Another solid episode, Professor Dave. Most of this is about 9th grade biology, but It has been a long, long time since the 9th grade. Nice refresher. Thanks!
A fun note is that the pollen in order to fertilize the ovule need to "burrow" through the cells in the stigma. They essentially push their way through the intercellular space between cells until they reach the ovule. The rather annoying part for humans is that the pollen has no way to tell which cells it comes into contact with so it will attempt to push its way through any multicellular structure it comes into contact with that will allow it to keep burrowing. Although skin is usually pretty resilient, the mucus membranes (like in our nose) are not, so pollen will frequently burrow into our intercellular space. They don't actually do any damage to us but often, our immune system will take the intrusion as a threat and begin an immune response as most infectious bacteria will do the same. The annoying part is that the antibody selected will almost without fail be the E type antibodies which stick their back ends into mast cells and trigger a signaling cascade when they come into contact with their recognized pollen. This causes the mast cell to release histamines which causes uncomfortable swelling and redness more commonly called an allergic reaction. The current best guess (at least when I was earning my bachelors) is that the original use of the allergic response was to parasites as the red itchy swelling would cause it to be difficult for a parasite to cling on to the skin as well as causing scratching which might dislodge the organism. One of the main statistics of note that increases the probability that this is the correct answer is that the countries which no longer have enough widespread use of modern medicine that the are no longer endemic or frequent parasite infections are also the only countries that have widespread problems with allergies. It is thought that, because it is no longer being used for its intended purpose of parasite removal, the allergen system is malfunctioning in identifying nonharmful invaders like pollen as a threat Edit for a last note: Eosinophils (a type of white blood cell) are also found at the site of these anti-parasitic/allergenic responses but we currently have little understanding as to how they act and what their job is but they are thought to be the innate immune system's parasite specialist cells somehow geared towards damaging the multicellular bodies of parasites. I say somehow because, at least when I studied immunology, the mechanism for how they do this is unknown
aha, so the allergy is the body mistaking pollen for a parasite. the joke is on the pollen, which is looking for another plant's lady bits. all a tragic misunderstanding. ...the pollen is technically trying to fuck our noses, lol.
Really like your videos but the cactus shown is a photosynthetic stem not a leaf ( likely genus Cereus) Most cactus spines( I read not an expert) are modified leaves or bud scales. Prickly pears have tiny leaves on new shoots that dry up in a few weeks. Pretty sure there are some in the cactus genus with "real" leaves but it is not real common. White potatoes are modified stems not roots i am 99 % sure.. ( think sweep potatoes are modified roots but wouldn't risk anything valuable to bet on that. )
@Professor Dave Explains You're a great teacher, and all of these science lectures are both valuable and appreciated. But you know what the people want.
His top three videos total 22 million views - that's called feedback. His top four videos are all Flat Earth, hardly a coincidence given the staggering number of videos on his channel. With those, he did something right. He has the tools to debunk the nonsense and he's a master at it. If he just became the new Thunderf00t he'd be more popular than Thunderf00t.
What is a starch exactly, just a complex carbohydrate? What kind of cell structure do tubers have? Is it storage for the next generation or is it returned to the parent plant?
Starch is a collection of polymers of alpha glucose that differ only in their degrees of branching, check out my biochemistry tutorial on polysaccharides for more information.
I did wonder why I didn't see the flower. A slight miss there. I wasn't aware they where wind Pollinated as some can grow a fair way from others. And I see bees on them all the time
your explanations are so brief, but very clear. Thank you. Teachers in my nation lack the ability to explain teaching materials simply like this. Maybe I can make explanation based on your videos, or translate your teaching videos into Indonesian, if I may. I think that would be useful for students in Indonesia :D
4:27 just thought I'd mention here that those are not leaves on cacti, those are stems that have been modified for water storage and photosynthesis! The leaves of the cacti were modified into the spines , hence why the stem had to modify to be photosynthetic. Succulents on the other hand, do have modified leaves for water storage.
Perennials can be deciduous... Perennials are plants that live year on year (like trees and stuff). These are contrasted with "annuals" which carry out their entire lifecycle within a year. Deciduous trees lose leaves. These are contrasted with Evergreen trees, which do not lose their leaves. I know you probably don't care as this comment is over a year old... I'm just commenting so anyone else who reads it has a chance to learn :)
Well if by "get into" you mean have a career in science, then the first thing to do would be to get a bachelor's degree in some scientific field. If you just meant that you want to learn some things, then look no further! My tutorials are all you need.
_Dayoo couldn’t have said it any better it’s a sign of either innate stupidity or the failure of the educational system that this much is effort is put to disprove what is scientifically sound. Imagine if that same energy was put towards advancing or developing models for a variety of inquiries.
So are plants that have ryzomes all one organism? For example the grass in my area has these. So is one root and ryzome all one big plant and if so is there a limit to the size of one plant?
You are much much intelligent please make a complete series on course PLANT ANATOMY(explains axial ray systms n flower development etc) videos of undergrad level
4:28 "fat wax covered leaves on succulent plants like cacti".....aren't cacti known for having modified spine leaves and storing water in their stems ...?
