Week 9 Notes: Lectures 17&18
Week 9 Notes: Lectures 17&18 HORT 1001
U of M
Popular in Plant Propagation
Popular in Agriculture and Forestry
verified elite notetaker
This 0 page Class Notes was uploaded by Abbie on Wednesday November 11, 2015. The Class Notes belongs to HORT 1001 at University of Minnesota taught by Thomas Michaels in Fall 2015. Since its upload, it has received 14 views. For similar materials see Plant Propagation in Agriculture and Forestry at University of Minnesota.
Reviews for Week 9 Notes: Lectures 17&18
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 11/11/15
Lecture 17Mitosis Ploidy of sets of identical chromosomes in a cell 0 When cells contain one set of chromosomes haploid n 0 When cells contain two sets of chromosomes like in a zygotediploid 2n 0 Endosperm cells have three sets of chromosomes 2 from female one from maletriploid 3n Somatic cells like most of the cells of owering plants we39ve learned about so far ie epidermis cortex vascular tissue are diploid 2n 0 Each cell has two sets of chromosomes 0 Each diploid cell has two copies of chromosomes 1 2 copies of chromosome 2 and so on Homologs matching chromosomes from the two different sets 0 Sequence of pairs can be different 0 Cell in plant39s apical meristemsdiploid Synthesis Chromosomes make an exact copy of itself 61 S 62 lnterphase Sister chromatids remain connected at the centromere Stages of Mitosis lnterphase o Chromosomes relaxed rather than highly condensed 0 Sister chromatids ARE NOT homologs Prophase o Chromatin begins to condense into chromosomes 0 Spindle apparatus begins to appear microtubules associated with movement of the chromosomes during division Metaphase o Spindle forms attachments to the sister chromatids at the centromere kinetochore 0 Sister chromatids move to the metaphase plate which is formed along the midline of the cell between the poles 0 Sister chromatids are in their most condensed state Anaphase 0 Sister chromatids begin to separate one migrates to one pole other migrates to opposite pole they are now chromosomes 0 Chromosomes carrying DNA code are divided precisely Telophase o Cytokinesis occurs nuclear membrane forms around chromosomes in each of daughter cells cell plate forms between the two daughter cells and cell walls separate the newly formed cells 0 Chromosomes decondense and become relaxed chromatin 0 Three keys to understanding how you get two cells from one 1 DNA is completely replicated during S stage of interphase 2 As the cell prepares to divide the DNA condenses 3 The process is very organized Lecture 18Grafts and Wounds Grafting a set of techniques used for joining together two or more plant parts from different plants so they appear to grow as one Creates a chimera two different genotypes are growing together on the same plant Scion top and rootstock bottom 0 Reasons to Graft o Creates unique commercially desirable ornamentals o Perpetuate desirable genotypes of plant types that are notoriously tough to root 0 Changes varietiescultivars o Producing trees with specialized forms such as a weeping habit drooping branches 0 Increases growth rate of seedlings 0 Repairs damaged plants 0 Takes advantage of rootstock characteristics 0 Reasons Against Grafting o Requires experience in technique 0 There must be a good reason to graft and no easiercheaper way to accomplish the same ends Wood Healing What occurs when you do a stem cutting 0 Cells along the cut surface are sliced open die and become dead Ussue o Surviving cells one layer in from the cut respond by either Rapidly expel compounds to protect plants from extreme water loss and invasion of diseases and insects hours Stimulated to divide and produce a mass of new cells callus to cover and protect wounds years In Grafts 0 Cell division starts and callus forms 0 Callus from the rootstock and scion grow together to form a callus bndge o Parenchyma differentiates into cambium cells 0 Cambium then creates new xylem and phloem 5 Requirements for Successful Graft o Rootstock and scion must be compatible Cambium layers of scion and rootstock must be closely aligned Graft must be done at the appropriate time Grafts must be protected from drying Grafted plants must receive proper postgraft care 0000 Examples of Grafting in Food Plants Apple Grapes Vegetables 0 Apple trees usually grown with dwar ng rootstock to make them easier to harvest Grapes use resistant rootstocks to protect the plants from phylloxera Rootstock in veggies also helps to avoid diseases
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'