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Plant Reproduction Angiosperms, mosses, and ferns.

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Presentation on theme: "Plant Reproduction Angiosperms, mosses, and ferns."— Presentation transcript:

1 Plant Reproduction Angiosperms, mosses, and ferns

2 Plant reproduction  Plants use both asexual (one) and sexual (two) reproduction to pass their genes onto the next generation.

3 Plant reproduction  Plants use both asexual (one) and sexual (two) reproduction to pass their genes onto the next generation.  Lower plants – sexual repro. produces spores from meiosis

4 Plant reproduction  Plants use both asexual (one) and sexual (two) reproduction to pass their genes onto the next generation.  Lower plants – sexual repro. produces spores from meiosis  Higher plants – gametes fuse to form a zygote which develops into an embryo inside a seed.

5 Plant reproduction  Plants use both asexual (one) and sexual (two) reproduction to pass their genes onto the next generation.  Lower plants – sexual repro. produces spores from meiosis  Higher plants – gametes fuse to form a zygote which develops into an embryo inside a seed.  http://www.youtube.com/watch?v=FsBQQD g5GIw http://www.youtube.com/watch?v=FsBQQD g5GIw

6 Plant reproduction  Plants use both asexual (one) and sexual (two) reproduction to pass their genes onto the next generation.  Lower plants – sexual repro. produces spores from meiosis  Higher plants – gametes fuse to form a zygote which develops into an embryo inside a seed.  http://www.youtube.com/watch?v=FsBQQD g5GIw http://www.youtube.com/watch?v=FsBQQD g5GIw  http://www.youtube.com/watch?v=drcnTg7Z Coc http://www.youtube.com/watch?v=drcnTg7Z Coc

7 Plant reproduction  Seeds are dispersed by

8 Plant reproduction  Seeds are dispersed by  http://www.youtube.com/watch?v=zbQ1 jWl3AOM http://www.youtube.com/watch?v=zbQ1 jWl3AOM

9 Plant reproduction  Seeds are dispersed by birds and wind etc to a range of habitats.

10 Plant reproduction  Seeds are dispersed by birds and wind etc to a range of habitats.  Some habitats may be suitable for the germination of the seed, but some may not – this results in large losses of seeds and genes from those parent plants.

11 Plant reproduction  Seeds are dispersed by birds and wind etc to a range of habitats.  Some habitats may be suitable for the germination of the seed, but some may not – this results in large losses of seeds and genes from those parent plants.  Some seeds will tolerate the habitat because it is similar to the one their parents were in.

12 Plant reproduction  Asexual plants produce offspring by mitotic cell division – all offspring are genetically identical to their parent.

13 Plant reproduction  Asexual plants produce offspring by mitotic cell division – all offspring are genetically identical to their parent.  Eg  Strawberries produce horizontal stems called runners.

14 Plant reproduction  Asexual plants produce offspring by mitotic cell division – all offspring are genetically identical to their parent.  Eg  Strawberries produce horizontal stems called runners.  Eg  daffodils and onions produce bulbs underground.

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16 Plant reproduction  Conditions are usually ideal for the new plants growing through asexual reproduction.

17 Plant reproduction  Conditions are usually ideal for the new plants growing through asexual reproduction.  This can cause problems because of the dense population of the plant. Eg  old man’s beard.

18 Plant reproduction  Conditions are usually ideal for the new plants growing through asexual reproduction.  This can cause problems because of the dense population of the plant. Eg  old man’s beard.  However, colonising new habitats is difficult for asexual reproducers because there is no dispersal mechanism.

19 Alternation of generations  Where a diploid (double set of chromosomes) asexual generation is followed by a haploid (one set of chromosomes) sexual generation.

20 Alternation of generations  Where a diploid (double set of chromosomes) asexual generation is followed by a haploid (one set of chromosomes) sexual generation.  Gametes from gametophytes fuse to form a zygote, which grows into a sporophyte.

21 Alternation of generations  Where a diploid (double set of chromosomes) asexual generation is followed by a haploid (one set of chromosomes) sexual generation.  Gametes from gametophytes fuse to form a zygote, which grows into a sporophyte.  Sporophytes produce haploid spores from meiosis which grow into gametophytes.

22 Alternation of generations  Sporophytes contain double the genetic info as gametophytes and also produce spores which are genetically unique, so the trend in plant evolution has to be; increase the size and development of the sporophyte at the gametophyte’s expense.

23 Mosses  Spores produced by the sporophyte are resistant to drying out, and are blown until they settle and germinate into gametophytes.

24 Mosses  Spores produced by the sporophyte are resistant to drying out, and are blown until they settle and germinate into gametophytes.  Gametophyte is the dominant generation, being larger and with a longer lifespan than that of the sporophyte.  http://www.youtube.com/watch?v=jcWYAn mm-QE http://www.youtube.com/watch?v=jcWYAn mm-QE

25 Mosses  Spores produced by the sporophyte are resistant to drying out, and are blown until they settle and germinate into gametophytes.  Gametophyte is the dominant generation, being larger and with a longer lifespan than that of the sporophyte.  Gametophytes produce sperm from a male gametangium and eggs from the female gametangium.

26 Mosses  Spores produced by the sporophyte are resistant to drying out, and are blown until they settle and germinate into gametophytes.  Gametophyte is the dominant generation, being larger and with a longer lifespan than that of the sporophyte.  Gametophytes produce sperm from a male gametangium and eggs from the female gametangium.  Reproduction requires water, because sperm must swim to an egg for fertilisation to occur.

27 Ferns  The sporophyte is the dominant generation.

28 Ferns  The sporophyte is the dominant generation.  Fern spores are produced on the underside of fronds and germinate in damp conditions into very small heart- shaped gametophytes.

29 Ferns  The sporophyte is the dominant generation.  Fern spores are produced on the underside of fronds and germinate in damp conditions into very small heart- shaped gametophytes.  Gametophytes survive for just a few weeks. Sperm need water to swim to the egg of a nearby female.

30 Ferns  The sporophyte is the dominant generation.  Fern spores are produced on the underside of fronds and germinate in damp conditions into very small heart-shaped gametophytes.  Gametophytes survive for just a few weeks. Sperm need water to swim to the egg of a nearby female.  The sporophyte formed after fertilisation draws nourishment from the gametophyte only until the sporophyte begins to photosynthesis.

31 Ferns  The sporophyte is the dominant generation.  Fern spores are produced on the underside of fronds and germinate in damp conditions into very small heart-shaped gametophytes.  Gametophytes survive for just a few weeks. Sperm need water to swim to the egg of a nearby female.  The sporophyte formed after fertilisation draws nourishment from the gametophyte only until the sporophyte begins to photosynthesis.  The fern sporophyte is well adapted to the land environment. Ferns – the ponga and silver fern have evolved to colonise a number of habitats even though they still require water for reproduction.

32 Ferns  http://www.youtube.com/watch?v=eZ40L DWt678 http://www.youtube.com/watch?v=eZ40L DWt678

33 Questions 1. A plant reproduced asexually for two generations. What must be assumed about the chromosome number of the second generation?


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