A change in the ratio of auxin to ethylene is what controls leaf abscission, abscissic acid plays a minor role in the process. It was named after a research on chemical changes that precede bud dormancy and abscission, in which they isolated the same compound and then named abscisic acid. The main role of ABA is inhibiting seed germination and inducing the production of proteins that help the seeds withstand the extreme dehydration that accompanies maturation.

Paul, I did not know you taught biology; I remember you as a cross country coach at KG high school. At the time I coached xc at Dodson High School. I have since relocated to Idaho. I stumbled onto your videos by accident and use them to support my biology classes. I am writing this to add some insight to the origin of the word gibberellin. I read in one of Isaac Asimov's books that the alchemist Jabir ibn Hayyan used shorthand to disguise his chemical experiments. His name in Greek was Geber and our word gibberish means nonsense or foolishness which is how we talk when we speak gibberish.

I've been interested in gardening over quarantine, and I just ran into this video! I remember using your videos when taking Biology I and II in university. Very nice to see you again, glad to see you're just as helpful as you were in my college days. Peace from California!

I remember that for roots cell elongation happens where there is less auxin. It does happen to elongated cells in the upper portion of the root but auxin does not move against gravity like you mentioned. Cell elongation is opposite that found in shoots. Min 3:20

I study in the U.K and all of his videos are super helpful!

Extremely helpful and simple video for great understanding and revision. Love it!

Bozeman...thank you so much! I'm not the best ap bio student (B/B+) but we watched your videos in class one day and I used them to study for my plant test. I got it back today and received a 95. You da man

Best regards from Slovenia. Thank you for all your videos.

I'm here because I didn't listen to my teacher, and it's my exam today:)))))), btw I love listening to your lectures, I've already watched some of your videos, and I'm subscribed.

Thank you! This really helped me so much.

Been struggling to learn all this from the textbook because it's so dry! Now I got all the information I need in just 8 minutes ✌🏼

Thank you very much! This video clarifies a lot of problems for me!

So eay to understand. Thank you so much! ❤

How fascinating! thanks a million for this video! 👏🏻👏🏻👏🏻🌿🌱✨

Love your work. Any chance the explanation of gravitropism in roots could please be corrected? That would really helpful for viewers' understanding. Thank you.

THANK YOU MR. ANDERSON, YOU HELP ME STUDY SO MUCH C:

Great video! Thanks.

Your video was very clear and helpful to help me study for my plant physiology exam tomorrow. Thank you! And maybe I'll put a ripe banana next to the apples next time when I buy some fruit. Just to test it haha. Very interesting! Greetings from the Netherlands.

I love the video, He explained exactly the information that i should to know.

Incredible explanation! Easy to understand! i was looking for good explanations out there about that, I reach you! Thanks!

This is great!

Very straightforward. Nice video

i dont know how to thank you you are so much simpler than my teacher i can understand your lectures thank you :)

You are the best teacher, Mr. Anderson

Full explanation in easy way 👍

Very helpful! Thank you very much!

Just a small comment on the gravitropism of a root. It is completely opposite way than you explain. In the root, more auxin is in the inner part of the bending and there are numerous explanations why it is different way then in the stem. Just a comment. For the simplicity, just stay with the explanation of stem phototropism, it is enough. But my biggest congratulation to your set of education videos, great job!

Your videos are so helpful I don't have to read and just watch ur videos and still get an A

Thank you very much you are a very thorough explainer i really cant tell you how much your videos are helpful

Thank you!!

Thanks so so much!!

thank god you exist ! thank you so much :)

Luv you videos! Thank you

you're the best. thank you

thank u i really needed this review

I don't think you're right about the part about auxin and if you lay down the root and auxin goes against gravity. In my biology class we learned that gravitropism isn't due to the auxins moving upward away from gravity and therefore causing the root to grow downward. We learned that auxin is going to move downward with statolith (starch granules) and a high concentration of auxin actually inhibits growth. This causing the bottom part to stop growing but the top part to continue growing, and causing it to bend. Because if you think about it, if auxin moves towards the shaded area and if you lay down a root, auxin isn't going to move up towards the sun, but down to the shaded area, also leading to high concentration of auxin causing inhibition of growth. I believe it's called The Falling Statolith Hypothesis.

The best teacher in solar system

Thanks!

Mr. Anderson, Excellent commentary on plant hormones. The one thing that I would add is that ethyleen is used in the fruit industry to "ripen" or "color up" fruit off of the tree fruit that is picked in an unripe state. Citrus is an example of this. I believe apples are also.

To make sure " That was helpul". Haha. Thankyou, it was a good explanation.

this is epic. cheers!

Thank you

good videos man. need to know the basics so can wonder about more advanced shit

You r awesome teacher

you are very eloquent

Now I can fall asleep in class during presentations knowing I still have Bozeman to learn from.

Botany final in two hours this helped a ton!

please upload a video on plant growth

whats are the difference between how plant and animal hormones operate?

I was wondering. The exampel you do with gravity, roots and auxins. Is that really true? Because i thought auxins in roots inhibit growth. And you're showing that the auxin moves on "the other side" of the gravity pull resulting in the side to grow, making the roots bend. Now i thought that the auxins would stay on the "gravity-pull-side" and inhibit that side to grow, and then resulting in the bend of the root.

I’m confused - does auxin actually trigger cells to grow bigger? OR, as he indicates at one point, does auxin loosen the tissues (cells?) causing them to relax and expand (making them bigger)???

you rock so much I hope I can meet you someday

You should mention that auxin slow down the growth of cells in roots,so that will make sense.

Hey Gudmundson and Green honors bio block 2🌸🌸🐣🐣🌻🌻🌞🌞

u know u speak too fast. ...at some part of yur explanation I was unable to catch some of yur words....:'(:-(:-(..I must say u really explained it nicely....thanx:-):-D

the first plant that u have explained auxin on ?

Damn you're so cool and smart to be from Montana.

How does Auxins affect growth? anyone that can send me a concept map of that?

This video should be called "Basically".

you, sir, have saved the whole junior/senior classes of troy high

it is gibberellia fujikuroi

Whens your untill dawn playthrough?

how many times can you say 'basically' in 8 minutes?

The bomb

Heyyyy everyone from Mr. Maschal’s class !!!!!!!

MISTER ANDERSON

HEY MS. COHN'S CLASSES

do you know de way

i don't really understand the difference between giberellins and ethylene-- don't they both help the fruit mature?

Whats that plant name please ?

Move to Boston/Cambridge or something...

giberella fujikuroi was the name of the fungus

1:56 "And basically what we found out is that auxin is a chemical." LOL

tHankssssssss

This video needs a bit of update.

Refers to plants as us, lol!

explanation abt auxin is wrong. gravitropic movement is not due to auxin movement towards lighted side instead it is due to auxin sensitivity of root cells, explained by falling stotolith hypothesis

Hello 5th period Ap bio class(Stiner)

smiling sun :D

Hello 3rd period AP Bio class.

Anyone here from ATHS Bani Yas campus?

first get LEARNED by someone then TEACH anyone...

Good brief overview but could you please stop using the word " basically" Thanks

@jestreal