The Reproductive Lives of Nonvascular Plants: Alternation of Generations - Crash Course Biology #36

Hank introduces us to nonvascular plants - liverworts, hornworts & mosses - which have bizarre features, kooky habits, and strange sex lives. Nonvascular plants inherited their reproductive cycle from algae, but have perfected it to the point where it is now used by all plants in one way or another and has even left traces in our own reproductive systems.
Table of Contents
1) Key Traits of Nonvascular Plants 01:42
2) 3 Phyla of Bryophytes 02:52
3) Alternation of Generations 04:33
a) Gametophyte Generation 05:04
b) Sporophyte Generation 05:25
c) In Vascular Plants 07:48
References:
news.nationalgeographic.com/ne...
kidsresearchexpress.blogspot.c...
facultyweb.wcjc.edu/biology/BI...
www.sumanasinc.com/webcontent/...
en.wikipedia.org/wiki/Alternat...
www.bio.miami.edu/dana/dox/alt...
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[@nicolejajaja2199]

Can't stand at the fact that this was released 8 years ago.

[@13mcrgirl]

Recommend you watch the whole video, but if you're in a rush to just get the idea of alternation of generations start at 4:50

[@forest3620]

You're my hero

[@Howf]

yes. yes. yes It was such a wise decision to dump the lengthy textbook after 5 minutes to watch this! So much easier to understand. Thank You, Hank. Thank You.

[@crashcourse]

You are correct! Added an annotation, thanks for letting me know. Not sure how that slipped through.

[@coloredpandas1993]

The animation of mosses really helped me understand how mosses reproduce! I had 2 labs and a whole lecture over this and the 3 minute clip of this taught me more than the 3 hours I spend in lab and lecture. Many thanks!!

[@gibcote]

A small correction: The capsule holds 1000s of "haploid" spores, not "diploid". :) Loved the video! Great job with the animation!

[@oksay523]

My science teacher loves you and even assigned your videos as homework. She also likes to watch them in class. Nice videos, good job making them interesting and appealing to all ages. :)

[@CloseAirSupport]

They are great at that

[@phillpauley6672]

So your science teacher is paid to teach you by showing you KZbin videos? Damn. I’d be a great teacher in that case. I watch mostly sciency stuff that I could show kids... Wait... nope I don’t have the patience to deal with kids. Never mind.

[@khhnator]

no one expects the spanish moss

[@jvstAsYouAre]

I really really really like this comment

[@seanking4552]

Hank buddy, get me an A on my Bio test. I believe in you more than I believe in myself.... I shouldn't have played BF4 all night >

[@tjtbkgaming]

pffttt it's all about advanced warfare now

[@loccioillupo1013]

psshhh destiny is life.

[@tjtbkgaming]

loccio il lupo well buddy that's your opinion and i respect it :)

[@loccioillupo1013]

tjtbkgaming lol get a character to lvl 20 and you'll be hooked...

[@tjtbkgaming]

loccio il lupo i played destiny a lot until aw came out i have a lvl 29 hunter, i stopped playing the day aw came out and haven't touched it since then.

[@ariahjohnson5972]

I feel like Crash Course should rightfully be sponsored by Google.

[@lichuo]

ariah johnson I don't care

[@antisepticeyeglitchy1434]

ariah johnson I agree with you the ariah johnson

[@garretiswright8532]

@@lichuo No one cares about the fact you don't care

[@megaKstudios]

they're sponsored by KZbin, which is a property of Google

[@ariahjohnson5972]

megaKstudios I was so young when I wrote this lol I learned you can make money off of KZbin since then and I’m 21 now 🤣🤣🤣🤣🤣 whoops!

[@astudyinmarkgatiss]

I have to take a biology final tomorrow and, as I couldn't sleep, I'm reviewing. I have trouble retaining information due to my head fog, so I was happy to see an easier learning method than books and notes: these videos. Thank you for these. :)

[@Drmario192]

You'll never know how happy I was to click on this review guide for part of my final to see my favorite SCI Show guy!! Instantly knew I was set. You da best!

[@krystalhendrix9983]

At 7:13 I'm pretty sure he meant to say haploid spore not diploid because spores coming from the sporangium are 1n.

[@faria5179]

yup..u r right..well noted!

