Biology 106 Dr. Dudash
Exam III, FALL 1999
(30 points) TRUE or FALSE. Fill in the blank with the entire word. (2 points each)
1. _FALSE__ Animals invaded land before plants in the evolutionary history of the earth.
2. _TRUE_ Viruses are classified in part by whether they have RNA or DNA.
3. _TRUE__ The first prokaryotes to inhabit the earth almost 4 billion years ago were anaerobes.
4. _TRUE_ Sporic meiosis is another name which describes alternation of generations.
5. _TRUE_ The Permian extinction was the largest mass extinction in the earth's history.
6. _TRUE__ Protista is the most diverse group of Eukaryotic Kingdoms.
7. _TRUE__ All land plants are thought to have evolved from green algae.
8. __FALSE_ Animals, plants and fungi are all derived from the same line of Protists.
9. __TRUE_ Viruses are parasites since they are dependent on a host to replicate.
10. _FALSE_ Horse tails (Equisetum, Sphenophyta) represent a heterosporous seedless vascular plant.
11. _FALSE_ Flagella are homologous between Prokaryotes and Eukaryotes.
12. _FALSE_ Some red algae cause the red tide where autotrophs become carnivores.
13. _TRUE_ Prokaryotes reproduce by binary fission without mitosis and meiosis.
14. _FALSE_ A prion is larger than a viroid and causes liver cancer in humans.
15. _FALSE_ Bacterial cells conjugate mutually to exchange genetic material.
(36 points) Multiple Choice. CIRCLE the answer that best fits the question.
(3 points each)
1) A randomly selected group of organisms from a family would show more genetic variation than a randomly selected group from a
A) class
B) genus ANSWER
C) kingdom
D) order
E) phylum
2) A common ancestor for species C and E could be at position number
A) 1
B) 2
C) 3
D) 4 ANSWER
E) 5
3) Which statement(s) below is NOT TRUE in regards to the evolutionary history of the earth?
A) There is a long history of unicellular life.
B) Modern plants and animals evolved through one event in the earth's history. ANSWER
C) Mass extinctions are important events and follow similar patterns after the extinction events.
D) all of the above
4) In which of the following ways are prokaryotes more successful on earth than humans?
A) Prokaryotes are much more numerous than humans.
B) Prokaryotes occupy more diverse habitats than humans.
C) Prokaryotes often parasitize humans in many ways.
D) Prokaryotes have survived on earth for billions of years longer than humans have
E) all of the above ANSWER
5) The strongest evidence for the endosymbiotic origin of eukaryotic organelles is the similarity between extant prokaryotes and
A) nuclei and chloroplasts
B) cilia and mitochondria
C) mitochondria and chloroplasts ANSWER
D) ribisomes and nuclei
E) ribisomes and cilia
6) Which of the following CORRECTLY pairs a protist group with its' characteristic trait?
A) Apicomplexa: parasitic ANSWER
B) Kinetoplastids: pseudpodia
C) Archaezoa: large single mitochondria
D) Red Algae(Rhodophyta): flagellated life cycle
E) Stramenophila: contains macro and micro nuclei
7) Ways in which Volox has become advanced over Chlamydomonas include which of the following?
A) mature organism is a single haploid cell
B) movement is coordinated among cells
C) colonial organization borders on multicellularity
D) B and C ANSWER
E) A and B
F) A and C
G) all of the above
8) Which of the following is NOT a characteristic of the domain/group Archaea?
A) DNA analyses suggest that Archaea are more closely related to Eukaryotes than Bacteria. ANSWER
B) Some archaeans can readily produce methane while living in marshy habitats.
C) Archaean diversity evolved when the earth was much younger. ANSWER
D) Some archaeans can successfully inhabit nearly saturated salt conditions.
E) Some archaeans can live in water above the boiling point.
9) You are given an unknown organism to identify. It is unicellular and heterotrophic. It is motile, with well-developed organelles and three nuclei, one large and two small. You conclude that this organism is most likely to be a member of which group?
A) water molds
B) ciliates ANSWER
C) euglenoids
D) kinetoplastids
E) rhizopods
10) Bacterial modes of obtaining nutrition used by at least some bacteria include all of the following EXCEPT:
A) chemoautotrophy
B) photoautotrophy
C) heteroautotrophy ANSWER
D) chemoheterotrophy
E) photoheterotrophy
F) all of the above
11) Heterospory refers to the condition of some plants in which:
A) both male and female reproductive organs are found on the same plant.
B) a single individual exhibits two different types of growth.
C) spores are produced twice during the reproductive cycle.
D) different gametes are produced by the same individual
E) two different spore types are produced. ANSWER
12) A group of biology students brings in a small green plant with beautiful red flowers to their Biology TA. They examine the floral and vegetative characteristics and this is what they found. The plant has 4 stigmatic lobes leading to a single ovary, 16 stamens, and exhibits net like branching on the veins of the foliage. Which Angiosperm group does it probably belong to?
A) monocot
B) dicot ANSWER
C) tricot
D) A and B
E) all of the above
(12 points) DEFINE (3 pts.) and EXPLAIN AN EXAMPLE (1 pts.) for each term.
1) Lytic Cycle
OCCURS IN VIRUSES. VIRUS INVADES CELL AND REPRODUCES ITSELF. VIRUS IS DISPERSED WHEN CELL LYSES (= BREAKS OPEN). VIRUS DESTROYS CELL'S DNA AND TAKES OVER THE CELL'S METABOLIC MACHINERY. CELL IS KILLED QUICKLY (THAT IS WHY YOU CAN FEEL SO BAD SO QUICKLY WITH A VIRAL INFECTION).
