An organism is multicellular, eukaryotic, heterotroph with cell walls containing chitin. It is most likely a(n): A. plant B. animal C. eubacterium D. archaea E. fungus QUESTION 20 Which of the following are essential parts of a “seed”? A. a plant sporophyte embryo B. stored food C. protective coating D. All of the above E. B and C only QUESTION 21 Which of the following is NOT an ecological role of fungi? A. supporting plant life via mycorrhizal symbioses B. recycling materials as decomposers C. pioneering bare rock and other sparse environments via mutualistic relationships as lichens D. independent (non-symbiotic) production of organic material as photosynthetic autotrophs E. infecting other organisms as parasitic symbionts
The Correct Answer and Explanation is:
QUESTION 19
Correct Answer: E. Fungus
Explanation:
The organism described is multicellular, eukaryotic, heterotrophic, and has cell walls containing chitin. These are defining characteristics of fungi. Fungi differ from plants in that they do not carry out photosynthesis; instead, they obtain nutrients by absorbing them from their environment. They digest food externally by releasing enzymes into the surroundings and then absorbing the resulting nutrients. Unlike plants whose cell walls contain cellulose, fungal cell walls are made of chitin, a strong, flexible polysaccharide. Additionally, fungi are eukaryotic, meaning they have a defined nucleus and membrane-bound organelles. This distinguishes them from prokaryotic organisms such as eubacteria and archaea. Animals, although also multicellular and heterotrophic, do not have cell walls, which eliminates them from this classification.
QUESTION 20
Correct Answer: D. All of the above
Explanation:
A seed is a reproductive structure in seed plants that ensures the development and survival of the plant embryo. It has three essential parts:
- Embryo – the developing plant (a young sporophyte), which will grow into the new plant.
- Stored Food – provides nourishment to the embryo during germination before it can perform photosynthesis.
- Protective Coating – typically called the seed coat, this layer protects the seed from physical damage, desiccation, and pathogens.
These three parts work together to ensure that the plant can survive unfavorable environmental conditions and resume growth when conditions improve. Therefore, the correct answer includes all these components.
QUESTION 21
Correct Answer: D. Independent (non-symbiotic) production of organic material as photosynthetic autotrophs
Explanation:
Fungi are heterotrophic organisms, meaning they cannot produce their own food like autotrophs (such as plants and some bacteria). They do not carry out photosynthesis and thus cannot fix carbon independently. Instead, fungi absorb nutrients from organic material—living or dead—making them excellent decomposers in ecosystems. Fungi also form symbiotic relationships, such as mycorrhizae (with plant roots) and lichens (with algae or cyanobacteria), which help in nutrient cycling and colonization of harsh environments. Some fungi are parasitic, feeding on living organisms and sometimes causing disease. However, they are never photosynthetic or independently autotrophic, which makes choice D incorrect regarding their ecological roles.
