EXAM 2 REVIEW - ANSWERS

  1. Animals and fungi are heterotrophic and have eukaryotic cells.
  2. Fungi acquire nutrition through absorption, while animals acquire nutrition through ingestion.
  3. Fungi are heterotrophs that have diverse lifestyles. The three lifestyles are symbiotic relationships, decomposition, and parasitism. Which type of lifestyle do mychorrizae represent? Symbiotic relationship
  4. Both fungi and arthropods have cell walls made of chitin.
  5. Fungi are composed of long, thin filaments known as hyphae that make up the mycelium of each plant. This should have a large surface area in order to increase absorption rate.
  6. Some fungi have cell walls in their hyphae that are called septa. Not having these means they are aseptate, consist of one cell(s) and have many nuclei.
  7. A specialized form of hyphae that can be parasitic or mutualistic is called haustoria.
  8. When two mycelia (positive and negative) join together to reproduce sexually, their cytoplasm mixes together, a process called plasmogamy. The process that happens afterward when their nuclei fuse is called karyogamy.
  9. What does it mean to be dikaryotic? Which types of organisms can be dikaryotic?Dikaryotic (di=two, kary=nucleus) means a cell has two nuclei that haven’t fused yet. Fungi have this.
  10. Name the three differences between oomycetes (a protist) and fungi.Oomycetes have a diploid dominant ploidy, cell walls made of cellulose and flagellated cells. Fungi have a haploid dominant ploidy, cell walls made of chitin and no flagellated cells.
  11. The dominant stage of fungi is haploid ploidy; for animals, diploid.
  12. What is the product of sexual reproduction? How does asexual differ? When does meiosis occur?The product of sexual reproduction is a zygote. Asexual reproduction differs in that all offspring are identical to the parent and there is no zygote involved. Meiosis occurs in the making of spores.
  13. True or False: Fungi have gametes like animals do.False
  14. True or False: “Imperfect fungi” have no known sexual reproductive stages.True
  15. Why are spores useful to fungi?They are good methods of dispersal.
  16. Zygomycota, a phyla of fungi, produces a zygosporangium. What is its main purpose?To protect the zygote until conditions are favorable.
  17. Ascomycota, a phyla of fungi, produces a sac called a(n) ascus in which it produces ascospores.
  18. What are the four important impacts that fungi have on ecosystems and humans?Decomposers, symbiotic relationships with plants AND animals, human uses and pathogens (on plants AND animals).
  19. Draw a diagram of the early embryonic development. Include the following: blastula, cleavage, gastrula, gastrulation, blastopore. What happens in each step?Zygote –Cleavage Blastula –Gastrulation Gastrula with blastopore. During cleavage mitosis (replication of cells) occurs. During gastrulation the embryo forms germ layers and the blastopore.
  20. What are the three germ layers? Which one is the outside? Inside? Middle?Endoderm (inside), mesoderm (middle) and ectoderm (outside).
  21. Cyclopia in goats is an example of what study of biology?Developmental biology
  22. What are the four parts of animal’s body plan?Symmetry, embryonic development, organization of tissues and type of body cavity.
  23. What phylum is radially symmetric and diploblastic?Cnidaria
  24. What is the difference between radial symmetry and bilateral symmetry? Diploblastic and triploblastic? Deuterostome and protostome?Radially symmetric organisms can be sliced any way and have symmetric pieces. Bilaterally symmetric organisms can only be sliced one way to have 2 symmetric pieces. Diploblastic means 2 germ layers, triploblastic means 3. Deuterostomes develop the anus from the blastopore, and protostomes develop the mouth.
  25. What are the three possible coeloms? Describe them. What characteristic does an animal have to have a body cavity? What is the importance of a body cavity?Acoelomates, which have no coelom (filled with mesoderm); pseudocoelomates, which have a body cavity partially lined with mesoderm; and coelomates, which have a body cavity completely lined with mesoderm. An animal must be triploblastic to have a body cavity. A body cavity is important for the protection of organs, provides space for the growth of organs and acts like a skeleton for some animals.
