Plants Sessile vs Motile Are plants sessile or motile? Imagine you are sessile like a plant, what would be different / hard for you to do?
Plant Reproduction Plants use both sexual and asexual reproduction. In plants, asexual reproduction is sometimes referred to as vegetative reproduction. A. Stolon or runner above ground stem Ex. strawberry B. Rhizome Underground stem Ex. ginger, asparagus C. Sucker, Upright shoot coming from horizontal root Ex. Aspen
Asexual reproduction D. Bulb Ex. onion, tulip All living species have developed strategies, behaviors, and structures to increase the chances of successful reproduction. Life first evolved in water Plants evolved various adaptations to allow them to grow on land.
Moss How does the sperm reach the egg? swims (or splashes) Fertilization ---> zygote Where does moss tend to grow? Wet environments Moss in a Japanese garden https://file.scirp.org/pdf/oje_2018031915033102.pdf Pollination https://www.ted.com/talks/louie_schwartzberg_the_hidd en_beauty_of_pollination/transcript?language=en
Flowering plants (and gymnosperms) Pollen - Adaptation Allows sperm to survive dry conditions Protects sperm Allows sperm to travel long distances Wind animals
A Close-up View of the "Peruvian Lily"(Alstroemeria psittacina) http://www.microscopy-uk.org.uk/mag/artoct08/bj-peru.h tml
Alstromeria stigma Photo credit: David Illig https://www.flickr.com/photos/primeval/67 90299306/in/photostream/ Do Now Read p 25-26 and answer p 23 in packet *See if you can find the errors in the top of p23*
Discuss: P 21 last question: Why prevent self-pollination?
Wind pollinated plants Small, dull flowers No smell Lots of pollen Wind pollinated plants corn and other grasses, trees Produce huge amounts of pollen
https://ipm.missouri.edu/ip CM/2012/7/Corn-Pollinatio n-the-good-the-bad-and-t he-ugly-pt-2/ Cross pollination 1.
Cross pollination Pollen is 1. produced in the anther The pollinator gets covered in pollen while it is drinking nectar. 1. stigma Pollen sticks to the sticky stigma while the pollinator drinks nectar from the second flower.
1. Pollen tube grows through style to ovary Fertilization: Sperm is released in ovary and fuses with egg zygote Pollinator Pathways Pollinator pathway - CT, NY https://www.pollinator-pathway.org/about Bedford 2020 Pollinator friendly solar http://bedford2020.org/pollinator-friendly-solar/
ovary Fruit = mature ovary http://tomatosphere.letstalkscience.ca/resources/library/articleid/4767/the-life-cycle-of-a-tomato-plant.aspx Tomato Life Cycle Fruit seed http://tomatosphere.letstalkscience.ca/resources/library/articleid/4767/the-life-cycle-of-a-tomato-plant.aspx
Corn- embryo Time lapse corn germination https://www.youtube.com/watch?v=ifcdagemgoa Plants are sessile 1. Pollination a. Wind b. Animal c. Water 2. Seed dispersal (Plant embryos are inside of seeds) a. Wind b. Animal c. Water
Seed Dispersal Dandelion seeds reveal newly discovered form of natural flight https://www.sciencedaily.com/releases/2018/10/18101714 0942.htm Seed Dispersal Coconut (water) Hooks and barbs on animal fur (animal) Maple helicopters (wind) Deer eating apple (animal)
One seed may grow into a tree. One tree can produce one hundred thousand flowers each year. Each flower can produce one hundred thousand grains of pollen. -Hope Jahren, Lab Girl p 204 How many grains of pollen can result from one tree in one year? 99.9% of the pollen does not reach a stigma Of the many million seeds dropped each year, less than 5 percent will begin to grow. Of those, only 5 percent will survive to their first birthday. P234 Lab Girl Talk about what would happen if all of these survived.
Corn - silks - Each one is a style and stigma Animal-pollinated plants (bee, moth, butterfly, bird) vs. Wind-pollinated plants
Some people are allergic to pollen Usually allergic to pollen from wind-pollinated plants Huge amounts of pollen released Very light. Can travel over 1000 miles. Extra material: For strategies - Masting of trees - and cycles of squirrels, etc - less likely that the seeds will all be eaten. Inch high pecan might have 6 feet of root One hop hornbeam catkin holds several million grains of pollen
Much more than 99.9 percent of pollen produced in the world goes absolutely nowhere and fertilizes nothing. Lab Girl p203