Gymnosperms (Cycads, Ginkgo , and conifers) identify and state the differences o
ID: 68577 • Letter: G
Question
Gymnosperms (Cycads, Ginkgo, and conifers)
identify and state the differences of: cycad, Ginkgo, or conifer
- Know the definition and function of these terms AND whether it is haploid (N) or diploid (2N) : columnar trunk, bulbous trunk, male strobilus/i, female strobilus/i, pollen sacs (also called microsporangium/ia), pollen grains, megasporangium/ia, ovule, seed, stem, megasporophyll, microsporophyll, long shoots, short shoots, female cone, scale, winged seed
- Know the definition and function of: integument, megasporangium/nucellus, archegonium with egg, micropyle, megaspore wall, pollen chamber, female gametophyte
- Compare and contrast spore plants and seed plants (especially in regards to reproductive structures)
- Compare and contrasiont a gymnosperm (conifer) and an angiosperm (especially in regards to reproductive structures and pollination)
Explanation / Answer
Gymnosperms (Cycads, Ginkgo, and conifers)
identify and state the differences of: cycad, Ginkgo, or conifer
The Gymnosperm include the Cycads, Gnetales and the Ginkgo as well as the Conifers as true trees with xylem & phloem wood growth patterns. They have reinforced fibers to hold themselves up under the pressure of their weight and they have xylem & phloem vesicles. However only conifers have 'compression wood' at branch joints. The reinforcing wood forms under the branch to resist the branch bending down under its own weight. This allows conifers to grow long branches angled outward from the main trunk. The long horizontal branches gather more sunlight by covering more area while allowing light into lower branches by spacing the branches around the trunk in a spiral.
The name gymno, meaning naked or bare, refers to the cone-like seed bearing structure they use to reproduce. The female cone has scales, spiraling around a central axis, that each shelter an integument covered ovule but have no closed ovary as in one of the Angiosperm (flowering plants).
Conifers are the major family of Gymnosperm (nonflowering plants). Conifers are the gymnosperm with needle-like or scaled leaves that grow the most well known type of male and female cones as reproductive organs. However it is the Cycads that are the ancestral or parent plant family to the conifers. Cycads are strictly tropical while conifers have adapted to all climates from the tropical to the high latitude taiga.
Definition and function of: integument, megasporangium/nucellus, archegonium with egg, micropyle, megaspore wall, pollen chamber, female gametophyte
Integument: Maternal tissue that protects the ovule; the integument forms the seed coat.
Just like any other organ system in your body, the integumentary system does accomplish certain functions of vital importance. All the smaller and larger parts, including skin, hair, nails, glands and nerves, have their own particular jobs, thus ensuring the survival and the maintenance of perfect health of the individual. The tasks assigned to this system include protection, regulation of the body temperature, metabolic assistance, blood reservoir, cutaneous sensation, excretion and so on.
megasporangium/nucellus: An ovule is a saclike structure that produces the megaspores and is enclosed by layers of cells. This megasporangium is called the nucellus in angiosperms. After initiation of the carpel wall, one or two integuments arise near the base of the ovule primordium, grow in a rimlike fashion, and enclose the nucellus, leaving only a small opening called the micropyle at the top.
archegonium with egg: Archegonium, the female reproductive organ in ferns andmosses. An archegonium also occurs in some gymnosperms,e.g., cycads and conifers. A flask-shaped structure, it consists of a neck, with one or more layers of cells, and a swollen base—the venter—which contains the egg. Neck-canal cells, located above the egg, disappear as the archegonium matures, thus producing a passage for entry of the sperm. The sperm are produced in the corresponding male reproductive organ, the antheridiu.
micropyle: The micropyle covers the upper surface of the egg andis not depressed.The function of the stalk and of the micropyle duringthe development of the ovum is undoubtedly a nutritiveone.
megaspore wall: Gymnosperms and angiosperms form two kinds of spores: microspores, which give rise to male gametophytes, and megaspores, which produce female gametophytes.
