Chapter 25 Review

The evolution of multicellularity in animals has primarily occurred by A) changing how existing genes are used. B) deleting many old genes. C) producing many new genes. D) deleting many old chromosomes.

A) changing how existing genes are used.

Which of the following is the most likely sequence of events, from earliest to most recent, in the evolution of sponges (organisms with many cells that have different functions)? 1. single-celled eukaryote 2. single-celled prokaryote 3. multicellular eukaryote 4. colonial eukaryote A) 2, 1, 4, 3 B) 2, 1, 3, 4 C) 1, 2, 3, 4 D) 1, 2, 4, 3

A) 2, 1, 4, 3

Which of the following was derived from an ancestral cyanobacterium? A) chloroplast B) mitochondrion C) hydrogenosome D) mitosome

A) chloroplast

Which of the following statements concerning protists is correct? A) All protists have mitochondria, although in some species they are much reduced and known by different names. B) The primary organism that transmits malaria to humans by its bite is the tsetse fly. C) All apicomplexans are autotrophic. D) All slime molds have an amoeboid stage that may be followed by a stage during which spores are produced. E) Euglenozoans that are mixotrophic lack functional chloroplasts.

A) All protists have mitochondria, although in some species they are much reduced and known by different names.

The best evidence for not classifying the slime molds as fungi comes from slime molds' A) DNA sequences. B) nutritional modes. C) choice of habitats. D) physical appearance. E) reproductive methods.

A) DNA sequences.

Rhizarians that feed using threadlike pseudopodia include which of the following group(s)? I. forams II. red algae III. cercozoans IV. green algae A) I and III B) II and III C) I and IV D) II and IV

A) I and III

Why can eukaryotes be considered "combination" organisms? A) Some of their genes and cellular characteristics were derived from archaea, and others from bacteria. B) They eventually developed flagella. C) Their diversity outnumbers prokaryotes by over 1 million species. D) They eventually developed cellulose plates.

A) Some of their genes and cellular characteristics were derived from

In a sample of pond water, a new organism is identified with the following characteristics: It consists of 70 cells surrounded by rigid cell walls that join the cells together. Inside each of these identical cells are mitochondria and chloroplasts. Such an organism would most likely be classified as a A) colonial photosynthetic eukaryote. B) fungal photosynthetic eukaryote. C) colonial photosynthetic prokaryote. D) multicellular photosynthetic prokaryote. E) colonial eukaryotic fungus.

A) colonial photosynthetic eukaryote.

The chloroplasts of land plants are thought to have been derived according to which evolutionary sequence? A) cyanobacteria → green algae → land plants B) cyanobacteria → green algae → fungi → land plants C) red algae → brown algae → green algae → land plants D) cyanobacteria → red algae → green algae → land plants

A) cyanobacteria → green algae → land plants

In a synthetic biology experiment, you are given a task to design a new species of aquatic protist. Your design should account for the following characteristics: 1. The protist functions as a primary producer. 2. It cannot swim on its own. 3. It must stay in well-lit surface waters. 4. It must be resistant to physical damage from wave action. Based on these criteria, you decide to model your creation after a(n) A) diatom. B) dinoflagellate. C) apicomplexan. D) red alga. E) radiolarian.

A) diatom.

Imagine you are investigating life in the shallow soils of a forest. In your collected samples, you observe evidence of various single-celled organisms using multiple genetic techniques as well as microscopy. If the organisms you initially assess possess mostly asymmetric or irregular forms, then this particular sample probably has many A) eukaryotes. B) archaea. C) bacteria. D) prokaryotes.

A) eukaryotes.

The life cycle of the malarial parasite, Plasmodium, includes A) haploid and diploid stages both inside the human host and the mosquito. B) a haploid stage diploid inside the human host and both haploid and diploid stages in the mosquito. C) only haploid stages inside the mosquito and diploid states inside liver cells and blood cells of humans.

A) haploid and diploid stages both inside the human host and the mosquito.

A biologist discovers an alga that is marine, multicellular, and can absorb both green and blue light. This alga probably belongs to which group? A) red algae B) brown algae C) green algae D) dinoflagellates

A) red algae

Which two genera have members that can evade the human immune system by frequently changing their cellular membrane surface proteins? 1. Plasmodium 2. Trichomonas 3. Paramecium 4. Trypanosoma A) 1 and 2 B) 1 and 4 C) 2 and 3 D) 2 and 4

B) 1 and 4

Of the four supergroups of eukaryotes, which one contains red algae, green algae, and all land plants? A) SAR B) Archeplastida C) Excavata D) Unikonta

B) Archeplastida

Which statement is correct with regard to the origins of multicellular organisms? A) Multicellular organisms with differentiated cells likely originated from a single common ancestor. B) Multicellular organisms with differentiated cells likely originated from multiple different ancestors. C) Early colonial multicellular organisms had cells that were highly differentiated. D) None of the early multicellular organisms that arose on Earth are still alive today.

