Question 1

Protists are considered to represent an artificial kingdom rather than an evolutionary lineage because

Accepted Answer

Protists do not form a natural, monophyletic group, as they are a paraphyletic group of organisms that do not share a single common ancestor. Therefore, they are considered to represent an artificial kingdom rather than an evolutionary lineage.

Question 2

Cells perform many complex processes; in what way does the membranous compartmentalization seen in eukaryotes aid in these processes?

Accepted Answer

Membranous compartmentalization in eukaryotes allows for specific compartments to have unique sets of transport proteins that allow the compartment to accumulate and concentrate the necessary chemical reactants. This aids in the complex processes that cells perform.

Question 3

Which protist life strategy is matched with the appropriate nutritional mode?

Accepted Answer

Phytoplankton are photosynthetic and therefore are photoautotrophs. They can produce their own food using the energy from the sun.

Question 4

The tendency toward sexual reproduction in the more complex eukaryotes suggests a greater number of benefits than asexual reproduction; one potential benefit could be

Accepted Answer

Sexual reproduction involves the combination of genetic material from two individuals, which increases genetic variability in offspring. This can allow for greater adaptability to changing environments and can help prevent the spread and accumulation of harmful mutations.

Question 5

Examine the following evolutionary tree.  One prediction based on the arrangement of protists in the illustration is that the DNA of the

Accepted Answer

The evolutionary tree suggests that green algae are more closely related to plants than to diplomonads, indicating that they would share more DNA in common with plants than with diplomonads.

Question 6

In comparison to eukaryotes,prokaryotes are smaller but have a higher surface area to volume ratio; why might this be advantageous?

Accepted Answer

Prokaryotes lack internal storage compartments, so they need to have a higher surface area to volume ratio to quickly eliminate waste and secure resources from their environment. This helps them to remain competitive. The smaller size allows for a greater surface area to volume ratio, which is advantageous in this regard. The other choices do not explain the advantage of a higher surface area to volume ratio for prokaryotes.

Question 7

Although exceptions exist,reproduction in most eukaryotes involves

Accepted Answer

Most eukaryotes reproduce sexually, which involves the fusion of gametes from two individuals to combine their DNA and form a new genetically diverse organism. Some exceptions do exist, such as asexual reproduction through cell division or self-fertilization. However, the majority of eukaryotic reproduction involves the involvement of two individuals in the process.

Question 8

In addition to a process similar to binary fission in prokaryotes (as seen in Amoeba)and fragmentation (as seen in large multicellular algae),some eukaryotes can also reproduce asexually by

Accepted Answer

Some eukaryotes can reproduce asexually by forming zoospores, which are free-swimming, flagellated spores that can develop into new individuals. Examples of eukaryotes that reproduce by zoospores include some types of fungi, algae, and protozoa.

Answer: D 
 Some eukaryotes can create dormant reproductive structures such as seeds that grow only when environmental conditions are favorable. This is a common method of asexual reproduction in plants. The new individual that grows from the seed is genetically identical to the parent plant.

Question 9

The kingdom Protista is quite diverse and the relationship among its various members is unclear.The best method of clarifying those relationships will require that biologists

Accepted Answer

Creating an evolutionary tree based on comparative DNA data is the best method for clarifying relationships among the diverse members of the kingdom Protista. This method can provide information on the genetic relatedness of organisms and help to identify common ancestors and evolutionary relationships. Removing the kingdom from Eukarya and placing it in its own domain or separating eukaryotic protists from prokaryotic protists may not be the most accurate or helpful method for clarifying relationships within the kingdom. Matching protist traits with corresponding animal traits from a common ancestor may also not be reliable as protists can have unique and diverse characteristics that may not relate directly to animal traits.

Question 10

Biologists hypothesize all of the following advantages for cells of the size typically observed in eukaryotes,EXCEPT

Accepted Answer

Eukaryotic cells are typically larger to accommodate complex structures and functions, but a decrease in recovery time between reproductive events is not a hypothesized advantage of their size.

Question 11

What adaptive advantage do the numerous projections shown in the following microphotograph of the foraminiferans,a type of zooplankton confer?

Accepted Answer

The answer of What adaptive advantage do the numerous projections...

Question 12

The most ancient eukaryotic fossils are similar to red algae,a type of ________abundant today.

Accepted Answer

Red algae are classified as protists, which are a diverse group of eukaryotic microorganisms.

Question 13

Note the location of the air bladders in the following illustration of the kelp; how might these structures represent an adaptive advantage?

Accepted Answer

The location of the air bladders in the kelp represents an adaptive advantage because they act as floats that help orient the photosynthetic cells within the blade toward the surface and sunlight. This positioning maximizes the kelp's photosynthetic efficiency and allows it to thrive in deeper waters that receive less sunlight.

Question 14

Resolving the relationship between the various kingdoms has been challenging because species often resemble one another; for example,the kingdom ________ contains some organisms that are animal-like and others that are plantlike.

Accepted Answer

The kingdom Protista contains a wide variety of organisms that are unicellular or multicellular and have traits that resemble both animals and plants.

Question 15

Eukaryotes display the earliest version of sexual reproduction,whereby

Accepted Answer

Eukaryotes reproduce sexually through the fusion of gametes, which are specialized cells that contain half the genetic material (haploid) of the parent organism. This process results in the formation of a zygote with a full set of genetic material (diploid) that then develops into an offspring. Option A describes sexual reproduction in animals, while option B describes hybridization between different species. Option D describes a form of asexual reproduction called binary fission, which is not related to sexual reproduction.

Question 16

Protists may superficially resemble organisms in the other kingdoms; one exception is the kingdom ________,whose members do not resemble protists in any meaningful way.

Accepted Answer

Bacteria are prokaryotic organisms, which are fundamentally different from protists that are eukaryotic. Protists can resemble fungi, plants, or animals, but not bacteria.

Question 17

What criteria best characterize membership in the kingdom Protista?

Accepted Answer

Protista is a diverse group of eukaryotic organisms that do not fit into the other eukaryotic kingdoms (plants, animals, fungi) due to their varied characteristics and lack of a set of unique shared derived traits.

Question 18

Many biologists have suggested revising the kingdom Protista.The primary problem with the Protista,as shown in the following figure,is that

Accepted Answer

The primary problem with the Protista is that the amoeboid protists are no more closely related to the rest of the group than are animals and fungi, indicating that the current classification model is not based on evolutionary relationships. Therefore, many biologists have suggested revising the kingdom Protista. Options A, B, and C do not address the primary issue with the Protista classification.

Question 19

Most of the cells of a multicellular eukaryote are genetically identical yet may eventually become specialized for specific tasks; how can these differences in cell function be explained?

Accepted Answer

Even though most cells have the same genetic material, they specialize in function by expressing different sets of genes that create unique proteins, affecting the function of the cell. This process is called gene expression, and it is responsible for the differences in cell types in multicellular eukaryotes.

Question 20

The single-celled protists are often mobile and use a variety of propulsive mechanisms,for example,the amoeba move by means of

Accepted Answer

Amoeba move by extending and retracting pseudopodia, or "false feet," which can grasp onto surfaces and propel the cell forward. Cilia and flagella are used by other protists, such as Paramecium and Euglena, but not by amoeba. Coccoliths are calcium carbonate plates found in certain algae and do not relate to cell movement.

Quiz 18: Protista, Plantae, and Fungi