Free Biodiversity and Variety of Life MCQs with Answers

2871. Algae are:

• A. Unicellular organisms only
• B. Filamentous organisms only
• C. Huge multicellular organisms only
• D. Simple Acellular organisms
• E. Ranges from unicellular to Filaments to huge multicellular organisms

Explanation: Algae can be unicellular (existing as individual cells), colonial (several to many cells living in a colony), filamentous (several to many cells forming a chain or filament) or multicellular (usually macroscopic with several to many layers of cells).

2872. Plasmodium, the apicomplexan that causes malaria, enters the human bloodstream through the bite of which parasitic protozoan?

• A. Amoeba
• B. Radiolarians
• C. Forams
• D. Female Anopheles mosquito

Explanation: The female Anopheles mosquito is the correct answer because it acts as the vector for Plasmodium, the parasite that causes malaria. When the mosquito bites a human, it transmits the parasite into the bloodstream. The other options, Amoeba, Radiolarians, and Forams, are different types of protists that do not play a role in malaria transmission. Amoebas are known for causing diseases like amoebic dysentery, while Radiolarians and Forams are primarily marine organisms with no connection to malaria.

2873. What is the nature of the plasmodium in slime molds?

• A. Uninucleated
• B. Enucleate
• C. Mononucleated
• D. Multinucleated

Explanation: The plasmodium of slime molds is an amoeboid mass of cytoplasm that is multinucleated, meaning it contains many nuclei within a single cell mass. This structure allows the slime mold to move and ingest food particles efficiently. The other options are incorrect: 'Uninucleated' and 'Mononucleated' imply only one nucleus, which is not the case with slime mold plasmodium. 'Enucleate' means lacking a nucleus, which is also incorrect as slime molds are defined by their multiple nuclei.

2874. What are the characteristics of Euglena?

• A. Exhibit solely animal-like characteristics
• B. Exhibit solely plant-like characteristics
• C. Exhibit both animal and plant-like characteristics
• D. Exhibit characteristics typical of bacteria
• E. Exhibit characteristics typical of viruses

Explanation: Euglena is a protist that uniquely combines traits of both plants and animals. It contains chloroplasts, enabling it to perform photosynthesis like a plant. However, it also moves like an animal using a whip-like flagellum. This dual characteristic allows Euglena to adapt to different environments by switching between autotrophic and heterotrophic modes of nutrition. Options A and B are incorrect because they suggest Euglena exhibits only one type of characteristic. Option D and E are incorrect as they imply Euglena shares traits with bacteria or viruses, which it does not.

2875. What category do slime molds belong to?

• A. Animal-like Protist
• B. Bacteria-like Protist
• C. Plant-like Protist
• D. Virus-like Protist
• E. Fungi-like Protist

Explanation: Slime molds are classified as fungi-like protists because they share some characteristics with fungi, such as the production of spores and a similar growth form in certain life stages. However, unlike true fungi, they exhibit a unique life cycle that includes both unicellular and multicellular stages. The other options are incorrect because slime molds do not exhibit the defining characteristics of animals, bacteria, plants, or viruses. Animal-like protists typically have motility and ingestion of food, which slime molds do not. Bacteria-like and virus-like categorizations are inaccurate as slime molds are eukaryotic and complex compared to bacteria and viruses. Plant-like protists are primarily photosynthetic, a trait slime molds lack.

2876. Sporozoans have:

• A. Both locomotory organelles and contractile vacuoles
• B. Locomotory organelles but not contractile vacuoles
• C. Contractile vacuoles but not locomotory organelles
• D. Neither locomotory organelle nor contractile vacuoles
• E. All are incorrect

Explanation: Sporozoans are a group of protists that are adapted to a parasitic lifestyle. They lack traditional locomotory organelles such as flagella or cilia, which are not necessary for their parasitic mode of life. Additionally, they do not have contractile vacuoles since they rely on their host for osmoregulation. Option D is correct as it accurately reflects these characteristics. The other options incorrectly attribute sporozoans with features they do not possess.

2877. Asexual cycle of Plasmodium in man comprises of phases [In order]:

• A. Erythrocytic phase ⟶ Pre-erythrocytic phase ⟶ Gamogony ⟶ Post-erythrocytic phase
• B. Erythrocytic phase ⟶ Gamogony ⟶ Pre-erythrocytic phase ⟶ Post-erythrocytic phase
• C. Pre-erythrocytic phase ⟶ Post-erythrocytic phase ⟶ Gamogony ⟶ Erythrocytic phase
• D. Post-erythrocytic phase ⟶ Pre-erythrocytic phase ⟶ Erythrocytic phase ⟶ Gamogony
• E. Pre-erythrocytic phase ⟶ Erythrocytic phase ⟶ Post-erythrocytic phase ⟶ Gamogony

Explanation: The Plasmodium life cycle in humans starts with the pre-erythrocytic phase, where sporozoites infect liver cells and multiply. It is followed by the erythrocytic phase, characterized by the infection and destruction of red blood cells, causing malaria symptoms. The post-erythrocytic phase entails further development in the blood. Finally, gamogony occurs, where gametocytes form, ready for transmission to a mosquito. Options A, B, C, and D present incorrect sequences that do not correspond to the actual life cycle of Plasmodium in humans.

2878. In the Gametogony stage of the sexual cycle male gametocyte forms:

• A. 6 - 8 sperm-like microgametes
• B. 6 - 8 sperm-like macrogametes
• C. 8 - 12 sperm-like microgametes
• D. 5 - 7 sperm-like macrogametes
• E. 12 - 15 sperm-like microgametes

Explanation: During the gametogony stage of the sexual cycle in certain protists, male gametocytes produce several flagellated microgametes, which are sperm-like in structure. These microgametes are essential for fertilization, as they fuse with the larger, non-motile female macrogametes to form a zygote. The correct number of microgametes typically produced is between 6 and 8. Options suggesting macrogametes or incorrect ranges of microgametes are inaccurate as they do not align with the typical biological processes observed in these organisms.

2879. Concerning conditions necessary for the production of water molds, which statement is correct?

• A. 50% relative humidity is essential for sporangia production
• B. Sporangia cannot be produced if relative humidity exceeds 70%
• C. Sporangia are typically produced in a fully saturated atmosphere at temperatures between 25°C - 37°C
• D. The optimum temperature for producing sporangia is around 21°C
• E. Sporangia never form in their preferred environmental conditions

Explanation: The correct answer is Option D: 'The optimum temperature for the production of sporangia is 21°C'. Water molds, or oomycetes, have specific environmental preferences for sporangia production, and 21°C is often suitable for some species. Option A is incorrect as 50% humidity is not a universal requirement. Option B is incorrect because high humidity usually favors sporangia production. Option C is not universally applicable, as the temperature range is too broad and not specific to all water molds. Option E is incorrect because sporangia do produce under optimal conditions specific to their environmental needs.

2880. Balantidium & Opalina are included in class:

• A. Flagellata
• B. Sarcodina
• C. Sporozoa
• D. Ciliata
• E. Suctoria

Explanation: The correct answer is Ciliata. Balantidium and Opalina are ciliated protozoans, meaning they use cilia for movement and feeding, which is a defining characteristic of the class Ciliata. This distinguishes them from other classes of protozoans like Flagellata, which use flagella; Sarcodina, which use pseudopodia; Sporozoa, which are mostly non-motile; and Suctoria, which use tentacle-like structures instead of cilia in their feeding process.