[Music] welcome life sciences to another new exciting life science lesson we are on the path of plant biodiversity now i know that most of you when you hear the word plants you start to roll your eyes and it's not always your favorite part of life science but i must tell you it's the part that you can see the most it's around you all the time right and it's you can actually do a lot with it you can go and touch it you can feel it you can see it so plants are really really awesome so what are we looking at so just a quick recap from our last lesson what we would have looked at we started looking at this whole concept of the plant kingdom right so plants are multicellular or organisms they have chlorophyll they can photosynthesize right they have got roots stems and leaves and in our last lesson we looked at the evolution of plants we looked at the moss right bryophytes we looked at the fern terridophytes we looked at the pine cone gymnosperms and then we looked at all right the highest order of all our plants our angiosperms our flowering plants now today's lesson we're going to look at a very important concept on how plants reproduce and when we looked at the evolution of plants right we saw this whole concept about how water played a big role in reproduction in the beginning and how it started to lose its significance towards the end when we got to our gymnosperms and our angiosperms now the concept that i want you to think of we're looking at how plants reproduce and we're going to look at two ways right that the plants can reproduce it's either asexual reproduction or by means of sexual reproduction now i want to pose this question to you when we think of plants i often think you guys have a concept of flowers maybe plants all right in your garden grass or whatever but what i actually want you to think of and this is the most important thing about plants is plants are food so when we're looking at the concepts that we're going to write teas are today the asexual and the sexual reproduction i kind of need you to put on a farmer's hat right what do i mean by that is we're not thinking like what kind of flower i want am i going to make my garden pretty i'm thinking along the lines of i have got to make food all right i have got to produce food i've got to make crops i've got to feed our country because that is what plants actually are and the concept that we're looking at here very simply is am i looking for something that's predictable do i want the same thing over and over again because i know what i'm going to produce or do i want the unpredictable right do i want something new because with that something new right something new that's really good in my crops could come about so that's the process i want you to think about today when we're looking at asexual versus sexual reproduction we're looking more and a lot lines of predictability versus something new that could bring something really good that we haven't seen before right so when we're looking at asexual and sexual reproduction right we're going to look at the concept and then for each of them you need to be able to all right decide what are the advantages of this type of reproduction so as a farmer maybe what would the advantages be to me or what would the disadvantage why would i not use this process and exactly the same on the other side for sexual reproduction what are the advantages of sexual reproduction versus the disadvantages knowing all right the pros and the cons for each of those now there's a few new words that might come into being here as i said you it's the terminology we're going to use you new words you need to understand what they mean and you need to know how we use them in this concept of the plant biodiversity okay so we're going to start off now and we're going to look at as i said to you there are two ways in which plants can reproduce now please understand that some plants can use both methods it's not necessarily a plant can just use asexual or just use sexual some plants are able to use both their methods okay so when we're looking at that that's the concept don't think that it's just going to be the one so the first thing we need to look at is what is reproduction now the concept of reproduction is to make offspring what is offspring its children if i could use it obviously not in the plant since because that's where we're looking at so a plant making another plant all right a new plant giving rise to something new carrying on that species carrying on the traits of that plant that is what we're talking about when we look at reproduction making more of you making more of the plant so we're looking at plants so plant making right being able to give rise to another plant and the two ways in which it can do that is asexual or sexual and we're going to look into those concepts right so now we're going to look at the concept of asexual reproduction and here there are quite a few terms that we're going to use that might be new i'm going to highlight them i'm going to underline them right and i'm going to explain the concept to you right so let's start off kicking off with what exactly is going to be all right what exactly is asexual reproduction now guys we don't tend to use asexual reproduction a lot we use the word vegetative propagation right and propagation just means to make something new so when we're looking at asexual reproduction these are the most important things number one there is only one parents now the lesson that we are going to look at later in the series involves the whole structure