MCQ’s
Notes with Exercise
Class 11th Biology Chapter 7, The Kingdom Protists, covers a diverse group of eukaryotic organisms that don’t fit into the other kingdoms like plants, animals, or fungi. Here’s a general overview of the key points:
- Characteristics of Protists:
- Eukaryotic Organisms: Protists are eukaryotes, meaning they have membrane-bound organelles, including a nucleus.
- Diversity: Protists exhibit a wide range of characteristics, making them difficult to classify. They can be unicellular or multicellular, autotrophic (like plants) or heterotrophic (like animals), and live in various environments, especially aquatic ones.
- Classification of Protists:
- Animal-like Protists (Protozoa): These are heterotrophic protists that move and consume food. Examples include amoeba (moves using pseudopodia), paramecium (uses cilia for movement), and plasmodium (causes malaria).
- Plant-like Protists (Algae): These protists are autotrophic and perform photosynthesis. Examples include diatoms, dinoflagellates, and various types of algae (green, red, brown).
- Fungus-like Protists: These include slime molds and water molds, which decompose organic material like fungi.
- Reproduction in Protists:
- Asexual Reproduction: Protists commonly reproduce asexually through binary fission or multiple fission.
- Sexual Reproduction: Some protists, like algae, can also reproduce sexually, involving gametes and fertilization.
- Movement:
- Protists have various methods of movement, such as using cilia (hair-like structures), flagella (tail-like structures), or pseudopodia (temporary projections of the cell membrane).
- Role of Protists in the Environment:
- Photosynthesis: Plant-like protists contribute significantly to oxygen production and form the basis of aquatic food chains.
- Decomposition: Fungus-like protists help break down dead organic matter.
- Symbiotic Relationships: Some protists live in mutualistic relationships, while others, like certain protozoa, can be parasitic and cause diseases.
- Diseases Caused by Protists:
- Some protists are pathogens that cause diseases, such as malaria (caused by Plasmodium), sleeping sickness (caused by Trypanosoma), and amoebic dysentery (caused by Entamoeba).
This chapter highlights the diversity of protists, their classification, and their ecological roles, along with their impact on human health.