Your intro really brings me a lot of joy, Professor Dave. :)) Just wanted to point that out :>
Another solid episode, Professor Dave. Most of this is about 9th grade biology, but It has been a long, long time since the 9th grade. Nice refresher. Thanks!
u are right
*Interesting video.* Could you also do videos on *SOIL* ? I feel this topic is neglected in popular science channels - yet so important.
I second this
@@elihyland4781 me too. Oh shoot, I'm the OP.
Soil needs an entire series
@@jollyjokress3852 got stoned and rewatched 3:30am and almost recommented the same thing🤙🙆🪂
A fun note is that the pollen in order to fertilize the ovule need to "burrow" through the cells in the stigma. They essentially push their way through the intercellular space between cells until they reach the ovule. The rather annoying part for humans is that the pollen has no way to tell which cells it comes into contact with so it will attempt to push its way through any multicellular structure it comes into contact with that will allow it to keep burrowing. Although skin is usually pretty resilient, the mucus membranes (like in our nose) are not, so pollen will frequently burrow into our intercellular space. They don't actually do any damage to us but often, our immune system will take the intrusion as a threat and begin an immune response as most infectious bacteria will do the same.
The annoying part is that the antibody selected will almost without fail be the E type antibodies which stick their back ends into mast cells and trigger a signaling cascade when they come into contact with their recognized pollen. This causes the mast cell to release histamines which causes uncomfortable swelling and redness more commonly called an allergic reaction. The current best guess (at least when I was earning my bachelors) is that the original use of the allergic response was to parasites as the red itchy swelling would cause it to be difficult for a parasite to cling on to the skin as well as causing scratching which might dislodge the organism. One of the main statistics of note that increases the probability that this is the correct answer is that the countries which no longer have enough widespread use of modern medicine that the are no longer endemic or frequent parasite infections are also the only countries that have widespread problems with allergies. It is thought that, because it is no longer being used for its intended purpose of parasite removal, the allergen system is malfunctioning in identifying nonharmful invaders like pollen as a threat
Edit for a last note: Eosinophils (a type of white blood cell) are also found at the site of these anti-parasitic/allergenic responses but we currently have little understanding as to how they act and what their job is but they are thought to be the innate immune system's parasite specialist cells somehow geared towards damaging the multicellular bodies of parasites. I say somehow because, at least when I studied immunology, the mechanism for how they do this is unknown
aha, so the allergy is the body mistaking pollen for a parasite.
the joke is on the pollen, which is looking for another plant's lady bits.
all a tragic misunderstanding.
...the pollen is technically trying to fuck our noses, lol.
A very good video to learn both English and Biology.
Congrats on a million subs soon. Very well deserved, keep making more vids :) I love the way you break things down
Really like your videos but the cactus shown is a photosynthetic stem not a leaf
( likely genus Cereus) Most cactus spines( I read not an expert) are modified leaves or bud scales. Prickly pears have tiny leaves on new shoots that dry up in a few weeks. Pretty sure there are some in the cactus genus with "real" leaves but it is not real common. White potatoes are modified stems not roots i am 99 % sure.. ( think sweep potatoes are modified roots but wouldn't risk anything valuable to bet on that. )
Thank you for the lectures even during lockdown professor
@Meloveulongtime are you from Mars or pluto
your channel and startalk are a godsend on youtube.
Thank you for the content!! I am so happy to have you teach about plants in this video, fantastic! Thanks Dave 😊
i really like ur videos
they do help me in my school syllabus
@Professor Dave Explains
You're a great teacher, and all of these science lectures are both valuable and appreciated.
But you know what the people want.
His top three videos total 22 million views - that's called feedback. His top four videos are all Flat Earth, hardly a coincidence given the staggering number of videos on his channel. With those, he did something right. He has the tools to debunk the nonsense and he's a master at it. If he just became the new Thunderf00t he'd be more popular than Thunderf00t.
What is a starch exactly, just a complex carbohydrate? What kind of cell structure do tubers have? Is it storage for the next generation or is it returned to the parent plant?
Starch is a collection of polymers of alpha glucose that differ only in their degrees of branching, check out my biochemistry tutorial on polysaccharides for more information.
@@ProfessorDaveExplains I see. I will do, thank you.
you also show a dandelion seed head in the middle of your flower conversation, exemplifying anemophyly - what you show is anemochory
I did wonder why I didn't see the flower. A slight miss there. I wasn't aware they where wind Pollinated as some can grow a fair way from others. And I see bees on them all the time
Dave explains everthing so clearly!
Thank you Dave, very well explained
Thanks bro this made me learn more about plants then 2 months worth of biology (plants) that my prof miss teach
... damn you're life-saver for my biology final exam 😂😂❤️ if only I knew about you before..
thank you tomorrow is my presentation an you save me
Can anyone tell me, is there a difference between the term carpel and pistil?