  26. True or False: There has been one giant cycle of diversification and extinction throughout time.False
  27. Porifera: Name its symmetry, whether or not is has true tissues, what the purpose of choanocytes are. True or False: Porifera organisms have perforated bodies.Asymmetrical; no true tissues; choanocytes are for feeding purposes; true.
  28. Cnidaria: Name its symmetry, whether or not is has true tissues, what the purpose of cnidocytes are, tissue organization. True or False: Cnidarians have a gastrovascular cavity.Radial symmetry; has true tissues; cnidocytes are for feeding; diploblastic; true.
  29. Polyp is the sessile form of Cnidarians, while medusa is the mobile form.
  30. Corals do what two important functions? What phylum do corals belong to?Corals, a part of the Cnidarians, provide environments for other organisms and break tidal waves for islands.
  31. Lophotrochozoans: Name its symmetry, tissue organization, embryonic development, 3 phyla within this group. True or False: Lophotrochozoans begin to show cephalization.Bilateral symmetry; triploblastic; protostome; Platyhelminthes, Mollusca and Annelida.
  32. Platyhelminthes have what type of coelom? Many species that we studied are parasitic/free-living.Acoelomates; parasitic.
  33. Plathelminthes have a pharynx. What is it for?It’s an inverted mouth for eating.
  34. The final host is important to a parasite because that is where sexual reproduction occurs; it is necessary to complete the life cycle.
  35. Parasites have important characterisitics: They do not tend to kill their host, they have an increased reproductive effort and they do change the behavior of their host.
  36. Describe reproductive effort. How is it important to parasites?Parasites have a larger amount of reproductive organs and release more eggs. For parasites, it is necessary because there are less chances of their eggs completing the life cycle (by finding the right host).
  37. The classes Tubellaria, Trematoda and Cestoda all belong to what phylum? Are they parasitic, or free-living?They belong to Platyhelminthes. Tubellaria is free-living, and Trematoda and Cestoda are parasitic.
  38. Mollusca differ from platyhelminthes, in that they are coelomates and have a complete digestive system.
  39. Describe an open vs. closed circulatory system.An open system has a heart that pushes blood into the body (that is then circulated by the organism’s muscles). A closed system has blood that is always contained within vessels and the heart.
  40. Mollusca have five parts to their body plan. What are they and what are they for?Foot for locomotion, mantle for secreting the shell, visceral mass is the bag of organs, shell for protection/rigidity and gills for repiration.
  41. What are the three classes in Mollusca (that we studied)? Give an organism as an example of each.Gastropoda, such as snails or slugs; Bivalvia such as clams, mussels or oysters; and Cephalopoda, such as octopuses or squids.
  42. Annelids: which type of circulatory system, what type of skeleton, what type of coelom. All annelids have distinct body segmentation. Why is it important?Closed circulatory system, hydrostatic skeleton, coelomates. Segmentation is important for the specialization of different regions of the body.
  43. What is the ecological importance of annelids?They digest organic matter/dirt and pass casts, which are excellent fertilizer rich with minerals. They help aerate soil too.
  44. Ecdysozoans: Name its symmetry, tissue organization, embryonic development, 2 phyla within this group. What process is this group named for?Bilateral symmetry, triploblastic, protostome, Nematoda and Arthropoda. It’s named for the molting of the exoskeleton during growth.
  45. Nematodes have an exoskeleton, called a cuticle, which is made of collagen.
  46. What type of coelom do nematodes have? How do they move?They are pseudocoelomates. They move by “thrashing”—contracting muscles against the cuticle.
  47. There are two ecological roles of nematodes: decomposers and parasites, which can affect both humans AND plants!
  48. How do we break the cycle of parasites? (Hint: think of the example having to do with contaminated water…)Get rid of the intermediate host!
  49. Arthropods are EXTREMELY successful. What are the four characteristics related to their success?Segmented bodies, hard exoskeleton, jointed appendages and well-developed head and sensory organs.
