0:02 reproduction and fungi
0:04 the most common form of reproduction in
0:07 fungi is asexual reproduction
0:10 the parts you most commonly see such as
0:13 toadstools and puffballs are asexual
0:17 fruiting bodies full of spores
0:20 the molds that rot our food
0:23 also reproduce asexually
0:25 many fungi are made up of a mass of thin
0:28 threads called hyphae that together form
0:31 the structures that we can see
0:34 in asexual reproduction the fungal spores
0:35 spores
0:38 are produced by mitosis and they are
0:41 genetically identical to the parent
0:43 if you want to understand spores think
0:46 of seeds in plants
0:48 some fungi
0:50 also reproduce sexually when the
0:52 conditions are not good
0:55 for example when it's dry
0:58 too high fee from different fungi join
1:00 and the nuclei fuse
1:03 so the new hypha has two sets of chromosomes
1:04 chromosomes
1:07 so it goes from the haploid state hyphae
1:10 are haploid they have n chromosomes
1:13 and their nuclei fuse so now we have two
1:15 n chromosomes we are in the diploid state
1:16 state
1:18 it undergoes meiosis to make haploid spores
1:20 spores
1:23 each with only one set of chromosomes so
1:25 n chromosomes
1:27 so we had the high feet joining together
1:28 going from
1:31 n chromosomes to 2n chromosomes
1:35 then undergoing meiosis to produce
1:37 daughter cells or spores that have n
1:41 chromosomes so haploid again
1:44 the chromosomes of hyphae are different
1:46 from the original hyphae different from
1:49 the parent hyphae that fused together to
1:52 make the diploid that underwent meiosis
1:53 and this is the variation that we talked
1:56 about in sexual reproduction
1:58 some spores may produce fungi that are
2:00 better adapted to survive the adverse
2:03 conditions and this is why
2:05 sexual reproduction and fungi happens
2:08 when the conditions are unfavorable
2:11 in order to play the game of chance
2:14 to see if the fungus can produce
2:17 offspring that are better adapted to the
2:19 new environment to the new conditions of
2:21 its environment
2:22 otherwise if the conditions are
2:24 favorable and stable
2:26 the fungus will undergo asexual reproduction
2:33 we have spores
2:34 spores
2:36 being produced
2:38 by mitosis asexually as long as the
2:41 conditions are favorable
2:43 the spores become hyphy and then the
2:45 hyphae makes pores
2:47 by mitosis
2:49 here they are in the haploid state with
2:52 n chromosomes
2:54 the spores will germinate
2:57 to form a new fungus the new fungus has
3:00 hyphae each hypha which is the singular
3:02 of hyphae
3:05 can produce spores
3:07 through mitosis
3:09 now the second the conditions become unfavorable
3:12 unfavorable
3:15 then too hyphy will join together will
3:17 fuse to make a zygote
3:19 a diploid
3:21 hypha with two n chromosomes it will
3:23 undergo meiosis
3:25 to form
3:27 the haploid spores now what is the
3:28 difference between these pores produced
3:31 by sexual reproduction and the spores
3:33 produced by asexual reproduction
3:36 they are both haploid with n chromosomes
3:38 however the spores produced by asexual
3:41 reproduction have the exact same genes
3:44 as the parent they are identical
3:46 the spores produced by sexual
3:48 reproduction are different from each
3:49 other and from the parent there is
3:51 variation here
3:53 these spores will then germinate into a
