Homework Questions Prokaryotes, Protists, and Fungi

What is the nature of the relationship between ants and the fungus that they farm?

Ants eat the hyphae of the fungus, and the fungus "eats" the leaves provided by the ants. This answer choice is correct because the ants eat the fungi's hyphae tips, which contain the nutrients they need; the ants also provide the fungus with leaves to decompose, which provides the fungus with the nutrients it needs.

Complete the following sentence: Ciliates all have...

-A contractual vacuole. -Two nuclei. -Specialized food vacuoles. -Lysosomes that carry enzymes for digestion.

Which type of feeding process do protists utilize?

-Phototrophic -Autotrophic -Heterotrophic -Mixotrophic This answer is correct because protists are diverse in many ways, including feeding processes.

A research group was looking to develop a fuel using photosynthetic protists. Which group of protists is most plant-like?

Archaeplastida. This answer choice is correct because many species in this group are photosynthetic and closely related to plants.

Which group of protists is believed to have been the first to engulf cyanobacteria, the predecessors to chloroplasts?

Archaeplastida. This answer is correct because the Archaeplastida includes photosynthetic plants and algae, and scientists believe this main group was the first to engulf cyanobacteria as endosymbionts.

Plastids in red and green algae contain the DNA of which group of organisms?

Cyanobacteria. This answer is correct because the DNA of cyanobacteria is found within red and green algae lineages.

Fungi and animals are both heterotrophic. How do their modes of nutrition differ?

Animals are heterotrophic by ingestion while fungi are heterotrophic by absorption. This answer is correct because animals digest food internally while fungi secrete extracellular enzymes to break down food for absorption.

Which two characteristics and/or components can be found in many species from the Excavata group of protists?

Diverse types of flagella and altered or missing mitochondria. This answer choice is correct because this group does exhibit diverse forms of flagella and altered or missing mitochondria.

Endospores can help bacteria to survive long periods of what kind of conditions?

Heat Cold Desiccation Nutrient Starvation This choice is correct because some bacteria can survive all of the conditions identified in the other choices by forming endospores.

Which of the following statements is TRUE of prokaryotic diversity?

Horizontal gene transfer played an important role in prokaryotic diversification. This answer is correct because horizontal gene transfer increases the number of genes available to prokaryotes; those genes are then subject to evolutionary forces, which results in greater diversity.

How does the ability to exhibit taxis benefit bacteria?

It can help them move towards nutrients and oxygen and away from toxins. This answer is correct because the benefits of taxis include movement toward nutrients and oxygen and away from toxins.

Which is NOT true of most bacterial genomes?

It is found within the nucleus. This choice is correct because bacteria DO NOT HAVE a nucleus.x

Which specialized organelle belongs to members of Excavata and is used to produce energy under anaerobic conditions?

Kinetoplast. This answer is incorrect because kinetoplasts are organelles that contain DNA.

Scientists investigated the hot and toxic environment near deep-sea hydrothermal vents on the ocean floor. They found organisms from both domain Archaea and domain Bacteria. How can they distinguish between these two groups?

Members of Bacteria have different ribosomal DNA sequences than members of Archaea. This answer is correct because genetic testing of ribosomal DNA sequences distinguishes members of Archaea and Bacteria from each other.

Complete the following sentence: The number of protist species is estimated to be in the...

Millions. This answer is correct; estimates suggest there are much more than a million individual protist species.

Why do people living in areas with Plasmodium, the protist that causes malaria, combat the disease by spraying insecticides to kill mosquitoes?

Mosquitoes are carriers of the Plasmodium. This answer choice is correct because mosquitoes host the protist and can transfer it to humans when the mosquitoes bite humans.

Which statement about the importance of protists to the ocean ecosystems is correct?

Protists are extremely important because many are primary producers sitting at the base of the food web. This answer choice is correct because in the ocean, photosynthetic protists known as phytoplankton convert sunlight into energy that other organisms can consume and use.

How are large ocean organisms like whales dependent on the protists that make up the phytoplankton?

Protists are primary producers. This answer choice is correct because protists are primary producers and so form the base of the food web of the ocean.

Why would a zygomycote species spend energy producing a zygosporangium when food supplies run low?

The zygosporangium can become inactive and has thick walls that can withstand harsh conditions.

Which characteristic is true about basidiocarps?

