LIFE 103 Week 4 Notes
LIFE 103 Week 4 Notes LIFE 103
Popular in Macrobiology; Plants and Animals
verified elite notetaker
Popular in Biology
This 5 page Class Notes was uploaded by Lauren Caldwell on Friday February 12, 2016. The Class Notes belongs to LIFE 103 at Colorado State University taught by Erik Arthun, Tanya Dewey in Spring 2016. Since its upload, it has received 21 views. For similar materials see Macrobiology; Plants and Animals in Biology at Colorado State University.
Reviews for LIFE 103 Week 4 Notes
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: 02/12/16
2/8 Chapter 30 - Seed Plants - Gymnosperms (exclusively; excluding angiosperms) Gymnosperm = "naked + seeds" A seed is made up of an embryo and the nutrients that surround it in a protective coat o They can now be dispersed over long distances by several means Does not require water in order to become a fertilized embryo Gametophyte actually shrank - is microscopic for these guys Seeds and pollen grains adaptations for life on land o All seed plants have: Reduced gametophytes (are MICROSCOPIC) Advantage? The gametophytes develop within the walls of spores and then are kept within the tissues of the parent plant The gametophytes themselves are now protected from environmental stresses, as well as are fed by the parent Are no longer independent - helps the gametophyte develop When I say 'independent,' I literally mean was separate Heterospory Can develop into male or female gametophytes Pollen (air-borne) Allows for transport over large distances Ovules Also note: water, again, was not necessary any more. This is thanks to pollen grains Seeds have embryos of the sporophytes in it o Dessication A resistance to harsh environmental conditions Gymnosperms The seeds are exposed on sporophylls that form cones o Most gymosperms, as such, are called conifers Megasporangium (on a Megaspor Female Eggs megasporophyll) e gametophyte Microsporangium (on a Microspor Male Sperm microsporophyll) e gametophyte THIS IS HETEROSPORY Female Gymnosperm Anatomy Ovule o Made of three things: Diploid tissue -> megasporangium tissue Produces the megaspore Ultimately becomes the nutrients that is used as food Megaspore -> produced through mitosis Integument -> ultimately, the seed coat Male Gymnosperm Anatomy Three things: o Microsporangium tissue -> diploid tissue Produces haploid spores (aka, the MICROSPORES) o Microspores -> the male gametophyte Develops into Pollen Grains, which carries the actual male gametophyte o Pollen -> contains the male gametophyte within the tough pollen wall Essentially, this surrounds the microphyle Pollination The transfer of pollen to the part of the seed plant containing the ovules IF a pollen grain germinates and pollinates an ovule, it develops a pollen tube that grows through the megasporangium in order to come into direct contact with the megaspore Direct fertilization The pollen tube digests bit by bit in order to come into contact with the megaspore Embryo arises from the fertilization A sporophyte that will develop slightly because going dormant Can survive "on pause" here for thousands of years Pine tree o Is a sporophyte o Female cones are on the top of the tree, while the male parts are on the bottom Avoids self-fertilization o Four types Coniferophyta Firs, pines, larches, junipers, sequoias Cycadophyta Palm-like leave with large cones Gnetophyta Oddballs Like the funny looking C4/Cam plants on the deserts Gingkophyta Only Gingkos One male gametophyte per one sperm 2/13 Chapter 30: Angiosperms (Seed Plants) Angiosperm o "container" & "seed" o The most widespread and diverse of all plants Flowers and fruits are actually reproductive structures o Seeds are to prevent desiccation o The sporophyte stage is the most prominent; the gametophyte stage is usually microscopic o Phylum Anthrophyta ALL belong to this "anthos" is Greek for flower Flowers o Structure single-handedly specialized for sexual reproduction Many are pollinated by insects or animals, while some use wind=pollination Many types specifically will target particular pollinators based on their likings Anatomy Up to four types of modified leaves Sepals - encloses the flower; usually green Petals - brightly colored and for attracting pollinators Stamens - produces pollen Filament - has a sac (called an anther) that produces pollen) Carpels - produces ovules Three parts At the bottom is the ovary itself The stigma is sticky in order to keep/catch pollen The style connects the two Fruits o A matured ovary o Occasionally includes other flower parts Protect the seeds Aids in seed dispersal Fleshy or dry Ex: oranges/grapes or beans/grains, respectfully o Forms when an ovary wall thickens and matures o Various adaptations help with dispersal Can be carried by wind, water, or animals o Example fruits Universal structures Well, all have seeds Tomato, grapefruit, nectarine, hazelnut, milkweed There are some fruits that actually explode Some have 'wings' that can help them fall farther away Life cycle o The flower of the sporophyte is composed of both male and female structures That is, of course, with exceptions every now and then o Male gametophytes are within pollen grains produced by the microsporangia of anthers Each pollen grain has two sperm within it o The female gametophyte (embryo sac) develops within an ovule contained within an ovary at the base of a stigma When pollen lands on the stigma, a pollen tube extends down and into the embryo sac From here, the sperm connects to the egg from within the embryo sac It enters through a pore called the MICROPHYLE Double fertilization occurs This is unique to angiosperms The pollen tube discharges two sperm One fertilizes the egg The other combines with the two nuclei within the Central Cell which produces the Endosperm This is thus triploid (3n) tissue and it develops into the food supply for the embryo Within the seed, there is a root as well as the two very first leaves to emerge o These are called Cotyledons They supply food to build that first root as well as to build photosynthetic leaves o Most flowers have different tools to prevent self-pollination Aka, promotes cross-pollination Considered "the most adaptive towards living life on land"
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'