Which describes how heterotrophs obtain their energy and organic nutrients?

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1 MCAT Biology Problem Drill 09: Becteria, Prokarotes and Fungi Question No. 1 of 10 Which describes how heterotrophs obtain their energy and organic nutrients? Question #01 A. Heterotrophs produce some organic nutrients, and must absorb inorganic nutrients from the environment. B. Heterotrophs can produce all their own nutrients. C. Heterotrophs are unable to synthesize organic compounds and must obtain their nutrition from another heterotroph or an autotroph. D. Heterotrophs require no nutrients. Heterotrophs cannot produce organic compounds on their own. Autotrophs are capable of producing their own nutrients. C. Correct! Heterotrophs require other organisms for organic, carbon based nutrients. All living organisms require nutrition from some source. Remember heterotroph comes from the greek heterone (another) and trophe (nutrition); and needs others for survival while autotroph from autos (self) and trophe (nutrition) are selfsustaining.

2 Question No. 2 of 10 Which is/are true of the reproductive capabilities of fungi? Question #02 A. Fungi only undergo asexual reproduction. B. Fungi only undergo sexual reproduction. C. Fungi can undergo both sexual and asexual reproduction. D. Fungi use binary fission to reproduce. Fungi are not restricted to just asexual reproduction like bacteria is. Fungi are also not restricted to sexual reproduction. C. Correct! Fungi are capable of both sexual and asexual reproduction; asexual usually occurs when nutrients and water are abundant and sexual when nutrients and water are scarce. Bacteria use binary fission, fungi are eukaryotes with a more complicated reproductive cycle. Review the reproductive processes of fungi.

3 Question No. 3 of 10 Bacterial pilli play a role in. Question #03 A. chromosomal replication. B. binary fission C. conjugation D. none of the above Pilli do not participate in chromosomal replication. Binary fission does not require pilli. C. Correct! Pilli serve as the bridge through which plasmid DNA moves from one bacterial cell to another. There is one correct answer above. Review the processes of binary fission, conjugation, and transformation.

4 Question No. 4 of 10 The individual filaments that make up a mycelium are called (A), which are long strings of cells that may be divided by (B). Question #04 A. spindle fibers, septa. B. septa, spindle fibers. C. hypha, septa. D. chitin, coenocytic. Mycelium are not made of spindle fibers. Septa are not filaments in mycelium. C. Correct! Septa divide hyphae, which collectively make up the mycelium. Chitin is cell wall component in fungi. Review the organization of fungi.

5 Question No. 5 of 10 Which of the following difference between Archaea and Eubacteria is NOT true? Question #05 A. Eubacteria contain murien peptidoglycan cell walls. B. Archae exist in extreme environmental conditions. C. Only Eubacteria are human pathogens. D. Archae undergo sexual reproduction. This is a true statement. Murein is a large component of Eubacterial cell walls. This is a true statement. Archaea exist is high temperature, extreme ph and organically toxic environments. C. Incorrect! This is a true statement. Archaea do not infect humans. D. Correct! This is the only false statement among the choices. Archaea undergo binary fission like other prokaryotes, a form of asexual reproduction in single-celled organisms. Review the differences between Archeae and Eubacteria. Remember Archaea are prokaryotes and reproduce as such. The special aspects of Archaea are their environments, cell wall components, and inability to infect humans.

6 Question No. 6 of 10 Which of these organelles are found in prokaryotic cells? Question #06 A. mitochondria B. ribosomes C. centrioles D. lysosomes Prokaryotes do not possess mitochondria. B. Correct! Ribosomes are founding prokaryotes. C. Incorrect! Prokaryotes do not have any nuclear organization structures. Prokaryotes do not have lysosomes. Ribosomes are the only membrane bound organelles a prokaryote contains.

7 Question No. 7 of 10 Bacteria replication is best described by. Question #07 A. mitosis B. meiosis C. binary fission D. log phase growth Mitosis does not occur in bacteria. Bacteria do not undergo sexual reproduction. C. Correct! Bacteria undergo binary fission in which two identical cells are produced from a single precursor. While bacterial growth can be found in log phase, it is not a method of replication. Bacteria cannot undergo any segregation of DNA due to the lack of nuclear organelles such as centrioles. Binary fission is the method of replication in bacteria.

8 Question No. 8 of 10 Which of the following statements best describes fungi? Question #08 A. All are eukaryotic, multicellular autotrophs. B. All are eukaryotic heterotrophs that feed by absorption. C. All are prokaryotic, multicellular autotrophs. D. All are eukaryotic heterotrophs that feed by ingestion. Not all fungi are multicellular. B. Correct! Fungi are eukaryotic, and feed by absorption. C. Incorrect! Fungi are not prokaryotic. Fungi cannot ingest food. Notice this question asks which best describes fungi. While some fungi are multicellular, not all are. The best description is eukaryotic heterotrophs.

9 Question No. 9 of 10 Which of the following statements is not true of prokaryotic cells? Question #09 A. Prokaryotic cells are single cellular. B. Prokaryotic cells have a nucleus. C. Prokaryotic cells have circular DNA. D. Prokaryotic cells have flagella. This statement is true. Prokaryotes are single celled organisms that may live in groups. B. Correct! This statement is false. Prokaryotes lack a nucleus. C. Incorrect! This statement is true. DNA in prokaryotes is circular. This statement is true. Prokaryotes may have flagella. Remember this question asks which is not true of prokaryotes.

10 Question No. 10 of 10 One type of DNA found in a prokaryotic cell is. Question #10 A. circular in the nucleus B. plasmid in the cytoplasm C. circular in the endoplasmic reticulum D. none of the above Prokaryotes have no membrane bound nucleus. B. Correct! Smaller plasmid DNA structures can be found in the cytoplasm. C. Incorrect! Prokaryotes do not contain endoplasmic reticular structures. There is one correct answer above. Remember prokaryotes have no nucleus or individual chromosomes. They have one large circular chromosome that resides in the nucleoid, and may have smaller circular plasmids in the cytoplasm.