Final 2018, questions and answers PDF

Preview

Summary

Professor: Greg Beaulieu...

Description

Bio Qs: FUNGI: Why are fungi filamentous? increased SA for absportion of nutrients Dikaryon cell with 2 haploid nuclei, contains 2 chromosome sets like a diploid cell Basidiomycte life cycle1n mycelial growth, dikaryon formation, n+n mycelial growth, basidiocarp formation, basidium formation, karyogamy, meiosis, basidiospore formation Hypha branched filament Mycelium mass of hyphae What fungal life cycle feature and dispersal accounts that food will spoil? Tons of spores, reach everywhere, waiting to germinate MC: Consider two hyphae having equal dimensions: one from a septate species and the other from a coenocytic species. Compared with the septate species, the coenocytic species should have a. fewer nuclei. b. more pores. c. less chitin. d. less cytoplasm. e. reduced cytoplasmic streaming. INTRODUCTION TO ANIMAL DIVERSITY What is the significance of bilateral symmetry? associated with cephalization, deal w threats Homeotic genecontrols identity of body parts Hox genecontains homeobox (certain DNA sequences), characteristics of animals Do acoelomatous worms have a blood vascular system? no, mesoderm forms solid cell mass, no room for differentiation of organs What differs an animal from a alga? animals are multicellular, lack cell walls, wormlike Why do animals have intercellular junctions unlike algae, plants and fungi? multicellularity evolved independently after divergence occurred. Sample Multiple Choice Questions What is the probable sequence in which the following clades of animals originated, from earliest to most recent? 1. tetrapods 2. vertebrates 3. deuterostomes

4. amniotes 5. bilaterians A. 5 → 3 →2 → 4→ 1 B. 5 → 3 →2 → 1→ 4 C. 5 → 3 →4 → 2→ 1 D. 3 → 5 →4 → 2→ 1 E. 3 → 5 →2 → 1→ 4 What distinguishes a coelomate animal from a pseudocoelomate animal is that coelomates A. have a body cavity, whereas pseudocoelomates have a solid body. B. contain tissues derived from mesoderm, whereas pseudocoelomates have no such tissue. C. have a body cavity completely lined by mesodermal tissue, whereas pseudocoelomates do not. D. have a complete digestive system with mouth and anus, whereas pseudocoelomates have a digestive tract with only one opening. E. have a gut that lacks suspension within the body cavity, whereas pseudocoelomates have mesenteries that hold the digestive system in place. Which of the following is descriptive of protostomes? A. spiral and indeterminate cleavage, blastopore becomes mouth B. spiral and determinate cleavage, blastopore becomes mouth C. spiral and determinate cleavage, blastopore becomes anus D. radial and determinate cleavage, blastopore becomes anus E. radial and determinate cleavage, blastopore becomes mouth At which developmental stage should one be able to first distinguish a diploblastic embryo from a triploblastic embryo? A. fertilization B. cleavage C. gastrulation D. coelom formation E. metamorphosis INVERTEBRATES What sponge cells suggest an evolutionary affinity with choanoflagellates? Choanocytes (collar cells) What are the function of the mollowing molluscan structures? a Footlocomotion, attachment, burrowing b Mantle cavitylocation of gills, anus, modified lung in terrestrial gastropods c Mantlesecretes shell, protects visceral mass d Radulatooth scraping tool to scrap food from rocks or drilling into shells How does arrangement and contraction of muscles in an earthworm generate movement? circular and longitudinal muscles lengthens segements, Bristles (chaetae) anchor segment at new spot, circular muscles relax, longitudinal muscles contract, rest of body dragged up.

What is the function of hard arthropod exoskeleton? protect and anchorage in marine, prvent water loss, support against gravity in terrestrial Why are arthropod appendages striking examples of evolutionary homology?flexible appendages (wlaking, sensing, feeding (mandibles), defense, food capture, sexual reprod, diff number of appendages) Hemoglobin transports oxygen in chordate and Annelida, as old as Burgess Shale in Cambrian explosion The bodies of many sponges contain finely branched channels through which water is propelled. What is the advantage of this branching? channels lined with choanocytes, absorb food, more channels=more choanaocytes for phagocytosis, water slows down in branches, more time to eat Jellyfish are diploblastic animals, and consequently lack mesoderm and true muscle. And yet jellyfish can move in the water (albeit weakly). How do they do it? elongated contractile cells in epidermis/gastrodermis, anchored in mesoglea, provide movement, cannot be considered muscle tissue bc not serived from mesoderm Planarians are negatively phototactic. What does this mean, and why is this ability an advantage? move away from light to avoid being seen Tapeworms do not have a gut or gastrovascular cavity. How do they live without one? endoparasitic, nutrients digested by host, able to absorb across body wall The penis fencing contests in which some flatworms engage – contests which sometimes result in the death of one of the combatants – would not appear to be in the best interests of the species. How, then, could such behavior have evolved?-->all that matters is that genetic variants allow possessor to reproduce. Suggest a function of chromosome diminution in nematodes accelerate DNA replication, division and development, advantage for small prey to reproduce as quickly as possible Why is Caenorhabditis elegans a good model for developmental genetics? small, rapid generation time, lineage of every cell is known. Round worm DEUTEROSTOMES What important attribute does sea star have in common with a) a cnidarianradial symmetry in adulthood b) a monkeydeuterostome development What is the difference, structurally, between a notochord and a vertebral column? notochord, solid continuous structure, vertebral column, composed of chunks of bone/cartilage What advantage does a notochord confer to larval forms that have one? allows for whole body swimming motion, allows larva to grow bigger than larva propelled by cilia