[@singingdirt1127]

But spores have 2 sets of chromosomes...what am I missing?

[@tehreemafzal1630]

H

[@orlannetchienang4444]

It’s not an mistake they are diploid

[@alenoo]

They are 2N

[@kalebolson1310]

Hank, at 7:15 you made a mistake by saying that the capsule is full of diploid spores. While the sporophyte is diploid, the spores produced should be haploid.

[@RuadhanG]

No. The gametaphytes release haploid cells which upon arrival at the archegonia join creating a diploid cell which replicates itself through mitosis until there are thousands of diploid cells (spores) which the calyptra releases and the ones that land on wet ground become bryophytes.

[@Duckduck3000]

Ruadhan Glynn After fusion of the gametes in the archegonium, the newly formed diploid cells start replicating through mitosis (you're right uptil here) and form a sporophyte, the sporophyte then produces haploid spores through meiosis.

[@michaelkagan5451]

Demba Fofana Demba is correct. The spores couldn't possibly be 2n because they germinate on their own to create gametophytes which are n.

[@loona7126]

spores can be either haploid or diplod. Mitospores are haploid if made in haploid sporophyte or diploid if made on diploid sporophyte, meiospores are always haploid.

[@guyrukedineshgoonewardene4326]

THANK YOU I WAS A BIT CONFUSED AT THAT POINT

[@LilZombieFooFoo]

this video got me an A on my biology exam much thank such hank broooooooooo

[@aaronsilvera177]

Lil' Zombie Foo Foo Same

[@CurtisAmoy]

After falling asleep through a few mono-toned lectures, this quick video really tied my understanding together, thank you.

[@ChelseaMF13]

You know what I love? The fact that these biology crash course videos are following my biology course at school down to the T. I've got a bio test on thursday that I need to revise for... was feel pretty annoyed about that, but then I realised it gives me an excuse to watch crashcourse! :D

[@sydneynicholls8901]

This is so amazing! As he was talking my thoughts actually started to align surrounding all the textbook stuff I've read - he makes it so easy to understand!!! :)

[@KingArgonII]

These shows are fantastic. I love how you (Hank) and John present information. I hope you do more such as physics, because it is a misunderstood and a fun study.

[@brettito]

Next week - don't miss Hank explaining how grass grows! He makes everything entertaining!!! Keep up the amazing work!

[@loopieinfla]

I cant help but laugh! So refreshing to see humor and quick explanations for what may seem like complicated topics! Wonderful videos. My son and I truly enjoy them (13 yrs old). As a future Science teacher it is something I will share and link to my pages, thank you!

[@KLFD530]

Spanish moss is a plant,Tillandsia usneoides. We commonly refer to tillandsias as "air plants"...it is not a lichen.

[@grumpy_cat-gj7oy]

yee

[@grumpy_cat-gj7oy]

but i think at the time of making this video spanish moss was believed to be a lichen

[@catherineluckenbach5398]

Love this guy! Using his catalog of videos to teach our outdoor classroom in the Hamilton Gardens - good stuff!!!

[@mandydax]

When Hank explained the concept of alternation of generations, I immediately understood it thanks to the Aliens franchise. Facehuggers are like sporophytes. Yay!

[@reeeeenie]

so happy that i have this to help me study for my test tomorrow!

[@anarios8456]

Every video of yours I watch Hank I am just so grateful for, you make learning bio easy and straightforward, thank you!

[@NatureInspired1023]

Love the video! Was trying to review my knowledge of non-vascular plants and got a kick out of this while also accomplishing my goal. Thanks!

[@Moochiekoo]

I just wanted to say thank you SO much Hank for Crash Course Biology, because of it I passed my end of term Biology test in the top 10% of the year group, when last year I was in the bottom 10%! SCIENCE, OH YEAH.

[@tsharena120486]

Thanks for wrapping this up for me! I have so much more understanding of all of this now!

[@joeynichols8207]

Hey Hank, first of all, Thanks for all these great videos, they're helping a lot with the AP Bio test review. I have one question though, so if the gametophytes produce gametes through mitosis, how is genetic variation produced, how are gametes haploid, and how is gender detirmined? Thanks again for the videos!

[@Brielle2210]

This could possibly be my favorite response I've read in a long time. Thank you for making my day.