They can grow extremely quickly. This answer choice is correct because basidiocarps can develop in a matter of hours.

Which of the following is true of glomeromycotes?

They can produce hyphae that help plant roots absorb water and nutrients from the soil. This answer choice is correct because glomeromycotes produce hyphae that grow into plant root cells and increase the effective surface area of the roots. Because of this increased surface area, the plant has more contact with the surrounding soil and can absorb more water and nutrients at once.

What kind of spore do ascomycotes produce when they reproduce asexually?

They produce conidia through asexual reproduction. This answer choice is correct because conidia form from asexual reproduction, which requires less energy and resources than sexual reproduction, and therefore the fungus can produce larger quantities of conidia.

Which service are fungi thought to provide the algae or cyanobacteria in a lichen growing on a bare rock surface?

They provide a source of mineral nutrients and water. This answer is correct because fungi in lichens may provide algae or cyanobacteria with a source of nutrients and water.

Complete the following sentence: Dinoflagellates propel themselves through the water using...

Two flagella. This answer is correct because dinoflagellates have two flagella for propulsion.

A person hiking in the woods notices a spread-out mass growing on a fallen tree trunk. The mass has bulb-like growths developing out of it. To which group of protists does this organism most likely belong?

Unikonta. This answer choice is correct because this group does include slime molds that exhibit sporangia.

Which of the following services does a plant provide to a fungus when they form a mutualism?

a source of carbohydrates. This answer is correct because photosynthetic plants provide mutualistic fungi with a steady source of carbohydrates. Free-living fungi must obtain energy from organic molecules by external digestion and absorption.

Considering only the cells involved in sexual reproduction, at what point during the sexual reproductive cycle can asexual reproduction occur?

after spore release. This answer is correct because once a spore is released, it can enter either type of cycle.

Which order of structures and events correctly reflects the asexual life cycle of an ascomycote?

ascocarp → haploid spores → asexual reproduction. This answer choice is correct because ascocarps do form diploid cells that undergo meiosis to produce haploid spores; these spores develop and reproduce asexually to form conidia.

What group of fungi are known for producing many different kinds of conidia?

ascomycotes. This answer is correct because ascomycotes produce conidia, or spores, during asexual reproduction.

What is the scientific term for the common white button mushroom structure people order and eat on pizza?

basidiocarp. This answer choice is correct because this is the name for the club-like fruiting bodies of basidiomycotes.

Fungi from which group would be most likely found decomposing the lignin of a dead tree?

basidiomycotes. This answer choice is correct because shelf mushrooms break down lignin and are of this group.

A new prokaryotic species is discovered living at the bottom of a deep lake that is fed by runoff from an iron (II) sulfide mine. What would be your best guess as to the type of prokaryote this species might be?

chemoautotroph. This answer is correct. There is a high likelihood that the prokaryote is a chemoautotroph because of the availability of sulfur compounds at the dark bottom of the lake.

Which nitrogen-containing compound is found in both fungal cell walls and arthropod exoskeletons?

chitin. This answer is correct because chitin is the nitrogenous compound that is found in the cell walls of fungi and arthropod exoskeletons.

Which of the following may be a contributing factor to a yeast infection?

compromised immune function. This answer choice is correct because when the immune system is compromised, Candida albicans can become pathogenic, grow unchecked, and create a yeast infection.

Complete the following sentence: Bacterial species that can carry out photosynthesis in the same way as green plants are called...

cyanobacteria. CorrectThis answer is correct because cyanobacteria are photoautotrophs that can carry out plant-like photosynthesis.

Which of the following structures did the ancestor of all fungi have despite being lost in many species?

flagella. This answer choice is correct because the common ancestor of all fungi had a flagellum.

Complete the following sentence: Mycorrhizae are mutualisms between...

fungi and plant roots. This answer is correct because mycorrhizae (fungal-root) are mutualisms between fungi and plant roots.

Which of the following does NOT occur during plasmogamy?

fusion of nuclei. This answer is correct because during plasmogamy only the cytoplasm of two cells combine, not the nuclei.

Which group(s) of fungi combine(s) with an alga or cyanobacterium to form lichen mutualisms?

glomeromycotes, basidiomycotes, and ascomycotes. This answer choice is correct because many species in each of these groups form lichens.

Complete the following sentence: Most fungal biomass exists as a long, thin filamentous structure called a...

hypha(e). This answer is correct because multicellular fungi have developed networks of filaments called hyphae.