of a flower and when we get to a flower i'm going to quickly draw and if we look at a flower over here what a flower has is male and female structures we'll look at that just now this when it comes to asexual reproduction right that is not going to be the case one parent we're going to have one plant is able to give rise right to many so you have this concept where you take away this concept of male and female which leads us to our second point when we have male and female male and female give rise to a gamete and what the word gamete means is a sex cell right so what it means is is that a male will give rise to a male sex cell and a female will give rise to a female sex cell plants pollen is the male sex cell in the plant the ovule is going to be the female but you're going to get a much greater idea of that in our next lesson when we look specifically at the flower so what happens here is when we look at this process this is the key word it is mitosis now you guys have probably done mitosis before and mitosis means to make an identical copy right so now i'm going to let you to start thinking this word predictable all right if i am going to use or undergo asexual reproduction the process is by mitosis and that means to make an identical copy so if i know what i've got all the offspring are going to be the same which leads us to our lance last plant when something is the same we use the word a clone right cloning is to make something identical so when we're looking at the concepts of asexual reproduction we it's about predictability it's making clones so if i have got this plant say for example right with a really big say for example potato and it's a really big potato i can take this potato and i'm going to keep making offspring because i know it's going to be a big potato so it's predictable i know what i'm going to get all right that is where the concept is of asexual reproduction this process of mitosis right of cloning i know what i'm going to get now guys you need to look at a few examples of how plants can use it right we still first thing we're going to look at is stems now the two examples over here i've given you the first one i've said it's an onion right but if i have a look at this one over here this is garlic right now both of them if you have a look over here there's a little bud now what does a bud mean the bud makes new features you don't see anything about a male and you don't see anything about a female and all the bud does he has my bud it divides by mitosis layer onion layer onion layer onion look at the bottom there's a root so it's a root what is my stem doing there's a bud growing growing growing right and what are onions what a garlic they are food all right remember this concept of food so they don't need a male they don't need a female in this regard right what we call them guys this is important it's a bulb that's the important word they are bulbs they are underneath the ground and they can make new plants all right just by that little bud okay our next example is a runner or a stolon now the best example that you probably write might be able to get to quite quickly is grass i don't know if you've ever if i pull out grass so i take a piece of grass and i pull it and not one doesn't it doesn't come up just as one as i pull it a whole long thread right so i pull up grass and it just goes long long long long long okay that is what a runner or a stolen is so have a look over here look see this is the plant and what it does is it produces and basically it's a stem above the ground from the roots and guess when biomitosis and what does it start to develop it starts to develop new roots and it produces a new plants can you see over here no male or no female all right involved in this and grass is an example another one is strawberries right strawberries the lovely yummy strawberry fruit that's also an example of it okay the next one believe it or not guys is bananas now i want you to have a look over here this is called a rhizome and a rhizome is an underground stem and you would have heard this word when we did the fern the fern had a alright a rhizome and what it does here i want to look at this diagram just by mitosis a little all right part of the stem starts to grow and what do i have right next to it a beautiful new banana tree all right banana is an example of also of how some plants can use right to reproduce a sexually ah potatoes how many of you guys all right have got those potatoes that you leave in like maybe a cabinet and the next thing you know you go to your potatoes and look what they've got growing from them they've got these little like like things growing those guys are our new plants they are called little potato eyes all right and believe it or not and i've actually done it you take these you cut the potato and you put it in the ground and guess what's going to happen new potato plants this is what we call a tuber right it's still a stem and it is a tuber right okay guys and these little eyes are going to become the new potato so by the process of mitosis we're going to just produce new potatoes right these are cuttings now have a look over here i've done this lots of times before with this particular plant have a look at this diagram all i did was i cut the stem and i put it in water and guess what happened the stem grew roots and as soon as the roots are visible i go in i plant in the ground but actually i actually cut out the step totally i actually took the leaf right and i put it directly in the soil and in the soil it started to grow