Yeah there is. There are multicarpellary pistils as well.
Thanks!
Wow thanks for this lesson
good work sir.
cool video. Potatoes are stem tubers but your graphics seem to suggest they are root tubers.
Thank you teacher
your explanations are so brief, but very clear. Thank you. Teachers in my nation lack the ability to explain teaching materials simply like this. Maybe I can make explanation based on your videos, or translate your teaching videos into Indonesian, if I may. I think that would be useful for students in Indonesia :D
4:27 just thought I'd mention here that those are not leaves on cacti, those are stems that have been modified for water storage and photosynthesis! The leaves of the cacti were modified into the spines , hence why the stem had to modify to be photosynthetic. Succulents on the other hand, do have modified leaves for water storage.
Well understood... thanks for that 😇☺️☺️
0:32
"shoot system"
Me: *golden laser pew pew*
Taraxacum officinale as wind-pollinated less showy flowers... ... seed head, an odd mistake, oops : ))))))
thanks a bunch!
Thanks a lot
Professor Dave, doesn’t the illustration in the insert at 01:55 show a deciduous tree instead? I thought perennials didn’t drop their leaves.
I was just showing the passing of the year with that image, in retrospect I can see how that's quite confusing.
Professor Dave Explains I appreciate your response. Your videos are amazing.
Perennials can be deciduous...
Perennials are plants that live year on year (like trees and stuff). These are contrasted with "annuals" which carry out their entire lifecycle within a year.
Deciduous trees lose leaves. These are contrasted with Evergreen trees, which do not lose their leaves.
I know you probably don't care as this comment is over a year old... I'm just commenting so anyone else who reads it has a chance to learn :)
i've learned easily from your videos
god bless you
Professor Dave please correct the cactus story - you show shoots and call them leaves! this way I cannot recommend your nice video to my students.
Maybe your math playlist should be named “Math With Professor Dave”
starch storin' stubers!
rising rhizomes!
i'm not high!
Do you have any tips on how to “get into” science with no background in science what so ever? Where to start
Well if by "get into" you mean have a career in science, then the first thing to do would be to get a bachelor's degree in some scientific field. If you just meant that you want to learn some things, then look no further! My tutorials are all you need.
Professor Dave Explains Thank you!, i’m 14 so i can’t get a bachelor degree yet.
Ah, well then high school first!
Professor Dave Explains oh yeah, i am already watching your general chemistry playlist and it’s super interesting!
yo dude the green parts on cacti are stems not leaves, the leaves are the spikes
rootin' shootin' tootin'!
i still love rewatching the flat earther video's. proffesor dave just ABSOLUTELY ANIHILATED that community. LOL
as he should. those idiots should be shamed at all time.
@@lionablaze8747 exactly XD
@@gabogonzalez9428 yeah? Dave responded to the responses and once again, completely outplayed those idiots.
I second this
_Dayoo couldn’t have said it any better it’s a sign of either innate stupidity or the failure of the educational system that this much is effort is put to disprove what is scientifically sound. Imagine if that same energy was put towards advancing or developing models for a variety of inquiries.
I understand you more than my teacher, l appreciate ❤
hi sir , your such a great help.. allow me to call all your posts are heroic
Tubers are not a part of the roots, rather a modified stem
Shoot, it looks like there are stem tubers and root tubers, so the tutorial should have specified.
So are plants that have ryzomes all one organism? For example the grass in my area has these. So is one root and ryzome all one big plant and if so is there a limit to the size of one plant?
More plants!
Nice👍
You are much much intelligent please make a complete series on course PLANT ANATOMY(explains axial ray systms n flower development etc) videos of undergrad level
4:24
Is that a pawpaw?
Im trying to grow them in my backyard with my dad :)
great
wait tubers are modified stem not roots.
فرٹیلازیشن کے بعد پھل پودے کی Ovary سے پیدا ہوتا ہے ۔۔۔۔۔کیا یہ معلومات درست ہیں؟؟؟؟
Great video 📹.
Ps nice haircut 💇🏻 👍
I want to join willibe able to go to the lessons I need to. Cover again
you can view anything you wish at any time just go to my home page
Does cancer infect tree
sir i had miled you to do world history plese do look on that sirr this vedio is super thank you hope you do
i definitely will do world history at some point but probably not for a while
@@ProfessorDaveExplains sir really happy to see your replay for me thank you for your pleasure replay sir . i will be waiting for that. thank you
4:28 "fat wax covered leaves on succulent plants like cacti".....aren't cacti known for having modified spine leaves and storing water in their stems ...?
Examples of eudicots who doesnt show secondary growth
can you Explain how cannabis works and why
that's covered a bit in my biopsychology series and will moreso in my pharmacology series
@@ProfessorDaveExplains thank you ...
🎉🎉
Dave in. D.
Arnt rhizomes the worst? I hate all those weeds that do this.
TYG
I like u most
wooow my comment is in top 15
1st
You're starting to look like the younger of the two Jehovah's Witnesses that comes around my house once a year. Good video anyway.
:)