1.
Microorganisms that float near the surface of the water and provide food for larger organisms
Correct Answer
C. Plankton
Explanation
Plankton are microorganisms that float near the surface of the water and serve as a food source for larger organisms. They include a wide range of organisms such as bacteria, algae, and small animals. Plankton play a crucial role in aquatic ecosystems as they form the base of the food chain, providing nutrients for higher trophic levels. Therefore, the answer "Plankton" accurately describes the microorganisms that fulfill this role in the water.
2.
The volvox is one example of
Correct Answer
A. Green algae
Explanation
The correct answer is green algae because Volvox is a genus of green algae that forms spherical colonies. These colonies are composed of numerous individual cells that are interconnected and work together to perform various functions. Volvox is commonly found in freshwater environments and is known for its unique reproductive system and ability to photosynthesize. It is not a type of yellow, red, or blue algae, which are different groups of algae with distinct characteristics and pigments.
3.
The largest of the brown algae
Correct Answer
D. Kelps
Explanation
Kelps are the largest of the brown algae. Brown algae are a type of seaweed that can be found in marine environments. Kelps are known for their large size and complex structures, which can form dense underwater forests. They are typically found in colder waters and can grow to be several meters long. Kelps are important ecologically as they provide habitat and food for a variety of marine organisms.
4.
Generally classified as bacteria
Correct Answer
C. Blue-green algae
Explanation
Blue-green algae, also known as cyanobacteria, are a group of photosynthetic bacteria that are classified as algae due to their ability to perform photosynthesis. They are called blue-green algae because they often have a bluish-green color, which is a result of the pigments they contain. Despite being classified as bacteria, they share characteristics with algae, such as their ability to produce oxygen through photosynthesis. Blue-green algae are found in various environments, including freshwater and marine habitats, and they play an important role in the ecosystem as primary producers.
5.
Organisms that produce red tides:
Correct Answer
B. Dinoflagellates
Explanation
Dinoflagellates are organisms that are known to produce red tides. Red tides are caused by an overgrowth or bloom of these microscopic algae in the water, leading to the water appearing red or brown in color. These dinoflagellates release toxins that can be harmful to other marine organisms and can even cause respiratory issues in humans. Therefore, the presence of dinoflagellates is closely monitored as they can have detrimental effects on marine ecosystems and human health.
6.
Organisms that obtain their nutrition from dead organisms:
Correct Answer
B. SapropHytes
Explanation
Saprophytes are organisms that obtain their nutrition from dead organisms. They decompose and absorb nutrients from dead organic matter, helping in the recycling of nutrients in ecosystems. They play a crucial role in breaking down dead plants, animals, and other organic material, releasing essential nutrients back into the environment. This process is important for maintaining the balance of nutrients and energy flow in ecosystems.
7.
Organisms that manufacture its own food:
Correct Answer
C. AutotropHs
Explanation
Autotrophs are organisms that are capable of manufacturing their own food through the process of photosynthesis or chemosynthesis. They can convert sunlight or inorganic compounds into organic molecules, such as glucose, which serves as their source of energy. Autotrophs are commonly found in the plant kingdom, where they possess specialized structures like chloroplasts that enable them to carry out photosynthesis. Unlike autotrophs, heterotrophs rely on consuming other organisms for their energy needs. Scavengers and saprophytes are types of heterotrophs that obtain their food by feeding on dead organic matter.
8.
Organisms that must obtain their food from sources outside themselves:
Correct Answer
D. HeterotropHs
Explanation
Heterotrophs are organisms that cannot produce their own food and must obtain it from external sources. Unlike autotrophs, which can synthesize organic compounds from inorganic substances, heterotrophs rely on consuming other organisms or organic matter for their energy and nutrients. Scavengers and saprophytes are specific types of heterotrophs that obtain their food from dead or decaying organic material. Therefore, heterotrophs is the correct answer in this context.
9.
Example of the yellow algae:
Correct Answer
A. Diatoms
Explanation
Diatoms are an example of yellow algae because they are a type of algae that typically have a yellowish-brown color. They are single-celled organisms that have a unique cell wall made of silica, giving them a distinct appearance. Diatoms are photosynthetic and are found in various aquatic environments, including freshwater and marine habitats. They play a crucial role in the ecosystem as primary producers, contributing to the food chain and oxygen production.
10.
Edible algae cultivated by the Japanese:
Correct Answer
D. Nori
Explanation
Nori is the correct answer because it is a type of edible algae that is commonly cultivated by the Japanese. It is used in many traditional Japanese dishes, especially sushi, as it provides a unique flavor and texture. Nori is rich in vitamins and minerals, making it a nutritious addition to meals. Its cultivation and consumption have a long history in Japan and it continues to be a popular ingredient in Japanese cuisine.