Introduction:
When it comes to revising Zoology, there are two popular options available - online video lectures and textbooks. Both methods have their advantages and disadvantages, and the choice depends on personal preferences and learning style. In this response, we will explore the pros and cons of each option to help you make an informed decision.

Online Video Lectures:

1. Visual and Auditory Learning: Online video lectures provide a visual and auditory learning experience, making it easier to understand complex concepts. The use of visuals, diagrams, and animations can enhance the learning process and help in retaining information.

2. Interactive Learning: Many online video lectures offer interactive features like quizzes, assessments, and discussion forums. These features facilitate active learning and engagement with the subject matter, allowing you to test your knowledge and clarify doubts.

3. Convenience and Flexibility: Online video lectures can be accessed anytime and anywhere with an internet connection. This flexibility allows you to revise at your own pace and convenience, making it suitable for individuals with busy schedules.

4. Expert Instruction: Online video lectures are often conducted by subject matter experts who have in-depth knowledge of Zoology. Their expertise and experience can provide valuable insights and explanations, ensuring that you receive accurate and reliable information.

Textbooks:

1. Comprehensive Coverage: Textbooks provide comprehensive coverage of the subject matter, offering detailed explanations and examples. They are structured in a logical manner, allowing you to progress from basic to advanced concepts at your own pace.

2. Self-paced Learning: Textbooks allow you to learn at your own pace and revisit topics as needed. You have the freedom to spend more time on difficult concepts and skim through familiar topics, providing a personalized learning experience.

3. Enhanced Comprehension: Reading textbooks can improve reading and comprehension skills. It enables you to analyze and interpret information, enhancing your critical thinking abilities. Textbooks also provide the opportunity to take notes, annotate, and highlight important points for future reference.

4. Cost-effective: Textbooks are usually more cost-effective compared to online video lectures. They can be purchased or borrowed from libraries, making them accessible to a wider audience.

Conclusion:
Both online video lectures and textbooks have their merits and can be effective for revising Zoology. It is recommended to use a combination of both methods to maximize learning outcomes. Online video lectures can provide visual and interactive learning, while textbooks offer comprehensive coverage and self-paced learning. Choose the method that aligns with your learning style and preferences, and ensure to supplement your revision with practice questions and exercises to reinforce your understanding of the subject matter.