Name _________________ HS 301 Exam 1 September 12, 2014 Please read each question carefully. Answer thoroughly but succinctly. 1. (10) Using all of the following words, compose a coherent and biologically informative paragraph: periclinal chimera, adventitious, seed propagation, axillary bud, root cutting, terminal stem cutting, grafting, sub-terminal stem cutting, leaf cutting, non-adventitious growing point, division, variegated phenotype. PERICLINAL CHIMERAS, SUCH AS A VARIEGETED LEAF PHENOTYPE CAUSED BY CHIMERISM, CAN ONLY BE FAITHFULLY PERPETUATED VIA PROPAGULES THAT CONTAIN A NON-ADVENTITIOUS GROWING POINT, SUCH AS TERMINAL STEM CUTTINGS, SUBTERMINAL STEM CUTTINGS CONTAINING AN AXILLARY BUD, DIVISION, OR VIA GRAFTING. PERICLINAL CHIMERAS CANNOT BE PROPAGATED BY SEED, OR VIA ANY PROPAGATION TECHNIQUE THAT RELIES ON ADVENTITIOUS SHOOT PROLIFERATION, SUCH AS ROOT CUTTINGS, AND LEAF CUTTINGS. 2. (5) In class, I showed a picture of my favorite candy, a "Peanut M & M". In what context did I show this, and briefly elaborate on the analogy of the M & M to the biological structure discussed. THIS CANDY IS AN EXCELLENT ANALOGY TO DEMONSTRATE THE 3 HISTOGENIC LAYERS IN THE MERISTEM OF HIGHER PLANTS. 3. (4) How might the wild progenitor of corn, Teosinte, differ from the domesticated corn of today in some aspect of reproductive biology? Use the relevant terminology. TEOSINTE DEMONSTRATED SHATTERING SEED, MEANING ITS SEED WERE DISSEMINATED FROM THE MOTHER PLANT AT MATURITY. MODERN GRAIN CROPS HAVE BEEN SELECTED TO RETAIN THEIR SEED AT MATURITY, A TRAIT REFERRED TO AS "NON-SHATTERING". 4. (3) Provide the name of the horticultural domesticated plant (common name ok) that arose as a consequence of chance hybridization between 2 species in a garden in France. __STRAWBERRY____________ 5. (4) Please state the 4 important determinants in the "HS301 approved" definition of a clone. KNOW THIS! A GROUP OF PLANTS GENETICALLY IDENTICAL DERIVED FROM A SINGLE PLANT OR PLANT PART PROPAGATED ASEXUALLY6. (3) Distinguish between "pasteurization" and "sterilization". PASTEURIZATION IS TREATMENT AT 160-180F, ALLOWING RETENTION OF SOME MICROBIAL ACTIVITY. STERILIZATION IS AT TEMPERATURES OF 212 OR HIGHER, TYPICALLY AROUND 245-250 FOR MICROPROIPAGATION MEDIA. SUCH TREATMENT ELIMINATES ALL MICROBIAL ACTIVITY. 7. (5) Explain the terms "monoculture" and "genetic vulnerability". Provide a past horticultural example of genetic vulnerability. MONOCULTURE REFERS TO THE USE OF ONE MAJOR CLONE OR CULTIVAR IN AN AGRICULTURAL PRODUCTION SETTING. GENETIC VULNERABILITY REFERS TO THE ENHANCED RISK OF A MAJOR DISEASE OR INSECT OUTBREAK AS A CONSEQUENCE OF THE LIMITED GENETIC VARIABILITY INHERENT IN A MONOCULTURE SETTING. 8. (4) What is a major difference in "reproductive options" between higher plants and higher animals? HIGHER PLANTS CAN PROPAGATE ASEXUALLY WITH RELAIVE EASE, BUT HIGHER ANIMALS CANNOT. ALSO, HIGHER PLANT CLONES ARE VIRTUALLY IMMORTAL THROUGH NUMEROUS CYCLES OF ASEXUAL PROPAGATION. HIGHER ANIMALS HAVE A LIMITED LIFE SPAN AND DEMONSTRATE AGING. CLONES DO NOT AGE IN THE CLASSICAL SENSE. 9. (4) What is interesting about the "trigger" for phase transition in the common ornamental ivy, Hedera helix? PHASE TRANSITION IS TRIGGERED BY PLANT ORIENTATION. WHEN A JUVENILE PLANT CHANGES ORIENTATION BY CLIMBING UP A STRUCTURE, THIS TRIGGERS THE TRANSITION TO ADULT PHASE. 10. (6) What species (common name) of tree is shown in this image, and briefly elaborate on the principle or concept that this image demonstrates. Why might forestry researchers manage plants this way?SHOWS LOBLOLLY PINE BEING HEDGED TO MAINTAIN JUVENILE PHASE FOR ASEXUAL PROPAGATION PUYRPOSES. 11. (5) What concept is demonstrated by the 3 images shown below? (write answer to the right of the images). Do you remember the name of this plant?THIS SHOWS HOW A UNIQUE PLANT THAT IS FOUND IN NATURE CAN BE ASEXUALLY PROPAGATED AND DEPLOYED QUICKLY IN LARGE NUMBERS INTO COMMERCE AS A CLONE VIA THE USE OF ASEXUAL PROPAGATION, IN THIS CASE GRAFTING. THIS IS 'SLENDER SILHOUETTE' SWEETGUM. 12. (3) Provide 2 reasons why we might choose asexual propagation over seed propagation? MAINTAIN UNIQUE CHARACTERISTICS OF THE PLANT THAT ARE NOT SEED TRANSMISSABLE, SUCH AS A CHIMERA. ALSO, TO PROPAGATE PLANTS THAT ARE SEXUALLY STERILE. 13. (4) Name both an advantage and a disadvantage of taking cuttings from the adult phase of a woody, ornamental plant that has a long juvenility period. ADVANTAGE IS THAT THE PLANT WILL FLOWER AND FRUIT MORE QUICKLY THAN IF DEPLOYED BY SEED. DISADVANTAGE IS THAT CUTTINGS FROM ADULT PHASE GROWTH ARE OFTN DIFFICULT TO PROPAGATE VIA STEM CUTTINGS. 14. (2) We refer to the time between mist cycles in a propagation bed as the ____INTERVAL____________, while the length of time the mist is applied when the system is operative is called the ___DURATION________________. 15. (2) The term used to describe cell division ___MITOSIS_______________ 16. (2) About 50% of the carbon fixed on this planet is fixed by land plants. The other 50% is fixed by _____PHYTOPLANKTON________________________. (be specific here). 17. (2) Dwarf apple trees are made possible as a consequence of this propagation technique? ___GRAFTING________________ 18. (2) A lateral branch that shows a different phenotype (appearance) than the remainder of the plant to which it is attached is called a _______BUD SPORT_______________________ 19. (2) Anthropologists estimate that humans have been involved in agriculture for about __10,000____________ years.20. (2) One potential negative consequence of the use of “non-domesticated” plants in Horticulture. ____INVASIVE POTENTIAL____________________ 21. (3) The name of the valve that is plumbed into the water line that controls the on/off function of a mist propagation facility. ____SOLENOID___________________ 22. (2) The "texensis" form of redbud represents a phenotypic variation of eastern redbud that occurs in nature. Hence, Texas redbud is referred to in