Two kinds of gametophytes develop from the two kinds of spores produced by the sporophyte in different sporangia; the larger spore (megaspore) gives rise to the female gametophyte, the smaller spore (microspore) to the male. This condition is referred to as heterospory.
pollen chamber: A pollen tube is part of the male gametophyte of seed plants. It acts as a conduit to transport the male gamete cells from the pollen grain, either from the stigma (inflowering plants) to the ovules at the base of the pistil, or directly through ovule tissue in some gymnosperms. In maize, this single cell can grow longer than 12 inches to traverse the length of the pistil.
female gametophyte: The female gametophyte is also referred to as the embryo sac or megagametophyte. It develops in the ovule, which is found within the carpel's ovary. The most common female gametophyte form, consists of seven cells and four different cell types: three antipodal cells, two synergid cells, one egg cell, and one central cell.
Compare and contrast spore plants and seed plants (especially in regards to reproductive structures)
Seeds vs Spores
There are a lot of differences between the two, and understanding this can help you effectively distinguish a seed from a spore.
First off, a seed is much larger than a spore. Seeds can be seen and touched easily, while you’ll need a microscope in order to see spores. You definitely can’t scrutinize spores with your eyesight alone. You need a magnifying apparatus, such as a microscope, in order to check out spores. Aside from their tiny size, spores come in two types: heterosporous and homosporous. The former is further differentiated into a small male spore and a big female spore, while the latter comes in uniform sizes. Seeds also come in two types: a diploid, which has two, paired chromosome sets, or a haploid, which has only one paired chromosome set.
Second, a seed is more complex than a spore. Seeds are considered more advanced than spores, not only because of their size, but because of how they sustain plant life. In fact, the inner workings of a seed reveal a full-fledged multicellular environment capable of nurturing the plant and preparing it for the outside world. It has facilities for nourishment and defense, augmenting the plant’s survival chances. On the other hand, a spore is unicellular and simpler in structure but, like the seed, it is also able to survive in the outside world.
Third, seeds and spores differ when it comes to their location. Seeds can be found either in flowers or the fruits of flowering plants, while spores are located underneath the leaf area of fungi, ferns, and moss plants. Once they are released into the outside world, seeds can sprout just about anywhere. They’re not choosy about where they’ll germinate. On the other hand, a spore requires a wet environment, such as a marsh or a swamp, in order to germinate.
Fourth, seeds and spores may be transported to the outside world by different means. Seeds can be transported by animals who eat the fruit of flowering plants and either disseminate or disgorge the seeds within. Seeds can also simply fall off the plant and roll to the ground where they will germinate once they have been sufficiently nourished with enough water and sunlight. On the other hand, spores simply fall off of leaves and float slowly to the ground or are wafted upwards and spread further by air currents.
Compare and contrasiont a gymnosperm (conifer) and an angiosperm (especially in regards to reproductive structures and pollination)
Angiosperms Gymnosperms
Definition Seed-producing flowering plants whose seeds are enclosed within an ovary. Seed-producing non-flowering plants whose seeds are unenclosed or “naked.” Seeds Enclosed inside an ovary, usually in a fruit. Bare, not enclosed; found on scales, leaves or as cones. Life Cycle Seasonal (die during autumn/fall). Evergreen Tissue Triploid (endosperm produced during triple fusion) Haploid (endosperm produced before fertilization) Reproductive system Present in flowers; can be unisexual or bisexual Cones; unisexual Leaves Flat scalelike , needle-like Cotyledons Present; single (monocots) or in a pair (dicots) Absent Wood Hardwood Softwood Periniality Non-perinnial Perinnial Kingdom Plantae Plantae Domain Eukarya Eukarya Reproduction Mostly rely on animals. Mostly rely on wind. Uses Medications , food, clothing, etc... Paper, Lumber , etc...Related Questions
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