Bioe 20B Week 10, Day 1 Photosynthesis/Material Review PDF

ANNOUNCEMENTS THIS WEEK 1. Double Fertilization, Research and Grad School Tuesday, 11/19/24 2. Final project due on Friday, December 6th by midnight! Week 10, Day 1 3. Extra Credit Opportunities: SETS: If 70% of class responds...

ANNOUNCEMENTS THIS WEEK 1. Double Fertilization, Research and Grad School Tuesday, 11/19/24 2. Final project due on Friday, December 6th by midnight! Week 10, Day 1 3. Extra Credit Opportunities: SETS: If 70% of class responds, whole class gets Extra Credit Photosynthesis/ Extra Credit Hike (in-person or virtual) Material Review Bioe 20B Meme 4. Final Exam is on Monday, December 9th, 12:00-3:00 PM Cumulative (Form and Function to Double Fertilization) TODAY’S AGENDA (8-9:35 AM) Double Fertilization TA Maddie McNelis Research Guest Lecture  Another EXTRA CREDIT OPPORTUNITY! Send me your original biology memes!! Get extra credit towards your final exam score by creating an original biology meme based on any of the content we have covered this quarter. 1. Make meme 2. Upload file and submit to “Bioe 20B Memes Extra Credit” Canvas assignment 3. Deadline: Sunday, December 8th by midnight Here are the ground rules: 1) It must be related to the content we have covered this quarter 2) It must be original 3) HAVE FUN!! An example made by Professor Carrillo is attached below: Parasite: Intercepts Parasite: Time to steal the Meanwhile, strigolactone signal from goods fungi… plant Meme created by Joey Schaffer Meme created by Julia Anderson Plant Reproduction  Learning Goals for Today 1 Alternation of Generations 2 Flowers: Development & Triggers of Flowering 3 Gametophytes & Double Fertilization  Alternation of Generations How is reproduction in plants different from reproduction in animals? -In animals the haploid stage is -In plants, the haploid stage is multicellular unicellular (gametophyte) Mitosis Mitosis Mitosis Mitosis -In animals, meiosis produces -In plants, mitosis produces gametes directly (egg, sperm) male and female gametes  Alternation of Generations Why is it called alternation of generations? Plants alternate between two life stages: a haploid gametophyte stage and a diploid sporophyte stage The spores at the end of the arrow are made by the A. Sporophyte B. Gametophyte The spores at the end of the arrow are A. Haploid B. Diploid C. Triploid  Learning Goals for Today 1 Alternation of Generations 2 Flowers: Development & Triggers of Flowering 3 Gametophytes & Double Fertilization  Why did sexual reproduction evolve in flowering plants (angiosperms)? 300,000 sp! (80% of all plants) Sexual reproduction evolved because it is a selective advantage of producing genetic diversity. Involves mitosis, meiosis, and alternation of haploid and diploid generations Label as many parts of the flower as you can! Carpel Stamen Petals Sepals Anther Stigma Receptacle Ovary Filament Style  Form, Function, Development of Flowers Anther Stigma Petal Stamen (male parts) Carpel Style (Female Ovary Filament parts) Ovule Receptacle (Inside) Sepal  Form, Function, Development of Flowers Flowers can be (Stamen) (Carpel) “perfect” = both male and female Roses, lilies, tulips, parts on same flower hibiscus, carnations = both male and female Monoecious Corn, begonias, flowers on same plant squash, pines (1 house) Dioecious = male and female flowers Willows, holly, on different plants hemp, spinach (2 houses)  Form, Function, Development of Flowers Type “Perfect” Monoecious Dioecous both male and female male and female flowers both male and female on different plants Description flowers on same plant parts on same flower (2 houses) (1 house) Roses, lilacs, Corn, begonias, Willows, holly, Examples carnations, lilies squash, pines hemp, spinach Drawing  Form, Function, Development of Flowers Stamen (male parts) A flower that was missing the structure in red would be a A. Perfect, male flower Carpel B. Perfect, female flower (Female C. Imperfect, male flower parts) D. Imperfect, female flower Form, Function, Development of Flowers What type of flower is this? A. Perfect B. Monoecious C. Dioecious Both male and female flowers on same plant (squash) Form, Function, Development of Flowers What type of flower is this? A. Perfect B. Monoecious C. Dioecious Both male and female parts on the same flower (wild rose)  Form, Function, Development of Flowers 1) How does the flower develop? - Vegetative apical meristem becomes an inflorescence meristem ? becomes floral meristem - Organ identity genes determine floral organs Vegetative Reproductive growth growth that are expressed  Form, Function, Development of Flowers poinsettias What are some factors that trigger flowering? Environmental – day length, temperature sunflowers phytomer broccoli Internal – Size (number of phytomers) Form, Function, Development of Flowers 4 organs of a flower: Sepals Arranged in Petals whorls Stamens around Carpels central axis Form, Function, Development of Flowers 4 organs of a flower: Sepals Petals Stamens Carpels  Form, Function, Development of Flowers Anther Stigma Stamen Style Petals (male parts) Carpel Ovary (Female Ovule Filament parts) (Inside) Sepals  Form, Function, Development of Flowers How do the whorls get determined? Organ identity genes Three classes of genes: A, B, C Each codes for one half of a dimer transcription factor Note that we can’t combine BB and AC… Can get several combinations which AA, AB, BC, CC code for different organs: sepals petals stamens carpels  1 2 4 3 Different combinations of genes get expressed in each CC BC AB AA whorl = different organs are made in each whorl!  Why don’t A and C fit together? What about B and B? Transcription factors fit together like pieces to a puzzle… A B C Sepal Stamen A A B C A C Petal Carpel A B C C B B  5-min Break! Attendance Time Scan the QR code or go to https://tinyurl.com/W10D1plantreproduction to answer the following question: Q: What is the difference between "perfect" flowers, monoecious and dioecious plants? (This will be used for taking attendance today.)  Learning Goals for Today 1 Alternation of Generations 2 Flowers: Development & Triggers of Flowering 3 Gametophytes & Double Fertilization 1) Pollen grain Stigma 2) Style Form, Function, Development of Flowers Double Fertilization 3) 4) and 5) Now endosperm (3N) Now zygote (2N) (Send out signal to tube cell) 1) Pollen grain lands on stigma 4) 1 sperm fuses with egg =(2N) (zygote) 2) Tube cell grows down style 5) 1 sperm fuses with BOTH 3) Generative cell mitotically divides central nuclei (3N) à Endosperm = Provides into 2 sperm nutrients to zygote  Form, Function, Development of Flowers Double Fertilization What is the role of synergids in double fertilization? Synergids send out chemical signal for directing pollen tube to egg Pollen tube VIDEO The pollen tube is the fastest growing cell! Why do you think this is? There is selection for speed in pollen tube growth since first to arrive, gets to fertilize! What plants have double fertilization? Angiosperms (flowering plants) What does the “double” part refer to? Involves 2 sperm: 1 fertilizes egg; 1 joins with central nuclei and becomes endosperm What does the endosperm do? Provides nutrients for zygote to become seedling B Where is the endosperm found? In the seed A What tissue is triploid? Endosperm (sperm joins with 2 nuclei) Endosperm is: A or B  Gametophyte gametophyte is 1N and makes the __________________. In plants the ________________ gametes Sporophyte Gametes embryo sac In angiosperms, the female gametophyte is the _____________ and is contained in the flower. Spores Embryo Sac pollen grain and is contained in the flower. In angiosperms, male gametophyte is the ____________ Pollen Grain Ovule Anther Carpel Stamen FEMALE GAMETOPHYTE: Embryo sac = megagametophyte Develops inside the ovule MALE GAMETOPHYTE: Pollen grain = microgametophyte Develops in the anther  Key Points Double fertilization refers to the fact that two sperm are involved in fertilization: 1 sperm fertilizes the egg while the other joins with the diploid polar nuclei to form the endosperm Endosperm is used by the developing plant to fuel growth before it begins photosynthesis Only angiosperms have double fertilization Eggs and sperm are made through MITOSIS not MEIOSIS  Kahoot Review: Plant Reproduction