Which extant fishes and fishlike forms have retained a cartilaginous skeleton as an ancestral condition, and which have acquired it after the secondary loss of a bony skeleton? Retained: hagfish, Loss of bony: chondrichthyes, some bony fish How do you think the size of an amphibian might relate to its ability to take up oxygen through its skin? larger animal, lower SA, less efficient therefore amphibians limited in size What adaptations liberated reptiles from the dependence on moist habitats that restricts the range of amphibians? amniotic eggs and dry skin with keratinized scales What is the relationship between endothermy and body insulation? insulating fat/fur helps endothermy Much about the structure and metabolism of birds is explained by the demands of flight. What are these adaptations? lighter skull, wings, endothermy toothless beaks, 4 chambered heard, air sacs over lungs (unidirectional), keel on sternum What are the distinguishing features of mammals? mammary glands, fur, endothermic, 4 chambered heart, differentiation of teeth, jaw bones in inner ear What are the differences between monotremes, marsupials, and placental mammals? Monotremes lay eggs, females have no nips (fur milk) Marsupials born before fully developed, later development occurs in pouch Placental  complete development in uterus, nourished by placenta, strong connection from mother to young A sponge's structural materials (spicules, spongin) are manufactured by the A. pore cells. B. epidermalcells. C. choanocytes. D. amoebocytes. E. neoblast tissue Against which hard structure do the circular and longitudinal muscles of annelids work? A. bristles B. cuticle C. shell D. endoskeleton E. hydrostaticskeleton What would be the most effective method of reducing the incidence of blood flukes in a human population? A. reduce the mosquito population B. reducethefreshwatersnailpopulation

C. purify all drinking water D. avoid contact with rodent droppings E. carefullywashallrawfruitsandvegetables In a tide pool, a student encounters an organism with a hard outer covering that contains much calcium carbonate, an open circulatory system, and gills. The organism could potentially be a crab, a shrimp, a barnacle, or a bivalve. The presence of which of the following structures would allow for the most certain identification of the organism? A. a mantle B. a heart C. a body cavity D. a filter-feeding apparatus E. eyes Which structure do nudibranchs use to feed on their prey? A. nematocysts B. a sharp beak C. an incurrent siphon D. a radula E. a mantle cavity Arrange these terms from most inclusive (most general) to least inclusive (most specific). 1. lobe-fins, 2. amphibians, 3. gnathostomes, 4. osteichthyans, 5. tetrapods. A. 4, 3, 1, 5, 2 B. 4, 3, 2, 5, 1 C. 4, 2, 3, 5, 1 D. 3, 4, 1, 5, 2 E. 3, 4, 5, 1, 2 Phylum Porifera Phylum Cnidaria Medusozoa Hydrozoa Scyphozoa Cubozoa Anthozoa Phylum Platyhelminthes Turbellaria Trematoda Cestoda Phylum Mollusca Polyplacophora Gastropoda

Bivalvia Cephalopoda Phylum Annelida Errantia Sedentaria Earthworms Leeches Phylum Nematoda Phylum Arthropoda Chelicerata Arachnida Myriapoda Diplopoda Chilopoda Pancrustacea Hexapoda (Insecta) Crustacea Phylum Echinodermata Asteroidea Ophiuroidea Echinoidea Crinoidea Holothuroidea Phylum Chordata Cephalochordata Urochordata Vertebrata Myxini Petromyzontida Chondrichthyes Actinopterygii Actinistia Dipnoi Amphibia Reptilia Mammalia

TERMS Actinopterygii agnatha

amniota bilateria centipedes ecdysozoa eumetazoa gnathostome lophotrochozoa mandibulates millipedes osteichthyes parazoa radiate tetrapoda 1. __________ occurs when a bee carries pollen from one population of plants to another population of the same species in a different location. A. Gene flow B. A population bottleneck C. The founder effect D. Natural selection E. Random mating 2. Populations of a European clover, Trifolium repens, produce cyanide, which increases their resistance to herbivores such as mice and slugs; however, it also increases their susceptibility to frost. Populations from northeast Europe produce relatively little cyanide compared with populations in southwest Europe. This is an example of _____________________________ A. genetic drift. B. a cline. C. allopatric speciation. D. reproductive isolation. E. gene flow. 3. Individuals with darker or lighter body colour survive better than flies with intermediate body colour. The type of natural selection operating on this fly species is A. directional selection. B. nonrandom selection. C. disruptive selection. D. stabilizing selection. E. sexual selection. 4. If an allele is defined in terms of DNA sequence, and not in terms of easily- observed features of phenotype (like Mendel’s alleles), how many alleles would exist in the human population for a typical human gene? A. two or three B. around ten C. fifty or so

