Question

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answer the question 1) Altprotists are eukaryotic B) mixotrophie Cunicellular D) symbionts 2) An individual mixotroph loses its plastids, yet continues to survive. Which of the following most likely accounts for its continued survival? C lt engulfs organic material by phagocytosis or by absorption 3) It relies on photosystems that float freely in its cytosol. C) It has an endospore. D) It must have gained extra mitochondria when it lost its plastids. Use the following information to answer the question(s) below. Giardia intestinalis is an intestinal parasite of humans and other mammals that causes intestinal ailments in most people who ingest the cysts. Upon Ingestion, each syst releases two motile cells, called trophoroites. These attach to the small intestine's lining via a ventral adhesive disk. The trophozoites anaerobically metabolize glucose from the host's intestinal contents to produce ATP. Reproduction is completely asexual occurring by longitudinal binary fission of trophozoites, with each daughter cell receiving two haploid nuclei (N ). A trophoroite will often encyst as it passes into the large intestine by secreting around itself a case that is resistant to cold, heat, and dehydration. Infection usually occurs by drinking untreated water that contains cysts. 3) The cysts of Giardis function most like the Allendospores of bacteria C) capsids of viruses B) mitochondria of ancestral diplomonads D) nuclei of archaeans 4) The mitosome (reduced mitochondion) of Giardin has no DNA within it. If it did contain DNA, then what predictions should we be able to make about its DNA? 1. It is linear. 2. It is circular. 3. It has many introns. 4. It has few introns. 5. It is not associated with histone proteins. 6. It is complexed with histone proteins. A) 1, 4, and 5 B) 1,3, and 5 C) 2, 3, and 6 2. 4, and 5) If the mitosomes of Glide contain no DNA, yet are descendants of what were once free-living organisms, then where are we likely to find the genes that encode their structures, and what accounts for their current location there? A) plasmids; conjugation ((B) hucleus; horizontal gene transfer C) plasmids, transformation D) nucleus; S phase 1 6) Reinforced, threadlike pseudopods that can perform phagocytosis are generally characteristic of A) Apicomplexians B) dinoflagellates C) water molds D) Rhizaria

Answer 1

1. A    {all protists are categorized as eukaryotes along with plants, animals, and fungi.}

2. A    {it engulfs organic material and by phagocytosis or absorption and acts like heterotroph rather then autotroph}

3. A    {the function of Giardia here is very similar to the function of endospores in the bacteria.}

4. D {it will be a circular DNA, having few non coding sequences (introns) and without any association with histones. So option D suits most)

5. B    (genes should be found in nucleus and horizontal gene transfer mechanism accounts for it}

6. D    (Rhizaria being a forams is most appropriate choice.}

rating !!!!!!