  50. Over time, segments in the bodies of arthropods have reduced, leading to a more efficient body plan.
  51. The exoskeleton of arthropods is made of chitin, just like fungi. How is the exoskeleton important?It protects the organism, prevents water loss and is an attachment site for muscles.
  52. How are jointed appendages considered advantageous for arthropods?Appendages have become more specialized for specific functions.
  53. Arthropods have anopen circulatory system and a variety of organs for respiration.
  54. For the four clades of arthropods, name: the number of body regions, number of pairs of legs, presence of antennae, an example of an organism.Chelicerata: 2 body regions, 4 pairs of legs, no antennae, spiders. Crustacea: 2 body regions, 5+ pairs of legs, 2 pairs of antennae, shrimp or crabs. Myriapod: 2 body regions, many legs, one pair of antennae, millipedes or centipedes. Insecta: 3 body regions, 3 pairs of legs, one pair of antennae, insects (grasshoppers, butterflies, gnats, etc.)
  55. True or False: Crustaceans are the most successful group of arthropods.False (Insecta is!)
  56. What are the three major adaptations of insects that led to their success?Flight, specialized mouth parts and metamorphosis.
  57. What are the three ecological effects of insects?Species pollinate plants, are vectors for disease and compete with humans for food.
  58. Deuterostomia: Name its symmetry, tissue organization, embryonic development, 2 phyla within this group.Bilateral symmetry, triploblastic, deuterostomes, Echinodermata and Chordata.
  59. True or False: Starfish are bilaterally symmetric.True
  60. What are the three subphyla of the chordates? Which one is without a head region?Urochordata (no head region), cephalochordate and vertebrata.
  61. All chordates have what four characteristics? Describe each.Notochord, a flexible rod located between the nerve cord and gut, providing skeletal support for muscle attachment; dorsal hollow nerve cord, develops into the central nervous system; pharyngeal slits, openings to the outside of the body at the pharynx for gas and water exchange; and a muscular post-anal tail, a tail found after the anus.
  62. True or False: Larval tunicates don’t look like chordates, but the adults do.False (this should be vice-versa!)
  63. True or False: Vertebrates are the second largest group or organisms, behind arthropods.False (they are only 5% of all organisms!)
  64. What distinguishes vertebrates from the rest of the chordates?Distinct cephalization, vertebral column that encloses the nerve chord (has the function of the notochord), endoskeletons that grow with the animal and a closed circulatory system (more efficient movement of things around the body).
  65. There were many evolutionary events in the vertebrates. Lampreys are the oldest vertebrate group and thus don’t have jaws, which was the first evolutionary event. All vertebrates that have jaws are called gnathostomes.
  66. Another evolutionary event was of four footed vertebrates, or tetrapods. How was this advantageous?Their limbs could support weight, leading to bigger animals on land.
  67. Amphibians have eggs without a shell and do require water for reproduction.
  68. Amniotes refers to a type of egg. The three things that this contains are what? How was this evolution advantageous?Membranes, fluid and (sometimes) shells. It allowed embryonic development to occur on land by protecting the embryo from water loss.
  69. True or False: Birds belong in the clade Mammalia.False (they belong in Reptilia)
  70. Birds are highly adapted for flight in three ways. What are they? How is flight beneficial?Reduced organ systems (for less weight), airy or “honeycomb” bone structure (for less weight) and feathers (modified scales). Flight was beneficial for exploitation of flying insects, to escape from predators and long-distant migration.
  71. What are the 4 mammalian characteristics that separate them from the rest of the Deuterostomes?Mammary glands (for production of milk), hair, diaphragm (muscle for ventilating lungs) and specialized teeth (for specific eating habits).
  72. There are two major mammalian groups: no placenta and placental. How are they different?In placental mammals, embryonic development is completed within a uterus within the mother’s body.
  73. True or False: Humans and chimpanzees share a common ancestor, meaning humans evolved from chimps.False (the common ancestor means they DIDN’T evolve from chimps)
  74. True or False: Humans and chimpanzees are genetically similar.True