[@johnoko132]

These are such great episodes!! Please keep it up!

[@cosmizz]

Great Video Series I'm learning lots, though it can be a lots of information at once so I really appreciate visual aids and Crashcourse's are great when there used. I have to add this one was confusing, there are comparison and cycles and different processes, it hard to keep it all straight. I watched parts four times now (which I learn something each time) but I'm still missing something.

[@tfos993]

I know this video is old but I'd like to say that your channel has helped me so much through highschool. You make learning fun.

[@samanthamulder5515]

Hank, you actually just saved me for tomorrows test:) You are the best!!! Thank you soooooooooo much.

[@jocelynluna6190]

The examples of the ones that do not have a vascular system would be the liverworts, hornworts, and mosses but they have bizarre features for their reproduction systems but they need the requirement of water presented. They undergo gametophyte in which the sperm and egg meet and undergo mitosis then later releases spores into the air hoping it would fertilize another egg. - Great video!

[@FictitiousSkyxxo]

Thank you for this! I have an exam on this tomorrow. Do you have any quick tips on remembering the life cycles of gymnosperms and angiosperms?

[@aubreygreen5812]

This is so going to help me pass bio 2 lab and lecture I'm so happy !!!! 🤗

[@oliverwakelin3567]

Hank you are doing a fine job

[@ctrer8298]

Thank you! This was extremely helpful

[@minajeetjemineetje3002]

These videos are so amazing and Hank you are so funny! Thank you very much!

[@ChangGuo]

I feel smarter everytime I watch one of these videos.

[@sethb523]

How can something that seems so complicated in lecture be explained in like 3 minutes. Thank you!

[@annaam6675]

Shouldn't plant taxonomy use Divisons instead of Phyla? Anyway you saved my morning, I didn't feel like studying for my Botany test, but this is a good compromise ;)

[@thebeanlife4409]

you are my only hope at doing well on my midterm today. thank you for being here haha

[@kdk750]

Literally just stepped out of my algae/moss lab in my bio class. THANKS HANK!!!!!!

[@markopolo8910]

This cleared up a cloud of confusion! Thanks a ton!

[@MultiPaulinator]

Thank you. That one threw me through a loop, too.

[@jesspollock2152]

Yes I finally realized that after thinking about it for a while! Thanks :)

[@mahimabanana]

Instead of relying on my ancient textbook to do my independent study unit, I can come here and not be bored to death. Thanks for making it interesting, Hank! :D

[@GabrielaGarcia-fr7xq]

hey CC, at one point (5:41) you say the spores are haploid, and at (7:12) you say they are diploid. This is a pretty confusing topic so please fix. other than that, thank you sooo much for your collection of awesome videos! you're my hero!

[@vishrutiganesh7704]

+Gabriela Garcia The spores are actually haploids, in case you needed that. An easy way to remember it is how the fused gamete is diploid, so haploid spores are produced.

[@GleeVampDiaries212]

thank you! This stuff is actually quite interesting

[@zachyweezer]

so great. you've helped me more than you know! thanks!

[@nikkinuk5]

Thank goodness! Posted a day before our practicals and long tests *O* Thanks!

[@ianquinlan7947]

Thank you from me as well, Hank. Will be sad to see this end in four weeks. Would be excellent if you two could start a new series, but since this is offered to us for free? I have absolutely no right to complain if you don't.

[@Shetasen]

I swear Hank shows up in almost every science KZbin channel I visit.

[@DinaGrinsted]

I told my Biology teacher about CrashCourse Biology and we might start watching them in class! Hooray!

[@inchworm9311]

this was a good one

[@wanlitan7406]

6:07 is where it's at. Turn on the captions if necessary.

[@emmaskaar]

You've probably already realized this, but Crash Course puts out about one video a week on each active course. Biology and Ecology have ended and Hank is working on Chemistry now. (You can find the playlists at the Crashcourse page.) His brother, John, has finished World History and Literature, and is working on US HIstory. All the courses are worth watching. Have fun learning!

[@camarillomelissa]

Awsome video! Thank you! so much for uploading.

[@phoesmi5911]

This was in my classroom today! I fangirled so much lmao

[@rynsawyer4185]

+Phoebe Smith I would too if I were in your place!

