1. Option A, Blue green algae, acts as a bio-fertilizer for the rice crop. Blue-green algae, also known as cyanobacteria, establish a symbiotic relationship with rice plants, providing them with fixed atmospheric nitrogen. This process, known as nitrogen fixation, enhances soil fertility by increasingRead more

    Option A, Blue green algae, acts as a bio-fertilizer for the rice crop. Blue-green algae, also known as cyanobacteria, establish a symbiotic relationship with rice plants, providing them with fixed atmospheric nitrogen. This process, known as nitrogen fixation, enhances soil fertility by increasing the availability of nitrogen to the rice plants. The nitrogen-fixing ability of blue-green algae reduces the need for synthetic fertilizers, thereby promoting sustainable agricultural practices. Rhizobium species (Option B) typically form symbiotic relationships with leguminous plants, aiding in nitrogen fixation in their root nodules. Mycelium (Option C) refers to the vegetative part of fungi and does not directly act as a bio-fertilizer for rice crops. Azotobacter (Option D) is a free-living nitrogen-fixing bacterium that can enhance soil fertility but is not commonly associated with rice cultivation as blue-green algae are.

    See less
    • 5
  2. Option C, Chlorella, is the unicellular algae used to control the supply of oxygen in space programs. Chlorella's rapid growth rate and high oxygen production make it invaluable for maintaining oxygen levels in closed environments like spacecraft during space missions. Its photosynthetic activity efRead more

    Option C, Chlorella, is the unicellular algae used to control the supply of oxygen in space programs. Chlorella’s rapid growth rate and high oxygen production make it invaluable for maintaining oxygen levels in closed environments like spacecraft during space missions. Its photosynthetic activity efficiently converts carbon dioxide into oxygen, ensuring a sustainable oxygen supply for astronauts. Eulothrix (Option A), Spirogyra (Option B), and Oedogonium (Option D) are not typically utilized in space programs for oxygen production.

    See less
    • 5
  3. The red color of the Red Sea is due to the presence of Option B, algae. Trichodesmium erythraeum, a type of cyanobacteria, is primarily responsible for this phenomenon. These organisms contain pigments such as phycoerythrin, which impart a reddish hue to the water when they bloom in large quantitiesRead more

    The red color of the Red Sea is due to the presence of Option B, algae. Trichodesmium erythraeum, a type of cyanobacteria, is primarily responsible for this phenomenon. These organisms contain pigments such as phycoerythrin, which impart a reddish hue to the water when they bloom in large quantities. This occurrence is often referred to as a “red tide” or “sea sawdust” and can result in significant changes to the marine ecosystem. While other factors such as mineral sediments and dissolved organic matter can contribute to the sea’s coloration, the predominant cause of the Red Sea’s red coloration is the proliferation of these algae. Moss (Option A), fungus (Option C), and bacteria (Option D) are not typically associated with causing the red coloration observed in the Red Sea.

    See less
    • 5
  4. Agar-agar is obtained from Option C, algae. It is extracted from the cell walls of certain species of red algae, including Gelidium, Gracilaria, and Pterocladia. These algae are harvested, washed, and then processed to extract the agar, which is a gelatinous substance primarily composed of polysacchRead more

    Agar-agar is obtained from Option C, algae. It is extracted from the cell walls of certain species of red algae, including Gelidium, Gracilaria, and Pterocladia. These algae are harvested, washed, and then processed to extract the agar, which is a gelatinous substance primarily composed of polysaccharides. Agar-agar has a wide range of applications, including its use as a gelling agent in food preparation, particularly in desserts and confectionery. It is also utilized in microbiology as a solidifying agent for culture media, providing a stable surface for microbial growth. Due to its versatility, agar-agar has become an essential ingredient in various industries, including pharmaceuticals, cosmetics, and biotechnology. Its ability to form a stable gel at relatively low concentrations, along with its lack of flavor and odor, makes it highly desirable for use in numerous applications across different fields.

    See less
    • 5
  5. The cell wall of fungi is primarily composed of Option [D], chitin and hemicellulose. Chitin, a strong polysaccharide, forms the major structural component, providing rigidity and support to fungal cells. Hemicellulose, another polysaccharide, contributes to the strength and flexibility of the cellRead more

    The cell wall of fungi is primarily composed of Option [D], chitin and hemicellulose. Chitin, a strong polysaccharide, forms the major structural component, providing rigidity and support to fungal cells. Hemicellulose, another polysaccharide, contributes to the strength and flexibility of the cell wall. This unique composition distinguishes fungal cell walls from those of other organisms. Unlike plant cell walls, which contain cellulose, and bacterial cell walls, which contain peptidoglycan or other substances, fungal cell walls are characterized by the presence of chitin. This structural framework plays crucial roles in maintaining cell shape, protecting against environmental stresses, and facilitating nutrient uptake. Additionally, the composition of fungal cell walls influences interactions with other organisms and environmental factors, contributing to their ecological roles and impact on various ecosystems. Overall, chitin and hemicellulose are key components that define the distinctive architecture and function of fungal cell walls.

    See less
    • 4