1 / 24

Agenda

Agenda. Today, doing labs 8 and 9a. Informal Lab Report: Due in 1 Week! See the worksheet and insructions last week. Microworlds: 6 new and 4 old Microworlds are due in 2 weeks!! Time to work on it next week, maybe some today depending on your speed today.

Download Presentation

Agenda

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Agenda • Today, doing labs 8 and 9a. Informal Lab Report: • Due in 1 Week! See the worksheet and insructions last week. Microworlds: • 6 new and 4 old Microworlds are due in 2 weeks!! Time to work on it next week, maybe some today depending on your speed today. • Strawberries, onion root & whitefish mitotic slides are available for Microworlds.

  2. Lab 9a: Cell Cycle and Mitosis • Read background in lab carefully • You should get this info in lecture

  3. Cell Cycle: • Interphase: G1, S, G2 • Cell may renter cell cycle or leave cell cycle (G0) • DNA replicated in S • Nuclear division =Mitosis • Cell division =cytokinesis G2 S Mitosis G1 Cytokinesis G0

  4. MITOSIS ANIMATION Actual MITOSIS photography

  5. Lab 9a: Cell Cycle and Mitosis • CELL CYCLE = entire life of cell, including division • Interphase = not dividing • Mitosis = nuclear division • Cytokinesis = cell division

  6. Interphase (before Mitosis) • EVENTS: • G1: Cell grows and prepares to copy DNA • S: Cell copies its DNA • G2: Cell prepares to divide • APPEARANCE: • Chromatin (DNA) not condensed into chromosomes – WHY? • Nuclear envelope present

  7. MITOTIC PHASES • Mitosis • Prophase • Metaphase • Anaphase • Telophase • Cytokinesis

  8. Prophase EVENTS: 1. Chromatin condenses into chromosomes 2. Chromatids visible 3. Nuclear envelope dissolves 4. Centrioles (Spindle fibers) move to opposite poles APPEARANCE: • Nucleus looks blotchy (chromosomes) • Nuclear envelope dissolves

  9. Metaphase EVENTS: • Chromosomes line up in center of cell APPEARANCE: • Dark chromosomes lined up in center of cell • No nucleus

  10. Anaphase EVENTS: 1. Spindle fibers shorten 2. Chromosomes are pulled to opposite poles of cell APPEARANCE: • Two sets of chromosomes visibly separated from each other

  11. Telophase EVENTS: 1. Chromosomes unwind 2. New nuclear envelope reforms APPEARANCE: • Two dark areas of chromatin present at opposite ends

  12. Cytokinesis EVENTS: • Animals: Daughter cells pinch apart at cleavage furrow • Plants: Cell plate forms in center of cell APPEARANCE: • Two new (usually smaller) cells form

  13. Cell Division in Plants Plants differ from animals • Plant cells have no centrioles • Plant cells differ in Cytokinesis: • a cell wall forms between the dividing cells • called a cell plate

  14. Mitosis Review

  15. Lab 9a: Mitosis Ex. 1: Modeling Mitosis with either Clay (1a) or Pop Beads (1b). Only do 1a or 1b. Ex.2: Observing mitosis in plant cell slides • Practice this f/ lab quiz & final! Ex.3: Observing mitosis in whitefish cells • May instead answer which is easier plant or animal? Why? Ex.4: Estimating time spent in each phase

  16. Lab 8, Ex. 4: Estimating the time spent in each phase of Mitosis • Get 3 other people’s data (100 cells total) • Calculate the percent time spent in each phase • (If you have 5 cells/100 in metaphase, then the cells spend ~5% of the time in metaphase.) • Check your answer. If its off, you need to spend more time identify the phases! • Identify the phase for 25 cells

  17. Lab 8, Exercise 1: DNA Extraction • You can extract DNA from practically everything • Strawberries, peas, your lab partner’s brain!

  18. The Lysis Buffer • Contains water and a buffer • A Detergent • to dissolve the membranes so we can extract DNA • The cell wall is not a problem as DNA in water can move through it • A Salt • Causes proteins and carbohydrates to precipitate out of solution • We only want DNA

  19. DNA Extraction • Since your lab partner may object to your isolating brain DNA, we’ll use strawberries • Squash strawberry to increase the surface area exposed to detergent • It simply makes smaller pieces

  20. DNA Extraction • Add lysis buffer and continue squashing • Filter mixture through filter paper (coffee filter) • The DNA will be in the filtrate solution you capture

  21. DNA Extraction • Pour ice-cold alcohol (equal volume to strawberry filtrate) down side of tube to precipitate DNA • Keep it cold!

  22. DNA Extraction • It will appear like slimy snot between the alcohol-water interphase • Skip steps 13-14, viewing your DNA under the microscope.

  23. If desired, here are two Home DNA Extraction sites: • http://www.pbs.org/wgbh/nova/teachers/activities/2809_genome.html • http://biology.about.com/c/ht/00/07/How_Extract_DNA_Human0962932481.htm

  24. Lab8, Exercise 2: Transcription, Translation, Mutation Practice Second base C A U G UAU U UCU UUU UGU Cys Phe Tyr C UAC UGC UCC UUC Ser U UUA UCA Stop A A UAA Stop UGA Leu G UGG Trp UCG UUG Stop UAG U CAU CCU CUU CGU His CUC C CCC CGU CAC Leu Pro Arg C A CUA CCA CAA CGA Gln G CUG CGG CCG CAG First base Third base U AUU ACU AAU AGU Ser Asn AUC lle C ACC AAC AGC Thr A A AUA ACA AGA AAA Arg Lys Met or start G AUG AAG ACG AGG U GUU GCU GAU GGU Asp C GUC GCC GAC GGC G Val Gly Ala A GCA GUA GAA GGA Glu GUG GCG G GAG GGG GAG • Follow directions • Remember base-pairing rules: • DNA  DNA • DNA  RNA • Know how to use this table but do not memorize it!

More Related