D. not more than one hundred E. hundreds to thousands 5. Which of the following correctly distinguishes between characters and traits? A. Characters are the more common features; traits are rare mutants. B. Organismal functions (in animals) are characters; behavioural features are traits. C. Characters are specific values of a trait. D. Fur colour in dogs would be an example of a character; black fur and brown fur would be traits. E. Characters are determined genetically and are inherited; traits are determined by the environment and are not inherited. 6. What is one important implication of the Hardy-Weinberg equilibrium law? A. Sexual reproduction by itself brings about changes in the genetic structure of populations. B. A non-evolving population will ‘drift’, so to speak, toward higher levels of average fitness. C. In an evolving population, all the causative agents of evolution will eventually cancel each other out, leading to a period of stasis. D. Allelic frequencies will reach equilibrium values as long as there is no mutation. E. Recessive alleles have no inherent tendency to disappear from a population. For Questions 7 – 9, use the following list of barriers to reproduction to describe these situations. A. temporal barrier B. behavioural barrier C. mechanical barrier D. habitat barrier E. gametic barrier 7. a species of insect lives and mates only in and around a lake; a related insect lives and mates in the upper branches of trees surrounding the lake D. Habitat 8. two species of nematodes have incompatible genitalia C. mechanical 9. an egg cell and a sperm cell do not have the receptors on their surfaces that are able to recognize each other E. gametic 10. Which of the following genotypes is (are) homozygous? A. RR and rr B. RR only C. rr only D. Rr only E. RR, Rr and rr 11. Mendel’s principle of segregation has, as its physical basis, events in A. prophase I of meiosis. B. metaphase I of meiosis.

C. anaphase I of meiosis. D. telophase of mitosis. E. cytokinesis. 12. Why do apes such as chimps and gorillas have 48 chromosomes, while humans have only 46 chromosomes? A. We don’t need that many chromosomes, since many genetic functions needed by animals living in the wild are no longer needed by people. B. We have lost a pair of homologues from our genome. C. Apes have acquired more chromosomes by chromosome-splitting events. D. In the time since our common ancestor with chimps, there was a fusion of chromosomes 12 and 13 to give human chromosome 2. E. Apes have extra chromosomes due to some long-ago mistake in meiosis, which explains why they are not as intelligent as we are. 13. Suppose that, in mice, the Q allele encodes a protein needed in embryonic development. A recessive deletion allele, q, fails to produce a functional protein, and, when the allele is homozygous, is lethal to the embryo very early in life. If two heterozygous mice mated and produced offspring, what fraction of the offspring that are born will be carriers of the recessive allele? A. all of them B. 1/4 C. 1/3 D. 1/2 E. 2/3 14. The statement that evolutionary change has happened and continues to happen has the status of _____________ in science. A. hypothesis B. guess C. fact D. speculation E. conspiracy 15. In contrast to many models of inheritance in the nineteenth century, Mendel’s work implied that inheritance is A. fluidlike. B. particulate. C. prone to environmental influences. D. affected by the experiences of the parents during their lives. E. due to DNA molecules. 16. Which of the following causes of evolutionary change is consistently adaptive? A. mutation B. natural selection C. genetic drift D. nonrandom mating E. gene flow 17. Why does genetic drift often have maladaptive consequences for a population? A. It can result in the reduction of genetic variability in a population.

B. It can cause mutation rates to rise. C. It can reduce gene flow from neighbouring populations with better-adapted alleles. D. It can curtail the operation of natural selection. E. It can disturb the Hardy-Weinberg equilibrium. 18. If a population is in Hardy-Weinberg equilibrium, and one of the two alleles of a gene has a frequency of 0.4, what is the frequency of the heterozygotes? (You should be able to do this question without a calculator.) A. 0.48 B. 0.16 C. 0.24 D. 0.36 E. impossible to tell from this information 19. Concerning the population in the previous question, if it is NOT in Hardy- Weinberg equilibrium, and one of the two alleles of a gene has a frequency of 0.3, what is the frequency of the heterozygotes? A. 0.42 B. 0.09 C. 0.49 D. 0.21 E. impossible to tell from this information 20. What is the criterion biologists favour for distinguishing one species from another, if that criterion is applicable? A. physical similarity B. ability to reproduce and produce fertile offspring C. filling the same ecological role D. living in the same area E. living in the same habitat...