roots and i grew a beautiful geranium a cutting yes i know it's not natural but it is a way right in which we can reproduce all guys now the next one are root tubers okay now where is potatoes with stems sweet potatoes right much a little bit more healthier than our potatoes sweet potatoes again food right are roots they're root tubers and again they're going to produce these little tubers asexually by mitosis and as i said to you again we're going to have the food here is an example all right sometimes a sucker right comes out a sucker comes out and a new plant grows this is called the pen during and it's a around a plant almost like a bit of a thorn tree right that is endemic to our country so over here the pandering is example of a tree that can actually right develop via a sucker so that we've got bulbs we've got tubers we've got stolons we've got suckers that grow out of the root right the least common of them all right is leaves and you can some this is called the cape primrose right and what we can do not so much for food but maybe looking pretty we can cut the leaf and we just cut it over here and we put it into the soil and you see what happens new little plants are starting to develop the roots are going to grow and ultimately we're going to get the new plants all of these ways done asexually so when we're looking at asexual reproduction predictability right we know what we're going to get okay guys we're going to have a quick break i will see you in just a bit [Music] welcome back life sciences i hope you had a little bit of a small break and maybe you could have checked out the plants around you right see if you could see any of the characteristics or maybe you went to your potatoes if you had them then to see if they were growing ice right now as i said to you one of the concepts we must look at is what are the advantages all right and disadvantages of asexual reproduction so let's have a look at the different points right guys we're looking at first remember you need to have your farmer's hat on if i could use that or you're a crop grower we're looking at the advantages why would it be right an advantage to grow my crops asexually now when we look at it the section that we're going to look at right after this we're going to look at the concept of a flower right now you need to look at this whole concept right as energy and what do i mean by that is this the advantages of asexual reproduction they don't have to make a flower making it give energy all right now we need another thing what i don't have all right is pollinators if i don't have a flower what do i not need i don't need the bees i don't need butterflies i don't need birds i don't need i'm taking the middle man if i was to use that out of the equation so it's actually for the plants it saves them a lot of energy right having not no flour not having to make the pollen right because remember what we said pollen was the male part and the flower is the sexual reproductive organ so we're taking them out the equation right but what does that mean for us it means quick right guys it's quick right i don't have to rely on all of those things i don't have to find a partner right i don't have to rely on the pollinators of taking it from the male to the female the one parent can do it it's quick right it's cheap it's simpler why do you think grass is grass why do we use it for our lawns very simply we buy them on the street corner and grass is actually quite cheap we lay them down right and what happens all those little runners go and soon our garden all right is full of grass and i have the battle of the weeds as well but it's a quick and it's a simple and it's a cheap method okay now we're getting into a concept that you're going to look at much later when we look when you do more of dna etc in when you do grade 12 work etc but this is called it's genetically identical now what that means is remember we said we made a clone and a clone means i know what i'm getting year after year after year so remember it's all about this predictability now when things are genetically right identical this is good when conditions are stable what i'm talking about now is the environment is stable if so for example we got global warming coming or something changes the environment changes okay that is an unstable environment and that we're going to look at it's a disadvantage because it's got the same genes it might not adapt but if it's the same environment year after year after year i'm going to produce the same thing the same predictability if that is what i want remember what what do i what so what happens here then all right is that if a change does occur and this word here is a favorable mutation if maybe by some charge during mitosis something goes wrong but it's a good something goes wrong that mutation all right is going to be passed on very quickly because why process of mitosis it's going to start making identical copies with that really good trait but that is going to lead us right to and when we look at our disadvantages we're going to look at something else guys now as well the concept asexual reproduction does not give rise to a seed and seeds can lie dormant or they might need ideal conditions or they might grow in seasons and this means okay that if we don't have any seeds we can grow propagate means to grow the whole year around do you see it these are called hydroponics or tunnels and a lot of our food a lot of our fruits you guys are quite young my age when i was growing up we only had certain fruit in certain seasons