After which process or stage does a zygote form in a fungus?

karyogamy. This answer is correct because during karyogamy two nuclei fuse, forming a zygote.

Which of the following is an example of a fungus in a mutualistic relationship?

lichen. This answer is correct because lichens are mutualistic relationships between fungi and either cyanobacteria or algae. Fungi provide moisture and mineral nutrients, and the cyanobacteria or algae provide carbohydrates from photosynthesis.

From what sources can fungi obtain nutrition?

living or dead organisms. This answer is correct because fungi feed on nearly any organic carbon source. Some fungi are symbiotic and obtain nutrition from living organisms; many other fungi are saprophytic and decompose dead matter.

Which of the following terms refers to a fungal infection of an animal, such as athlete's foot?

mycosis. This answer is correct because an infection of a human caused by a fungus, or fungal parasite, is called mycosis.

A previously undescribed freshwater organism is discovered. A molecular phylogeny does not support its placement in the animal clade. It is free-living, heterotrophic, lacks a chitinous cell wall, and does not produce spores. To which of the following taxonomic groups does it most likely belong?

nucleariid.

Complete the following sentence: A prokaryote that gets the energy it needs from sunlight and the carbon it needs from carbon dioxide is called a...

photoautotroph. This answer is correct because prokaryotes that get energy from the sunlight and carbon from carbon dioxide are photoautotrophs.

Which group does NOT share the Opisthokonta clade with fungi?

plants. This answer choice is correct because despite resembling each other physically in some cases, plants and fungi do not share the same ancestor of this clade.

Which order of events is correct for the sexual reproduction cycle in most fungi?

plasmogamy → karyogamy → meiosis. This answer is correct because this order reflects the sexual reproductive cycle, which ends with meiosis followed by spore production.

Complete the following sentence: To carry out their metabolic functions, all prokaryotes must have access to...

some form of energy. This answer is correct because all prokaryotic metabolic reactions require access to some form of energy.

Which of the following is a reproductive structure of lichens?

soredia. This answer choice is correct because soredia are reproductive structures of lichens.

Which characteristic cannot be associated with budding?

spore production. This answer is correct because during budding, spores are not produced.

Which of the following was used to place organisms in the protist kingdom in the former models of classification?

the absence of characteristics from other kingdoms This answer is correct because those organisms that were unable to be placed in other kingdoms were classified as protists.

What direct benefit does a plant provide to a fungus when they are in a mutualistic relationship?

the provision of nutrients. This answer is correct because photosynthetic plants provide nutrients to their symbiotic fungi.

What is the main function of mycelia in fungi?

to increase the surface area for absorption of nutrients and moisture CorrectThis answer is correct because mycelia increase the absorptive surface area of fungi, making the process of absorption much more efficient.

Though it occurs in many non-fungi, which structure forms specifically in chytrid fungi?

zoospore. This answer choice is correct because this is the term for the chytrid motile cell.

Which statement correctly describes secondary endosymbiosis?

A symbiont protist is engulfed by another protist. This answer is correct because in secondary endosymbiosis a protist engulfs a protist that already carries an organelle from an earlier endosymbiosis event.

A scientist collected a sample organism to identify. Which characteristic would eliminate the possibility that the sample was a protist?

A. Visible to Naked eye B. Has a nucleus C. None of the answers are correct Answer is C. This answer is correct because protists are such a diverse group of organisms that few characteristics describe them all.

Which statement correctly describes when a fungal spore will germinate after release?

After landing, environmental conditions must be adequate for germination to occur. This answer is correct because spores will not germinate if there is not enough moisture or light or a warm enough temperature.

Which of the following can happen after a spore is released?

All answers are correct. This answer is correct because all of the choices describe something a spore can do.

In which type of environment are protists found?

All answers are correct. This answer is correct because protists have diverse characteristics that allow them to live in a wide variety of habitats.

Which is a characteristic of all protists?

All protists are eukaryotic. This answer is correct because protists are eukaryotic.

Which group of protists contains organisms with alveoli?

Alveolates. This answer choice is correct because the alveolates in this group have alveoli sacs under the plasma membrane.

How do prokaryotes reproduce?

Binary Fussion and Budding. This is correct because some prokaryotes reproduce through binary fission and others by budding.