EX'S, COMMON COLD, POLIO, VIRAL MENINGITIS, AND OTHER
2) Double Fertilization
UNIQUE TO ANGIOSPERMS/FLOWERING PLANTS. {A POLLEN GRAIN GERMINATES AND A SPERM NUCLEI IS RESPONSIBLE FOR THE GROWTH OF THE POLLEN GRAIN TO THE OVARY.: optional} THE POLLEN GRAIN HAS 2 ADDITIONAL SPERM NUCLEI WHERE ONE FERTILIZES THE EGG OR OVULE AND PRODUCES A DIPLOID (2N) ZYGOTE. THE OTHER SPERM NUCLEUS FERTILIZES THE 2 FEMALE POLAR BODIES (NUCLEI) AND PRODUCES A TRIPLOID (3N) ENDOSPERM THAT GOES ONTO TO NOURISH THE DEVELOPING EMBRYO. must have this! underlined
EX., ANY FLOWERING PLANT
3) Era
EVOLUTIONARY HISTORY IS DIVIDED INTO ERAS. THEY ARE DEFINES AS A PERIOD OF TIME MARKED BY DISTINCTIVE CHARACTERISTICS OR OCCURRENCES.
EX'S: ARCHEAN, PROTEROZOIC, PALEOZOIC, MESOZOIC, CENOZOIC
Short Answer In the space provided, supply a concise answer to the following questions.
(22 points)
1) Please diagram an idealistic interpretation (drawing) clearly labeled of Alternation of Generations and provide an example of a group of organisms where the gametophyte stage is dominant AND another where the sporophyte stage is dominant in the life history. (8 points)
GAMETOPHYTE DOMINANT - ANY BRYOPHYTE (1 pt.)
SPOROPHYTE DOMINANT - ANY GYMNO. OR ANGIO. (1 pt.)
TRUE Alternation of Generations
(idealized plant life cycle)
haploid gametophyte (1 N) (1pt.)
spore (1 pt.) egg & sperm
(gametes) (1 pt.)
Gametophyte Generation (n)
--------------------------------------------------
Sporophyte Generation (2n)
(meiosis) (1 pt) (fertilization) (1 pt.)
spor e mother
cells zygote
embryo
diploid sporophyte (2N) (1 pt.)
2) Discuss one of the alternative hypothesis that attempts to explain the evolution of viruses. (4 points)
#1 EXTREME SPECIALIZATION FOR PARASITISM: VIRUSES ARE ORGANISMS THAT HAVE REACHED THE EXTREME IN EVOLUTIONARY SPECIALIZATION FOR PARASITISM. INTERNAL PARASITES COMMONLY "LOSE" UNNECESSARY STRUCTURES THUS VIRUSES MAY BE JUST "REMAINING NUCLEI".
#2 FREE-LIVING NONCELLULAR PREDECESSORS. ANCESTORS OF VIRUSES MAY HAVE BEEN FREE-LIVING AND NONCELLULAR. WHEN THE ORGANIC NUTRIENTS OF THE EARLY PRIMORDIAL SEAS DECREASED THE VIRUSES BECAME PARASITIC ON CELLULAR ORGANISMS TO SURVIVE. THUS MODERN VIRUSES MAY REPRESENT AN EARLY STAGE IN THE ORIGIN OF LIFE.
#3 FRAGMENTS OF GENETIC MATERIAL. THIS IS THE HYPOTHESIS BEING SUPPORTED BY MANY TODAY. THESE VIRAL FRAGMENTS WERE ORIGINALLY DERIVED FROM CELLULAR ORGANISMS. THEY MAY HAVE BEGUN AS BARE NUCLEIC ACID SIMILAR TO VIROIDS AND LATER EVOLVED THE CAPACITY TO INVOKE THEIR HOST CELLS TO SYNTHESIZE A PROTEIN SHELL. FRAGMENTS OF BACTERIAL DNA, PLANT NUCLEIC ACID, HIGHER ANIMALS ARE ALL REPRESENTED IN THE VIRAL GROUP AND THE PECULIAR HOST SPECIFICITY NOTED IN VIRUSES MAY REFLECT THEIR INDEPENDENT EVOLUTIONARY HISTORY (WHERE ORIGINALLY CAME FROM).IT IS THOUGHT THAT VIRUSES INDEPENDENTLY EVOLVED A NUMBER OF TIMES.
3) Discuss the "KEY" to our understanding of the evolution of Prokaryotes. Please include three points associated with the "Key" to our understanding. (4 points)
KEY = RAPID GENERATION TIME (1 POINT)
(1 POINT FOR EACH LOGICAL COMMENT BELOW) :
1-3 HRS COMMON BUT CAN BE AS QUICK AS 20 MINUTES
~ 1 IN 200 BACTERIA WILL HAVE A MUTATION IN THEIR DNA
BILLIONS OF CELLS PRESENT IN A POPLN, THUS MANY MUTANTS POSSIBLE
FREQUENT GENETIC RECOMBINATION, VIA PLASMIDS, VIRUSES VIA CONJUGATION.
MAY BE AN ALTERNATIVE STRATEGY TO SEX
POTENTIAL FOR RAPID CHANGE IN A POPLN W/R TO TRAITS EXPRESSED
4) For each PLANT group and trait please CIRCLE whether the trait is ancestral or derived.
(1 point each for a total of 6 points) * IS CORRECT
1. angiosperm : vascular tissue ANCESTRAL* DERIVED
2. gymnosperms : seeds ANCESTRAL DERIVED*
3. angiosperms : flowers ANCESTRAL DERIVED*
4. ferns : alternation of generations ANCESTRAL* DERIVED
5. bryophytes : waxy cuticle ANCESTRAL DERIVED*
6. ferns : chlorophyll A and B ANCESTRAL* DERIVED