Kuis 2 Mikrobiologi Fungi, Algae, Protozoa

A mycotoxin is indeed a toxic substance that is produced by a fungus. Fungi can produce various types of mycotoxins, which can contaminate food and feed crops. These mycotoxins can have harmful effects on human and animal health, causing illnesses and even death. Therefore, it is important to be aware of mycotoxin contamination and take measures to prevent its occurrence in order to ensure food safety.

Protozoa are indeed usually motile, eukaryotic unicellular microorganisms. They have the ability to move using structures such as cilia, flagella, or pseudopodia. They are also eukaryotic, meaning they have a true nucleus and other membrane-bound organelles within their cells. Being unicellular means that they are composed of a single cell, unlike multicellular organisms. Therefore, the statement "Protozoa are usually motile, eukaryotic unicellular microorganisms" is true.

Fungi are able to break down insoluble organic matter by releasing exoenzymes, which are enzymes that are secreted outside of the fungal cells. These exoenzymes break down complex organic compounds into simpler, soluble forms. Once the nutrients are solubilized, the fungi can then absorb them and use them for their growth and metabolism. Therefore, the statement that fungi digest insoluble organic matter by secreting exoenzymes and absorbing the solubilized nutrients is true.

Fungi play a crucial role as decomposers in ecosystems. They break down dead organic matter, such as fallen leaves and dead animals, into simpler compounds, releasing nutrients back into the environment. This process is essential for nutrient cycling and the recycling of organic material. Fungi also help in the decomposition of wood, aiding in the breakdown of lignin, a complex compound that is difficult to degrade. Overall, fungi's role as decomposers is vital for maintaining the balance and health of ecosystems.

Protozoa are a group of single-celled organisms that belong to the kingdom Protista. They are considered protists because they share common characteristics with other members of this kingdom, such as being eukaryotic (having a nucleus) and not fitting into any other specific group of organisms. Protozoa exhibit a wide range of diversity in terms of their morphology, behavior, and habitat, but they are all classified as protists. Therefore, the statement "Protozoa are protists" is true.

Kelps are indeed the largest of the brown algae, with some species growing up to 75 meters in length. This statement is supported by scientific evidence and is therefore true.

Mycoses is the correct answer because it refers to diseases in animals caused by fungi. The term "mycoses" is derived from the Greek word "mykes" meaning fungus. Fungal infections in animals can affect various parts of the body and can be localized or systemic. Examples of mycoses in animals include ringworm, aspergillosis, and candidiasis.

A contractile vacuole is a unique organelle found in some protozoa, such as amoebas and paramecia, but not in higher animal cells. It functions to regulate the water balance within the cell by collecting excess water and expelling it from the cell. This organelle is necessary for these single-celled organisms to maintain osmotic balance and prevent them from bursting due to excessive water intake.

The green algal division is most likely the ancestor of higher plants. This is because green algae and higher plants share many similarities in terms of cellular structure, photosynthetic pigments, and reproductive strategies. Additionally, green algae are known to have evolved complex multicellular forms, which is a characteristic shared with higher plants. Therefore, it is highly probable that the green algal division gave rise to the ancestors of higher plants.

Binary fission is the most common method of asexual reproduction in protozoa. In binary fission, the parent cell divides into two equal daughter cells, each with identical genetic material. This process allows the protozoa to reproduce rapidly and efficiently. Budding is a form of asexual reproduction where a smaller outgrowth forms on the parent organism and eventually detaches to become a new individual. Cytokinesis is the process of cell division, which is a part of binary fission. Fragmentation is a form of asexual reproduction where the parent organism breaks into fragments, each of which can develop into a new individual.

Fungi are able to digest macromolecules through extracellular enzyme activity. Unlike phagocytosis, which involves engulfing and digesting particles within the cell, fungi secrete enzymes outside their cells to break down complex molecules into smaller, more easily absorbed components. This process is known as extracellular digestion. Active transport, on the other hand, refers to the movement of molecules across a cell membrane using energy, and is not directly involved in the digestion of macromolecules.

Protozoan cysts serve multiple functions. They act as a protective mechanism against adverse changes in the environment, allowing the protozoan to survive in harsh conditions. Cysts also serve as a site for nuclear reorganization, enabling the protozoan to undergo necessary changes before returning to an active state. Additionally, cysts serve as a means of transfer from one host to the next, allowing the protozoan to spread and infect new hosts. Therefore, the correct answer is "all of these".

Fungi can exist as single cells, known as yeasts, or as multicellular organisms. However, the statement suggests that fungi mainly exist as single cells, which is true.

Alginates are made from brown algae. Brown algae are a type of seaweed that contain a substance called alginate, which is extracted and used as a thickening agent in emulsions. This natural polysaccharide has unique properties that make it an ideal ingredient for thickening and stabilizing various products, including food, pharmaceuticals, and cosmetics. Brown algae are abundant in coastal areas and are harvested for their alginate content, making them a sustainable and renewable source for the production of alginates.

The statement is false because fungi are not separated from plants based on the chemistry of their cell walls. Fungi are actually classified as a separate kingdom in the biological classification system, distinct from plants. While both fungi and plants have cell walls, the composition and structure of their cell walls are different. The classification of fungi is based on various factors such as their mode of nutrition, reproductive structures, and genetic characteristics, rather than just the chemistry of their cell walls.

Chlamydomonas is a motile green algae because it possesses two flagella, which enable it to move through water. This characteristic distinguishes it from the other options listed, as Chlorella is non-motile, Volvox moves as a colony, and Spirogyra lacks flagella and moves by the flow of water.

Algae can be described as plants, protists, and bacteria because they exhibit characteristics of all three groups. Some types of algae, like seaweed, have plant-like features such as chlorophyll and the ability to photosynthesize. Other types of algae, like diatoms, are classified as protists because they have a complex cell structure and do not fit into the plant or animal kingdom. Additionally, certain types of algae, like cyanobacteria, are classified as bacteria due to their prokaryotic cell structure. Therefore, algae can be categorized as all of these groups.

Agar is made from red algae, specifically from the cell walls of certain species. Green algae and brown algae do not produce agar.

Zooxanthellae are algae that have a symbiotic relationship with corals. They live inside the coral tissues and provide essential nutrients through photosynthesis. This relationship is crucial for the survival and growth of coral reefs. Lichens are a different type of organism that consists of a symbiotic relationship between fungi and algae or cyanobacteria. Phytoplankton refers to microscopic algae that float in the water and are not specifically associated with corals. Therefore, the correct answer is zooxanthellae.

According to the classical classification scheme, protozoa are classified into seven phyla.