B) Multicellular organisms with differentiated cells likely originated from multiple different ancestors.

Green algae differ from land plants in that some green algae A) are heterotrophs. B) are unicellular. C) have plastids. D) have alternation of generations. E) have cell walls containing cellulose.

B) are unicellular.

All protists are A) unicellular. B) eukaryotic. C) symbionts. D) monophyletic. E) mixotrophic.

B) eukaryotic.

A snail-like, coiled, porous test (shell) of calcium carbonate is characteristic of which group? A) diatoms B) foraminiferans C) red algae D) cercozoans

B) foraminiferans

According to the endosymbiotic theory of the origin of eukaryotic cells, how did mitochondria originate? A) from infoldings of the plasma membrane, coupled with mutations of genes for proteins in energy-transfer reactions B) from engulfed, originally free-living proteobacteria C) by secondary endosymbiosis D) from the nuclear envelope folding outward and forming mitochondrial membranes E) when a protoeukaryote engaged in a symbiotic relationship with a protocell

B) from engulfed, originally free-living proteobacteria

Which of these observations gives the most support to the endosymbiotic theory for the origin of eukaryotic cells? A) the existence of structural and molecular differences between the plasma membranes of prokaryotes and the internal membranes of mitochondria and chloroplasts B) the similarity in size between the cytosolic ribosomes of prokaryotes and the ribosomes within mitochondria and chloroplasts C) the size disparity between most prokaryotic cells and most eukaryotic cells D) the observation that some eukaryotic cells lack mitochondria

B) the similarity in size between the cytosolic ribosomes of prokaryotes and the ribosomes within mitochondria and chloroplasts

Which pair of alternatives is highlighted by the life cycle of the cellular slime molds, such as Dictyostelium? A) prokaryotic or eukaryotic B) unicellular or multicellular C) diploid or haploid D) autotroph or heterotroph

B) unicellular or multicellular

Comparisons of choanoflagellate and animal genome sequences tell us that key steps in the transition to multicellularity in animals involved new ways of using proteins or parts of proteins that were encoded by genes found in A) multicellular eukaryotes. B) unicellular protists. C) unicellular bacteria. D) unicellular archeae.

B) unicellular protists.

The last common ancestor of fungi and animals was most likely a A) multicellular photosynthetic eukaryote. B) colonial photosynthetic prokaryote. C) multicellular photosynthetic prokaryote. D) single-celled eukaryote.

D) single-celled eukaryote.

What does scientific evidence indicate to be the correct sequence of these events, from earliest to most recent, in the evolution of life on Earth? 1. origin of mitochondria 2. origin of multicellular eukaryotes 3. origin of chloroplasts 4. origin of cyanobacteria 5. origin of fungal-plant symbioses A) 4, 3, 2, 1, 5 B) 4, 1, 2, 3, 5 C) 4, 1, 3, 2, 5 D) 4, 3, 1, 5, 2 E) 4, 3, 1, 2, 5

C) 4, 1, 3, 2, 5

Why is the filamentous morphology of the slime molds considered a case of convergent evolution with fungi? A) Water molds evolved from filamentous fungi. B) Body shape reflects ancestor-descendant relationships among organisms. C) DNA sequence analyses indicate that slime molds descended from different unicellular ancestors than did fungi. D) Filamentous body shape is evolutionarily ancestral for all eukaryotes.

C) DNA sequence analyses indicate that slime molds descended from different unicellular ancestors than did fungi.

Diatoms are mostly asexual members of the phytoplankton. They obtain their nutrition from functional chloroplasts, and each diatom is encased within two porous, glasslike valves. Which question would be most important for one interested in the day-to-day survival of individual diatoms? A) How does carbon dioxide get into these protists with their glasslike valves? B) How do diatoms get transported from one location on the water's surface layers to another location on the surface? C) How do diatoms with their glasslike valves keep from sinking into poorly lit waters? D) How do diatoms with their glasslike valves avoid being shattered by the action of waves? E) How do diatom sperm cells locate diatom egg cells?

C) How do diatoms with their glasslike valves keep from sinking into poorly lit waters?

