Eukaryotes

The endosymbiotic theory for the origin of eukaryotes hypothesizes that the ancestral eukaryote a. engulfed other cells without destroying the engulfed cells. b. had nuclear genes to build mitochondria. c. engulfed a bacterium after that bacterium engulfed a cyanobacterium, like Russian nesting dolls...or a turducken. d. Formed a secondary membrane as a protective nucleus around its DNA. e. There is support for all of these.

a

If an organism is capable of photosynthesis, it is not a protist. True False

False (Protists have a diversity of ways they generate energy and gain resources, which includes photosynthesis.

Describe at least two differences in cellular structure or metabolism between prokaryotes and eukaryotes.

Nucleus (nuclear envelope with nuclear pores), Mitochondria,a cytoskeleton containing the structural and motility components, Flagella and cilia, linear chromosomes, etc. Note that eukaryotic organisms including fungi, plants, and some protists do have cell walls, but the cell walls are composed of different biomolecules than those of prokaryotes.

The appearance of abundant multicellular organisms coincided with increased levels of _________ in the Earth's atmosphere. Oxygen Hydrogen Nitrogen All of the above None of the above

oxygen

In the Endosymbiotic Theory for the origin of eukaryotes, the final step was the engulfing a functional cyanobacterium to produce photosynthetic eukaryotes ("plants"). Why is this stage considered the final step in the sequence of eukaryote evolution?

All photosynthetic eukaryotes have mitochondria

Which major event (or events) likely allowed eukaryotes to evolve? (select all that apply) a. continental drift b. oxygenation of atmosphere c. global warming d. global cooling e. glaciation f. impact from a large meteor g. volcanic activity

B

Which statement correctly describes the relationship between protists and other organisms? a. Protists comprise most of the human microbiome. b. Some pathogenic protists are transported by insects. c. Protists often form mutualistic relationships with plants, fixing atmospheric nitrogen for the plant while receiving sugars form the plant. d. A and B E. A and C

B

Which of the following do protists have that bacteria don't? a. ribosomes b. nucleus c. plasma membrane d. Golgi apparatus e. flagella f. chromosome g. RNA h .mitochondria

B, D, H

Eukaryotes evolved from prokaryote ancestors (the Endosymbiont Theory being a likely pathway). While eukaryotes share some traits with their prokaryote ancestor(s), some features are unique. From the list below, select those features unique to eukaryotes. a. circular double-stranded DNA in the nucleus b. ribosomes are used for protein synthesis c. membrane-bound organelles d. mitosis e. mitochondria f. photosynthesis g. motility h. histones associated with DNA

C, D, and E

Which of the following are roles that protists play? Human pathogens and parasites Human parasites Plant pathogens Plant parasites Photosynthetic organisms Decomposers

all of the above

Which of the following describe ways in which some protists can obtain energy? By ingesting and digesting prey By decomposing dead organic matter By being a parasite within other species By conducting photosynthesis By forming mutualistic symbioses with other species

all of the above

Which of the following best describes the true location of protists on the tree of life? a. Protists are a monophyletic sister taxon of plants. b. Protists are a polyphyletic group that describe various prokaryotes. c. Protists are vastly diverse paraphyletic group of eukaryotes. d. Protists are the outgroup of the Kingdom Animalia. e. Protists are the extinct ancestors of fungi, plants and animals.

c

Which of the following statements concerning endosymbiosis is true? a. The endosymbiosis of a proteobacterium allowed for the development of proteins in higher order Eukaryotes. b. The endosymbiosis of cyanobacterium allowed for the development of the mitochondria. c. The development of mitochondria occurred before the development of the chloroplasts in Eukaryotic lineages. d. Plants enabled photosynthetic bacteria to develop chloroplasts via horizontal gene transfer. e. None of the above are correct

c (Organisms with chloroplasts also have mitochondria, so the phylogeny with the most parsimony has mitochondria evolving first.)

Which is true of mitochondrial and chloroplast origins? a. Mitochondria emerged over 3 BYA; chloroplasts as recently as 1 BYA. b. Chloroplasts were established before mitochondria. c. Chloroplasts and mitochondria arose simultaneously d. Mitochondria arose before chloroplasts. e. We do not know this information.

d

You have found a new eukaryote. What line of evidence would support your hypothesis that the organism is a photosynthetic protist? A. It lacks a cell wall. B. It forms chains of cells. C. it has a cellulose cell wall. D. It is able to produce oxygen in the light. E. it requires only inorganic nutrients and does not require preformed organic matter to grow.

d

Which life cycle relies on a sole multicellular diploid stage that produces haploid gametes? diplontic haplontic alternation of generations mitosis meiosis

diplontic

A species that has a multicellular haploid life stage is a. Diplontic b. Haplontic c. Haplodiplontic d. All of these. e. B and C.

e

Which of the following is not a true statement about Protista (protists)? a. It is an artificial grouping. b. Its members are both motile and sessile c. It contains unicellular, colonial, and multicellular groups. d. Some members cause disease e. Its members have DNA that floats in the cytosol

e