Name______Bio 103 Midterm 2007
1. ) Which of the following is the most common compound in the cell walls of gram-positive bacteria?
A) cellulose
B) lipopolysaccharide
C) lignin
D) peptidoglycan
E) protein
2. What are the cells in a sponge that are primarily responsible for trapping food particles from circulating water?
A) amoebocytes
B) choanocytes
C) mesohyl cells
D) pore cells (porocytes)
E) epidermal cells
3. Why must multicellular organisms keep their cells awash in an "internal pond"?
A) Negative feedback will only operate in interstitial fluids.
B) Cells need an aqueous medium for the exchange of nutrients, gases, and wastes.
C) Cells of multicellular organisms tend to lose water because of osmosis.
D) Cells of multicellular organisms tend to accumulate wastes, a consequence of diffusion.
E) This phenomenon occurs only in aquatic organisms because terrestrial organisms have adapted to life in dry environments.
4. ) Which two structures play direct roles in permitting bacteria to adhere to each other, or to other surfaces?
1.capsules
2.endospores
3.fimbriae
4.plasmids
5.flagella
A) 1 and 2
B) 1 and 3
C) 2 and 3
D) 3 and 4
E) 3 and 5
5. Which of the following is the correct order, from most external to most internal?
1.cell wall
2.plasma membrane
3.capsule
A) 1, 2, 3
B) 1, 3, 2
C) 2, 1, 3
D) 3, 2, 1
E) 3, 1, 2
6. A large seaweed that floats freely on the surface of deep bodies of water would be expected to lack which of the following?
A) thalli
B) bladders
C) blades
D) holdfasts
E) gel-forming polysaccharides
7. Which taxonomic group containing eukaryotic organisms is thought to be directly ancestral to the plant kingdom?
A) golden algae
B) radiolarians
C) foraminiferans
D) apicomplexans
E) green algae
8. 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 oxygen-using metabolism
B) from engulfed, originally free-living prokaryotes
C) by tertiary endosymbiosis
D) from the nuclear envelope folding outward and forming mitochondrial membranes
E) when a protoeukaryote engaged in a symbiotic relationship with a protobiont
9. Both animals and fungi are heterotrophic. What distinguishes animal heterotrophy from fungal heterotrophy is that only animals derive their nutrition
A) from organic matter.
B) by preying on animals.
C) by ingesting it.
D) by consuming living, rather than dead, prey.
E) by using enzymes to digest their food.
10. At which stage would one be able to first distinguish a diploblastic embryo from a triploblastic embryo?
A) fertilization
B) cleavage
C) gastrulation
D) organogenesis
E) metamorphosis
11. Which of the following are not associated with sponges?
A) oscula
B) spongocoels
C) cnidocytes
D) spicules
E) amoebocytes
12. A radially symmetrical animal that has two embryonic tissue layers belongs to which phylum?
A) Porifera
B) Cnidaria
C) Platyhelminthes
D) Nematoda
E) Echinodermata
13. The number of legs an insect has, or the number of vertebrae in a vertebral column, or the number of joints in a digit (such as a finger) are all strongly influenced by ______genes.
A) haploid
B) introns within
C) heterotic
D) heterogeneous
E) Hox
14. While snorkeling, a student observes an active marine animal that has a series of muscular tentacles bearing suckers associated with its head. Segmentation is not observed, but a pair of large, well-developed eyes is evident. The student is observing an animal belonging to which class?
A) Gastropoda
B) Cephalopoda
C) Polyplacophora
D) Polychaeta
E) Bivalvia
15. The major branches of Eumetazoa are the Radiata and the Bilateria. These names refer to what characteristic of these animals?
A) size
B) body symmetry
C) embryonic cleavage
D) types of appendages
E) presence or absence of a nucleus in their cells
16. A land snail, a clam, and an octopus all share
A) a mantle.
B) a radula.
C) gills.
D) embryonic torsion.
E) distinct cephalization
17. Which of the following is not a shared characteristic of all chordates?
A) pharyngeal clefts
B) post-anal tail
C) notochord
D) dorsal, hollow nerve cord
E) four-chambered heart
18. What is a distinctive feature of the chondrichthyans?
A) an amniotic egg
B) unpaired fins
C) an acute sense of vision that includes the ability to distinguish colors
D) a cartilaginous endoskeleton
E) lack of jaws
19. Which of these is not considered an amniote?
A) amphibians
B) non-avian reptiles
C) avian reptiles
D) egg-laying mammals
E) placental mammals
20. Cephalization is primarily associated with
A) adaptation to dark environments.
B) method of reproduction.
C) fate of the blastopore.
D) type of digestive system.
E) bilateral symmetry.
21. What is the single unique characteristic that distinguishes extant birds from other extant animals?
A) a hinged jaw
B) feathers
C) an amniotic egg
D) flight
E) a gizzard
22. Differentiation of teeth is greatest in
A) sharks.
B) bony fishes.
C) amphibians.
D) reptiles.
E) mammals.
23. How do animal structures well suited to specific functions come about?
A) Natural selection favors the most functional structures for a particular environment.
B) Mutations arise to provide required structures for survival in a particular environment.
C) An animal that needs a new function will develop a new structure to provide it.
D) Animals invent structural designs that enhance their functions.
E) Animals continually improve their structures in order to improve their functions.
24. Consider the energy budgets for a human, an elephant, a penguin, a mouse, and a python. The ______would have the highest total annual energy expenditure, and the ______would have the highest energy expenditure per unit mass.
A) elephant; mouse
B) elephant; human
C) human; penguin
D) mouse; python
E) penguin; mouse
25. During the process of digestion, fats are broken down when fatty acids are detached from glycerol. In addition, proteins are digested to yield amino acids. What do these two processes have in common? Both
A) are catalyzed by the same enzyme.
B) occur intracellularly in most organisms.
C) involve the addition of a water molecule to break bonds (hydrolysis)
D) require the presence of hydrochloric acid to lower the pH.
E) require ATP as an energy source.
Short answer – 3 pts. each.
1. Explain how the organization of prokaryotic genomes differs from that of eukaryotic genomes.
2. Describe the organisms that fix nitrogen on earth, and briefly describe the importance of this process.
3. Explain how trypanosomes avoid detection by the human immune system.
4. Describe the evidence that supports the theory that mitochondria and plastids evolved by serial endosymbiosis.
5. Distinguish between radial and bilateral symmetry, and explain how animal symmetry may match the animal’s way of life.
6. List four traits of Cnidarians that distinguish them from other phyla.
7. Distinguish between a gastrovascular cavity and an alimentary canal .
8. Describe the 4 derived traits that define Phylum Chordata
9. Define ecdysis.
10. Distinguish among monotreme, marsupial, and eutherian mammals.
11. .Explain the fate of the neural crest cells in craniate development
12. Describe the relationship between metabolic rate and body size.
13. Describe 4 processes by which animals exchange heat with their environment.
14. Briefly describe three functions of saliva.
15. Explain why pepsin does not digest the stomach lining .
Essays - Worth 15 pts each.
1. Make a table that reflects a current hypothesis for relationships of eukaryotic life on earth, and which includes the 5 protistan supergroups proposed for Eukarya. Include several important members of each group along with one or two key ID characteristics for these members.
2. Draw a phylogenetic tree including 9 different animal phyla. Label important changes in phylum body characteristics and organizational plans on branching structures, showing an evolutionary perspective. Next to the name of each phylum, write a common name for an animal in that phylum.