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Flashcards by jennabarnes12387, updated more than 1 year ago
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Created by jennabarnes12387
over 10 years ago
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| Question | Answer |
| where do we think the first plants originated from? | Charophycean, a group of green algae, over 500 million years ago |
| What do plants have in contrast to protists? | they are multicellular and they have cellulose in their cell walls |
| what 5 problems did plants have to solve when moving from an aquatic to a terrestrial environment? | how to transport the sperm to the egg, gather water and get it to all parts of the plant, conserve water as it is more limited in terrestrial environments, new supports to stay up without the support of surrounding water, all for gas exchange in a multicellular thickness |
| How were these problems solved? | alternation of generation life cycle, apical meristems whci hare localized regions in cell division, to acquire light and water, multicellular gametangia nad embryos to prevent embryos and gametes from drying out, and sporopollenin walled spores to resist drying and decay |
| earl plants didnt have roots. How do we think they got their nutrients? | by forming symbiotic relationships with fungi called mycorrhizae |
| what were the benefits of plants moving to a terrestrial environment? | more sunlight, carbon dioxide and nutrients, |
| what are the drawbacks of a terrestrial environment? | limited water meaning relationships were needed |
| what are non-vascular plants? give an example | they don't have xylem and phloem tissues for water distribution |
| Phylum Bryophyta includes what kind of plants? | mosses |
| mosses have to make relationships because they have limited absorptive tissues. what are these tissues called? | rhizoids |
| what is the haploid (n) or asexual generation is called what? | gametophyte generation |
| what is the diploid (2n) or sexual generation called? | sporophyte generation |
| which generation is longer; gametophyte or sporophyte? | the gametophyte phase is dominant meaning its longer |
| which generation is more complex; gametophyte or sporophyte? | the sporophyte generation is more complex and has stomata for the gas exchange in the thicker body |
| what are stomata? | tiny openings that control turgor pressure by releasing water vapor into the atmosphere and brings in carbon dioxide |
| moss protonema. this is the early stage of the development of the gametophyte. these tentical like projects grew from the spore that was produced during the sporphyte generation. soon buds will form into leafy gametophyte and into a fully grown mass plant | |
| This is the antheridial head. the antheridia shown in the picture are oval shaped structures with non reproductive cells around it. flagellated sperm are produced inside. these antheridia are separated by non reproductive filaments of cells called paraphyes | |
| this is the archeological head. found in female gametophytes. its a cluster of archegonium which are vase shaped structure where egg cells are produced. water will then bring sperm from antheridial head a diploid zygote will be made and then continue to grow while attached to the gametophyte | |
| the sporphyte has a foot that stays anchored in the female gametophyte. a stalk called a seta grows up and a capsule grows at the top. | |
| as the sporophyte grows up from the female gametophyte a layer of haploid tissue from the gametophyte stays on the capsule called the calypatra and is eventually shed. inside the capsule is the sporangium or sporagenous tissue where diploid mother spore cells are formed. through meiosis they become spores . at the tip of the capsule is a cap like structure called the operculum. at the right time the operculum pops off and the spores are released. the spores can then develop asexually into gametophytes. | |
| how is the life cycle of bryophytes and other vascular plants different then that of non vascular plants like moss? | multicellular gametophytes and sporphytes that look different. Multicellular reproductive like the antheridia with sterile protective cells. embryos that develop inside the gametophyte and then stay attached as they grow |
| phylum pterophyta include what type of plants? | ferns |
| are ferns vascular nor non-vascular? why? | yes because they have conductive tissues called xylem and phloem |
| the visible part of the plant is called the fronds. they are attached to an underground stem called the rhizome. this is the diploid sporophyte stage. the red dots under the leaf are called sori or a cluster called sporangia. the leaves that have sporangia are called sporophylls | |
| sori are often covered by a shelf like structure called the indusium that protects them until they are mature. each sporangia has specialized cells with uneven cell walls in a group called the annulus. as the sporangium matures it dries out and the annalus bends. eventually the tension of the water in the annulus is greater then the cohesion. the water becomes vapour the the cells go back to their original shape. the shape change is so quick it literally whips the spores away a great distance | |
| under the upper epidermis are tightly packed cells called the palisade layer. below this are loosely arranged cells with intercellular space called the spongy mesophyll layer. below this you will see veins of xylem and phloem cells for vascular transport. xylem tissue transport water and minerals and supports terrestrial plants. phloem tissue moves food around the plant and as a conducting agent | |
| the small black dots on or hear the rhizoids of the prothallus are called the antheridia. as with moss, sperm is produced here and must be transported by water. the vase like strucutres near the notch of the prothallium are the achegonia and are where the eggs are produced. although the antheridia and the achegonia are close together they develop at different times so cross fertilization can occur. | |
| when the egg is the archegonia is fertilized the sporophyte grows from it until it is independent and the gametophyte then degenerates | |
| phylum lycophyta includes what type plants? | lycopods such as cone bearing pine trees that produce two types of spores and two types of sporangia |
| this is an advanced type of condition in cones where two different spores and two different sporangium. The larger sporangium usually near the base of the cone is called a megasporangium and it produces megaspores. only a small number of these cells are produced and these megaspores will eventually mature into megagametophytes meaning female gametophytes. The smaller sporangiums are the microsporangiums that produced microspores. the spores are very small and large in number. they will develop through meiosis into microgametophytes meaning male gametophytes. | |
| what are the names of the male and female gametophytes of phylum lychophyta? | the male gametophyte looks like a bumpy pokey ball and is called an antheridium. it will release flagellated sperm when it reaches a female gametophyte. the female gametophyte grows into an archegonium containing eggs until it is fertilized by the antheridium's sperm |
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