[@jaynescott2577]

Very informative

[@Giga572]

My guy explained something my bio teacher would have taken 4hrs to explain and made me understand with in 20 mins frrrr

[@DJ_Dett]

Do you think you could (at some point) do a video on plants that seem to be geared entirely on very rapid reproduction and choking out all other plants? We have some non-native species on the Eglin Reserve that are very interesting and do this. They're generally a problem for the forest, as well as controlled burning (since they ignite like gasoline during fires).

[@cascochran583]

a long stalk with a cap on top called calyptra... beautifully helpful for remembering.

[@jessicamiller91]

Yeah thanks dude , with a lil back knowledge you helped me put this together

[@z4k4z]

Fascinating. The alternation of generations seems like a pretty effective strategy, combining the benefits of sexual reproduction (mutation) with the ease of asexual proliferation.

[@kittytsang468]

thank you so much crash course! midterm in four hours ; ^ ;

[@robobrain10000]

This is a good review for my IB Botany test for HL Bio.

[@GnarlandQuaver]

Thanks. Took my AP test today- NOTHING about ecology 90% of it was just graphs- and I saw EVERY video.

[@SodapopSays]

"The mosses... Mmmm, fuzzy." n_n

[@hamidgul7224]

Good job!

[@barrauines9761]

Thank you sooo much, you've just saved my biology test ^.^

[@Duckduck3000]

Nice video although at 7:21 you say that you need high humidity levels for spore release whereas dry conditions are actually needed ;)

[@SuperTheoryMan]

unexpected slide whistles make everything better

[@MzFoRi3]

This is amazing!

[@madbritishbelizian]

decomposer is normally a term used in relation to a wide range of organisms that break down organic matter as I'm sure you are aware, the partner in the litchen is in fact a photo-, or more often, a chemoautotroph.

[@asamikinomoto8517]

Hi! I wanted to know if nonvascular plants and vascular plants both had cuticles. I read on a few websites that they did have small waxy ones, but others say no. Thank you!

[@skyblazer7]

Hank! Why weren't you making these 20 years ago? Never mind, silly question. However I would have been inspired to pursue Biology (in more ways than the usual one, heh). You and your brother are brilliant presenters and teachers.

[@b.kkalita7708]

wow sir....ur videos r Vryy helpful....

[@missilesociety]

I literally have an exam on this tomorrow oh my god, thanks Hank!

[@mauradudley6573]

I am wondering if there is an error in this video - at 7:14 he says that the capsule is full of "diploid spores" - but aren't the spores haploid since they then go on to become a gametophyte?

[@oisiaa]

Only Hank could get me to click on a video titled "The Sex Lives of Nonvascular Plants: Alternation of Generations"

[@pizzagirl9908]

such a good teacher!!! random.. but i love the wanted!

[@BecauseJustBecause]

Such pretty scenery.

[@SweetBabyMonkeys]

Thanks for bringing romance to the scientific process! =D

[@jenniferscoby1363]

Love this just like all of the rest! Just found a tiny edit...can you put a word blip that says "haploid" in, where you talk about spores? The sporangium is diploid, but the spores, produced via meiosis, are haploid, not diploid. I'm sure it was just a verbal slip - bound to happen!

[@eyg24]

7:12 he means HAPLOID spores!!!!!!!!!!!! confusing but actually helped me learn it from getting confused and figuring it out

[@sugarpeepsez]

That was pretty cool! Thanks.

[@erehel]

I was looking for a way to procrastinate since this is the lazy person I am.Then I stumbled upon this gem here and voil´a!I can actually revise for my botany exam while kind of relaxing my brain at the same time!

[@SweetBabyMonkeys]

Yes!! It's learning time!

[@OlleLindestad]

Depends on what taxonomist you ask. Bryophyta, Anthocerophyta and Hepatophyta are all recognized as phyla or have been at some point. But yeah, unranked divisions are more common in botanical taxonomy these days.

[@uyariz9718]

Very Good Video's!

[@wadoom4001]

2019?????And btw i have an exam tomorrow

[@llindsey1121]

This is great!

[@crashcourse]

Yup. Are you gonna be ok?

[@alisaabary5224]

Thank you!

[@purpleducksauce]

Hank, can you do a botany series!?

[@sarahelizabethe1]

my god, you're so fabulous. Thank you so so so much for this.