Which of these protists encase themselves in calcium carbonate-based coverings?

Both foraminifera and coccolithophorids. This answer is correct because both foraminifera and coccolithophorids have calcium carbonate skeletons.

Which of these protists have silica-based skeletons?

Both radiolarians and diatoms. This answer is correct because both diatoms and radiolarians have silica-based skeletons although they belong to different groups.

Given current understanding of protist diversity, what role did endosymbiosis play in the evolutionary history of red and green algae?

Both red and green algae were products of an original primary endosymbiotic process. A protist engulfed cyanobacteria, evolving into red and green algae. This answer is correct because it describes the role of green and red algae in the endosymbiotic process, based on the current understanding of protist diversity.

How do the dinoflagellates known as zooxanthellae contribute to the functioning of coral reefs?

By providing corals with the products of photosynthesis This answer choice is correct because zooxanthellae live symbiotically within the coral, providing the corals carbohydrates and gaining a stable living environment.

What evidence exists for the secondary endosymbiotic theory?

Certain protists contain organelles that are enclosed in four layers of membranes. This indicates secondary endosymbiosis. This answer is correct because it describes the primary evidence for the secondary endosymbiotic theory.

If you took a sample of pond water on a sunny summer day and looked at it under the microscope, which clade of Excavates would you likely observe?

Euglenids. This answer choice is correct because euglenids are free-living photosynthetic organisms that thrive in well-lit pond water.

A sample of protists revealed organisms that all had a groove running along one side of the cell. To which protist group do the sample organisms probably belong?

Excavata. This answer choice is correct because Excavata species have a groove.

Some protists produce toxic proteins that can harm other organisms. How does this issue relate to human dumping of excess nutrients into the ocean environment?

Excess nutrients cause algal blooms, including blooms of protists with toxins capable of harming marine animal and human health. This answer choice is correct because when humans dump nutrients into the ocean, these excess nutrients cause algal blooms. Some algal blooms are dominated by protists that produce toxins that can harm marine animals and human health.

Which structural component of the bacterial cell is used to move a bacterium from place to place?

Flagella. This is correct; bacteria use flagella for movement.

Which of the following statements is true about the role of fungi in the environment?

Fungi are key decomposers responsible for recycling carbon, nitrogen and other elements through the ecosystem. This answer choice is correct because decomposition is the main role of fungi in the environment.

Which of the following characteristics is common to all fungi?

Fungi use extracellular digestion to break down food molecules. This answer is correct because fungi secrete extracellular digestive enzymes to chemically break down their food sources into a form they can absorb.

Which of the following might be used by a chemotroph as a source of energy?

H2S, Fe2+ and NH3 are correct. This is correct because chemotrophs use inorganic chemicals for their energy needs, and the first three choices each identify an inorganic chemical.

You isolate a cell with chalky white overlapping scales. Which of the seven groups do you hypothesize it belongs to?

Hacrobia. This choice is correct; Hacrobia contains haptophytes, many of which are covered in a calcium carbonate shell.

You observe an amoeba with bulging pseudopodia engulfing prey. Which of the seven groups do you hypothesize it belongs to?

Rhizaria. This choice is correct because Rhizaria include many amoebas that use bulging, thread-like pseudopodia to capture prey.

What benefits to humans can fungi provide?

Select one: A. culinary uses B. pesticides C. brewing D. medicinal uses All answers are correct. CorrectThis answer choice is correct because fungi are beneficial to humans in many ways.

What is a difference between the relationship between protists and termites and protists and mosquitoes in the examples in this module?

Termites rely on protists as mutualists, while mosquitoes are parasitized by protists. This answer is correct. Termites cannot digest their main food source without the cohabiting protist, while mosquitoes are parasitized by the protist as a host and move it among other hosts (such as humans).

Gram staining classifies bacteria into two groups based on which characteristic?

The composition of the cell wall. This answer is correct because Gram staining indicates whether the cell wall has a thick outer layer of peptidoglycan or a thinner peptidoglycan layer.

In basidiomycote fungi, which of the following is an important function of the mushroom?

The correct answer is: disperse sexually produced spores.

Which process would a dikaryotic fungi NOT undergo or have undergone?

The correct answer is: karyogamy.

Which one of the following represents a benefit for a plant with mycorrhizae?

The correct answer is: providing increased access to water and soil nutrients for the plant