Which of the following organism pairs is/are an example of secondary endosymbiosis? I. red algae-heterotrophic eukaryote II. green algae-heterotrophic eukaryote III. E. coli bacteria-photosynthetic cyanobacterium IV. Chlamydomonas and Gonium A) I only B) III and IV C) I and II D) II and III

C) I and II

Protists are I) complex at the cellular level, even though they're simple compared with other eukaryotes. II) typically water-living. III) mostly unicellular. IV) exclusively heterotrophic. A) I only B) I and II only C) I, II, and III D) I, II, III, and IV

C) I, II, and III

An individual mixotroph loses its plastids yet continues to survive. Which of the following most likely accounts for its continued survival? A) It relies on photosystems that float freely in its cytosol. B) It must have gained extra mitochondria when it lost its plastids. C) It engulfs organic material by phagocytosis or by absorption. D) It has an endospore. E) It has multiple alveoli.

C) It engulfs organic material by phagocytosis or by absorption.

Some scientists who study organismal classification believe that green algae should be in an expanded "plant" kingdom called Viridiplantae. If land plants are excluded from this kingdom, then what will be true of it? A) It will be monophyletic. B) It will more accurately depict evolutionary relationships than does the current taxonomy. C) It will be paraphyletic. D) It will be a true clade.

C) It will be paraphyletic.

Which statement is correct with regard to the comparison of secondary endosymbiosis to primary endosymbiosis? A) In secondary endosymbiosis, an entire free-living alga is ingested into the food vacuole of a heterotrophic eukaryote. B) In secondary endosymbiosis, an entire free-living alga is incorporated into the mitochondrion a heterotrophic eukaryote. C) Primary endosymbiosis is the result of alga being engulfed by a cyanobacterium. D) Primary and secondary endosymbiosis are essential equivalent but occurred at different points in time in the evolution of life.

C) Primary endosymbiosis is the result of alga being engulfed by a cyanobacterium.

Multicellular colonies of plant cells adhere to each other primarily by ________, whereas multicellular colonies of animal cells are typically held together by ________. A) fusion of cellular membranes; cell walls B) cell walls; fused cellular membranes C) cell walls; proteins D) interlocking chloroplasts; interlocking mitochondria E) interlocking cellular shapes; large, calcified capsules

C) cell walls; proteins

The evolution of multicellularity in animals required adaptations that promoted A) cellular migration and intercellular communication. B) cellular migration and cellular adhesion. C) cellular adhesion and intercellular communication. D) photosynthesis and cellular migration. E) cellular fusion and regeneration.

C) cellular adhesion and intercellular communication.

The chloroplasts of all of the following are thought to be derived from ancestral red algae, except those of A) diatoms. B) dinoflagellates. C) green algae. D) brown algae.

C) green algae.

A large seaweed that floats freely on the surface of deep bodies of water would be expected to lack which of the following? A) alveoli B) bladders C) holdfasts D) flagella

C) holdfasts

Which of the following is (are) mutualistic partnerships between a protist and a host organism? I. cellulose-digesting gut protists-wood-eating termites II. dinoflagellates-reef-building coral animals III. Trichomonas-humans IV. algae-certain foraminiferans A) I only B) II and IV C) I, II, and III D) I, II, and IV

D) I, II, and IV

Which of the following statements support(s) the theory of the endosymbiotic origin of mitochondria and plastids? I) Mitochondria and plastids have circular DNA and replicate by splitting. II) Mitochondria and plastids have ribosomes. III) Mitochondrial and plastid ribosomal RNA sequences are more similar to cytoplasmic ribosomes than to bacterial ones. IV) The inner membranes of plastids and mitochondria have transport proteins homologous to those in bacterial plasma membranes. A) I only B) I and II only C) III only D) I, II, and IV

D) I, II, and IV

Why is there controversy surrounding the eukaryotic tree? A) It suggests that the unikonts are evolutionarily derived from the archeplastids. B) It suggests that amoebozoans are more closely related (evolutionarily) to red algae than green algae. C) The tree lacks branches for species that have yet to be classified. D) The root of the tree is uncertain such that it is unknown which supergroup was the first to diverge from all other eukaryotes.

D) The root of the tree is uncertain such that it is unknown which supergroup was the first to diverge from all other eukaryotes.

Which of the following pairs of protists and their characteristics are mismatched? A) apicomplexans-internal parasites B) mixotrophs-combine photosynthesis and heterotrophic nutrition C) euglenozoans-unicellular flagellates D) ciliates-red tide organisms

D) ciliates-red tide organisms