because that is when they grew but now with asexual reproduction without that seed you actually can see and putting them in tunnels taking a bit of the environment away the seasons away you can actually grow certain things the whole year right seasonal so you're going to make money on those things the whole year you have strawberries usually the whole year you might even have oranges etc the whole year when right when i was growing up we only had them during the winter now if we have a look at the disadvantages the disadvantages basically go about this no genetic variation because it's the same thing same thing same thing if the environment changes they won't have the genes to be able to adapt it's one of the things that we look at when you're going to look at evolution evolution relies on this concept of mutation of change but mitosis cloning there is no change it's the same thing right so the problem is if you're going to have that and if the environment does change the plants might not be able to adapt and they could die out okay so that's exactly what will happen on the same line again if there's a strong gene they'll pass it on unfortunately if there is a weak gene if the plant sometimes you'll see one of the things is brown specks on the leaves that's not a good thing for the leaves that can be passed on so yes there are more advantages than disadvantages but in the long run what are you looking for okay let's have now look at the concept of sexual reproduction right and if we break down the word right when we talk about sex what are we talking about quite simply all right is there is usually two individuals involved so you need two partners all right two parents and this when we get to plants right involves gametes so we're going to have a male as we said is a pollen grain and we're going to have an ovule which is the female egg right be very careful that you say ovule because sometimes when you use another word for humans we use ovim and they're different things guys this is where we do not have predictability when you've got a male and when you've got a female you have no idea when you combine the two what you are going to get it is a surprise and because they are different all right what could happen is that surprise could hold something really good and new or maybe not so much now i want to show you you're going to look at the flower later but the whole concept of sexual reproduction is this this is the male and it's going to produce pollen it's the anther this is the female and this is the oval all right and what happens during reproduction is the male lands over here right he moves all the way and fertilization occurs so it's a whole it's a big process but the end result the end result of sexual reproduction is this concept of a seed and what information what genetic information is in that seed that comes from the male and what comes from the female okay so when it comes to sexual reproduction we don't know what we're going to get what's in the mail what's genetic material is pollen what is in the female and when those two fertilize what is going to come out in the seed what is the plant what is there something new is there not something new is there a trait maybe that makes it more resilient is it a good trait is it maybe resistant to insects or insect doesn't come so that's what we look at when we look at sexual reproduction right so what are our advantages now guys the advantages are mostly about this concept of genetic variation when we have genetic variation we can get something new and what does that mean very simply maybe the plant is resistant to a disease okay it brings in something new or when the environments are changed because it's got something new it stands a really good chance to survive in these different right situations also when we're looking at alright bringing in something new maybe the plant did have a harmful mutation but as soon as you bring in a male and a female you you you're not reliant on just the one it's quite possible that that harmful mutation we can eradicate we don't pass it on and it's gone whereas in mitosis we definitely had sexual i mean asexual reproduction we're definitely going to pass that on now guys the end result of sexual reproduction is a seed right and a seed has got a lot of advantages number one it can lie dormant right so it's got a seed coat it's got a protective covering and it can actually not do anything until it's really necessary sometimes hundreds thousands of years believe it or not but what can we do with the seed if you notice in um in asexual reproduction the potatoes it must produce a new plant right by it when it comes to sexual reproduction we've got this concept of a seed have a look here here are birds going to eat a fruit and the seed is in here the bird's going gonna fly away and that seed's gonna be dispersed a long distance have a look at this dandelion over here this is the seed guys this is a seed and what's gonna take it the wind is gonna take it and it's going to blow it a long distance away so when it comes to sexual reproduction the offspring can actually go really really far away from the parents where there might be more space there might be right more water more sunlight maybe not so crowded the conditions are ideal for that plant then to grow okay so what would be the disadvantages okay so what would be the things the the cons now as i said to you the plants when it comes to producing sexually they have to produce a flower and with that flower they're going to produce pollen and it needs