The quiz question on the “Terror of Bengal” reinforces recognition of water hyacinth (Eichhornia crassipes) as a harmful aquatic invasive species whose dense surface growth disrupts aquatic ecosystems. The progression moves from definition to examples to application through a multiple-choice question, supporting exam-style recall of key terms and species names.

