Which of the following statements concerning living phytoplanktonic organisms are true?
d. 2, 3, and 5
Biologists have discovered the kingdom Protista to be paraphyletic. Which of the following statements is true, and consistent with this conclusion?
e. The protists arose from a common ancestor that was a parabasalid.
The strongest evidence for the endosymbiotic origin of eukaryotic organelles is the similarity between extant prokaryotes and which of the following?
b. mitochondria and chloroplasts
According to the endosymbiotic theory of the origin of eukaryotic cells, how did mitochondria originate?
b. from engulfed, originally free-living prokaryotes
Which of the following statements is consistent with the hypothesis that certain eukaryotic organelles originated as prokaryotic endosymbionts? Such organelles
b. can be cultured on agar since they make all their own proteins.
Which process allows nucleomorphs to be first reduced, and then lost altogether, without the loss of any genetic information from the host cell that ultimately surrounds the nucleomorph?
b. horizontal gene transfer
Which organisms represent the common ancestor of all photosynthetic plastids found in eukaryotes?
The chloroplasts of modern plants are thought to have been derived according to which sequence?
a. cyanobacteria green algae green plants
A mixotroph loses its plastids yet continues to survive. Which of the following most likely accounts for its continued survival?
c. It engulfs organic material by phagocytosis.
A biologist discovers a new unicellullar organism that possesses more than two flagella and two small, but equal-sized, nuclei. The organism has reduced mitochondria and no chloroplasts. How would you classify this organism?
Which two genera have members that can evade the human immune system by frequently changing their surface proteins?
b. 1 and 4
Which of the following marine organisms produce potent neurotoxins that cause extensive fish kills, contaminate shellfish, and create severe respiratory irritation to humans along the shore?
Which of the following statements about dinoflagellates is false?
e. Their fossil remains form limestone deposits.
Which group(s) within the Alveolata include(s) members that are important in ocean food webs, cause(s) red tides that kill many fish, and may even be carnivorous?
Which of the following statements concerning protists is false?
b. The organism that causes malaria is transmitted to humans by the bite of the tsetse fly.
You are given an unknown organism to identify. It is unicellular and heterotrophic. It is motile, using many short extensions of the cytoplasm, each featuring the 9+2 pattern. It has well-developed organelles and three nuclei, one large and two small. This organism is most likely to be a member of which group?
Which of the following is not characteristic of ciliates?
c. They can exchange genetic material with other ciliates by the process of mitosis.