a lot of energy all right it's slower it's time consuming you need pollinators so you can't use insect spray because then you're going to kill the insects along with the things that you really need okay and yes we could pass on unfavorable genes but as i said to you when you're looking at the concepts what do you want do you want something predictable or do you want something new it all depends on what we're looking at and very often when we're looking at food security being able farmers to feed our country lots of times maybe asexual reproduction might benefit because we know what we're going to get but playing around with sexual reproduction right getting to see the genes might be able to get something new that could be to the farmer's benefits okay guys we're going to have a quick break and we'll be right back just in a bit [Music] welcome back life sciences we are looking at the ace how plants are able to re reproduce make more copies of themselves in two different kinds of way asexual reproduction where we have a more predictable outcome and sexual reproduction we we don't right we have these new combinations now we're going to have a look at a few questions on this section i'm going to be honest with you it's very difficult the questions on this section usually link right to maybe sections that we looked at before on plant biodiversity when we looked at the fern angiosperms gymnosperms etc and the section we're going to look at after this is on flowers so very often when it comes to this all right to this reproduction of sexual and asexual right it's linked to a lot of the concepts that we're looking at right in plant reproduction but i've put together two they're very similar in nature but they just give you an idea of what kind of concepts to look for as i said we could maybe add things when we've done all the sections together okay the first question is a little bit of a reading piece and i don't know if you've ever heard of them right we're talking about varta blah mckees um i know it's an afrikaans term but the the word is either flakos or it's called in english it's called the pond weed all right and i know they don't look like flowers but that is what they look like right these are actually flowers i put a picture there just so that you can have it in your mind okay let's read for it they're flowers all right so if we look at the word flowers i want you to start thinking about sexual reproduction have been used as a food source for many years so we can eat them the most common way in which vitabol mickey flowers are prepared is as a traditional cape malay dish a lamb or mutton stew called vatable mickey bready all right the vatable mickeys are used as a vegetable in this dish so we're just giving you idea that we can actually eat the flowers now we're going to give you a little bit of more information plants grow in shallow dams so guys water water right that is a concept you need to all right think about because it could come up in some of the questions you'll see at the bottom here that shows you where they grow right and how they are harvested optimal growth take place in the water in temperatures of 14 degrees okay that is quite cold the seeds here we go are collected again a reference to sexual reproduction and lift in the water during august to develop roots okay so that is they live in the water the seeds are going to develop roots and a new plant is going to be involved this small now have a look the small bulbs right what do we know about a bulb a bulb is a means of asexual reproduction right so what happens is the seeds actually form bulbs they then take the bulbs out and then they plant those valves individually in dams right so what happens is asexual reproduction the older bulbs with more than one eyelet there we go those eyes remember like the potatoes are cut in half for higher production as each produces a new plant so here the eyelet and we cut in half no mention about male or female again it's telling us about asexual reproduction right our first question is nice and easy which part of the vitablomichi is eaten by humans now if we go back right if we have a look over here it said the flowers have been used as a food source and it gave you quite a few ways in which it could right so which part of the plant nice and easy part there it is the flowers okay now the leading question which two modes of reproduction are used by the vitabolomaki so we know that the two are asexual that's the one okay and sexual now that's we've got a mark there for that now it says to you over here list two reasons and that means how were you able to come up with the answer that it was sexual asexual and you must use the passage all right for how you got your supporting answer and it says here list two reasons so let's start off with the asexual now if i go back right to my asexual where did i make my first connotation here right they spoke about the small bulbs so i'm going to go back to my question and i notice bulbs the plant produces bulbs and what do these bulbs do right let's carry on going back what did they do okay they grew okay the bulbs with more than one eyelet so as the bulbs develop what did we do we cut the bulbs in half we cut them in half and we planted them and new plants right were formed so there we go that gave us the idea that this asexual reproduction now we're looking for the concepts now let's have a look at our question our a little information about these bulbs okay guys so we know that bulbs are a way of asexual reproduction and there's that word eyelets again we had the same when we had our potatoes right so when we look at our bulbs what did we do right we first of all the small bulbs were taken out and then they planted them into dams the older bulbs were cut in half all right so what did we do we cut the bulbs in half and we planted them nothing to do with seeds we cut them and what did they give rise to we planted them and they gave rise to a new plant no mention of seeds or flowers etc that was your key the word bulbs so if you don't know what the bulb is responsible for asexual reproduction you might have missed that okay now let's look at where it tells us sexual reproduction occurs and there are two places if we go back right i want to go back one more first of all a flower they eat them yes but we know that reproduction occurs sexually because a flower is produced all right so the first thing we're going to look at and just in case you might have missed this have a look here i'm going to go back there's a diagram of a flower and that tells us right of that this reproduction is going to occur sexually so here we've got a flower right which we know is the reproductive sex organ all right so when we come to reproduction in flowers it's the sex organ of the flower now have a look at our next one here they talk about the seeds right seeds are the result of sexual reproduction when the male and the female fuse so our second point seeds are produced okay and seeds are only produced if you have a male and the female so there we have telling us sexual asexual right etc now vitable mickey's living dams that can easily dry up towards the end of a hot dry summer remember they said only 14 degrees nice and cold explain how the plant is adapted to survive now remember what we said when we go back to this concept right we looked at the concepts of seeds the seeds are collected and left in the water but a seed can remain dormant for a long time so it says explain how the plant is adapted right it has a seed it forms a seed should i say what does the seed have around it it has a seed coat that can protect it and what else do seeds do they can re remain dormant that means they can just sit there until conditions right until conditions are favorable or better i'm going to write that because then writing favorable is going to test my spelling so this concept again of a seed is produced during sexual reproduction how is the seed all right dispersed remember i said to you one of the things about the seed is it can go far away from the parents guys weed water blue machis right there we go water blomicky where are they so what is going to take it away it's going to be the water right just looking into things seeing if you can understand that concept okay the next concept where the next question we're going to look at is about a potato now potato these words that you've got here look here there's a rhizome we know is an underground stem right here is a flower so again we are looking at asexual and the flower going to be a means of sexual reproduction remember what i said to you plants don't necessarily have one now this concept of the flower i've taken out of the question but you would need to know that next segment we're going to look at the flower so you would need to be able to label it as i said the interconnectedness of all the questions okay let's read the question the potato tuber tuba we know asexual all right produces eyes which then grow into new plants so we know asexual reproduction the plant grows in area stem which give rise to flowers look at the same concept again that range in color from light to dark purple the plant will also grow an underground stem that will develop new tubers asexual reproduction some variety of potatoes flowers self-pollinate we're not going to look at it now when we look at the question on pollination basically means it pollinates itself right green round poisonous fruits are produced after flowering and each fruit contains about 300 seeds so again we're looking at the potato right how it can undergo sexual and asexual now if we go again it says to us discuss how the potato undergoes asexual reproduction so we go and we have a look guys and we can quote directly from the text the potato tuber produces eyes which planted growing to new plants so asexual reproduction it's got tubers and on those tubers it has eyes and those eyes are going to grow into new plants right so again recognizing the word tubers the previous question was bulbs sexual reproduction two things again actually there's more than two right there's a few things that you could have taken here one it had flowers that produced fruit that is sexual reproduction or it produced seeds and it said when it got to the flowers it spoke about pollination which means taking the male sex cell to the female sex cell so we've got a whole variety right of references leading to sexual reproduction give two advantages of sexual reproduction in the potato all right advantages of asexual any of them could have been it's quick right it's less energy there's a whole list that we had right it is cheap okay favorable traits can be passed on quickly there was a whole lot that you could have used there and give any to advantages all right the last question would you eat the fruits the answer was no if we go back you'll see what did they tell you the fruit is poisonous right okay guys that is all that we have for today right so make sure you know asexual reproduction predictable sexual reproduction who knows what we will get until next time cheer bye [Music] you