GCSE Biology - Structure of a Leaf and Stomata #50

In this video we cover how plants are organised, and then take a closer look at the leaf. We consider the different parts of a leaf and how it is adapted for its functions.

We re-uploaded this video as the original had some unedited footage left in it. Sorry!

[Cognitoedu]

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Amadeus & Tom

[corvidcryptid]

THANK YOU to my teacher for sending me here. I don't like Biology normally, but I love these videos!

[noah]

Funny how half the comments of people complaining about school. Really though, these are good, I learn stuff from them.

[urfavlolobaji]

For anyone who needs to learn the definitions for this lesson here ya go


Wilts:the plants leave and stem droop due to lack of water

Turgid:rigid cells that are full of water. The vacuole pushes against the cell walls

Transpiration: the flow of water through a plant

Xylem:a hallow tube that carries water and minerals to its leave

Stoma(plural of stomata):allows gases to exit or enter

Stomata: water evaporates and escapes

Flaccid:flaccid cells are floppy so they can’t hold up a plant

Guard cells: each of pair of curved cells that surrounds stoma

Dont worry guys I needed to write it somewhere since I memorized them soo I thought it will be useful for you Guys too 💖💖

[Matt-xhwq]

Post-Video Quiz:
1. What do the xylem do?
2. What do the phloem do?
3. What is a waxy cuticle and what does it do?
4. How do stomata know when to open and close?
5. What are meristem cells?

[twishagirisankar]

Your simple straightforward explanation really helps. Thank you :)

[marvolord]

thanking my teacher for sending me here bc they sound like tom riddle 😌 will gladly listen to this

[yourdailydoseofsalt]

Hey guys. I had done my Biology A Levels 6-7 years ago. and through lack of practice, I've forgotten so much of the basic information.

I know it feels like a drag right now, but make sure to knuckle down and consolidate this info, and hopefully you won't forget like I did. But, you're never too old to learn!

Best of luck to any of y'all going through your GCSEs!

[ksumar]

Absolutely fantastic 👍
Quick simple and concise explanation.
I admire your intro diagram of
Cells ▶️ Tissue ▶️ Organs

[chansclown]

I appreciate this channel so much, it has saved lives




I hope you read this

[cityzeneditzz]

For anyone that needs to learn this for a test or somein here very usefull


the leaf is a plant organ
tissues in leaf;

| upper epidermis -- protectes the surface of the leaf
Transparant allows light to pass through for potysnthesis
Waxy cuticle covers this, it's an oily material reduces evaporation/ prevents the leaf from drying out


| lower epidermis -- contains stomata
stomata allows carbon dioxiede to enter the leaf and oxygen to leave
controls the amount water vapour that can pass out the leaf
on the sides of the stomata you can find gaurd cells


| palisde mesophyll -- contains palise cells these are packed with chloroplast
chloropast contains clorophtyll which absorbs light need for photosynthesis


| Spongy mesophyll -- these have alot of airspace that allows co2 that diffuse from the stomatathrough the spongy mesopyll
to get to the paslise cells Oxygen dose the opposite and comes from the palisde cells to the spngy meospyll then to the stomata






| Xylem -- transports water from roots to the stem and leaves. some water is then used for photosynthesis
also transprts disolved mineral ions likes magnesum used to make chlorophyll


| Phloem -- trasnports disolved sugars from leaves to the rest of plant the sugars are produced my photoysnynthsis
sugars can be used for lika glucose used for respiration



Definations

Wilts:the plants leave and stem droop due to lack of water

Turgid:rigid cells that are full of water. The vacuole pushes against the cell walls

Transpiration: the flow of water through a plant

Xylem:a hallow tube that carries water and minerals to its leave

Stoma(plural of stomata):allows gases to exit or enter

Stomata: water evaporates and escapes

Flaccid:flaccid cells are floppy so they can’t hold up a plant

[ereshkigal]

you just summarized in 10min what it took my teacher two weeks to teach.

[karimikei]

I would ve died from stress if I didn't binge ur vids before my exam

[ParissHaze]

No because as someone with a science teacher with a freaking HEAVY SWEDISH ACCENT, this is so much easier to understand, THANK YOU🙏🙏

[LivzonlinePG]

I swear we learnt about this in like year 7 but here we are again ig

[Bell-frxg]

Leaf: Leaves are where photosynthesis takes place, and it requires Carbon dioxide & water. The water comes from soil through the roots and xylem. List of components in the leaf:

Lower epidermis: first level in which carbon dioxide diffuses. Stomata & cell guard are here.

Stomata: it allows carbon dioxide to enter the leaf and oxygen to leave. 

Cell guard: controls when the stomata opens and when it closes. If there's a lot of water in the plant cell guards will open more and allow more carbon dioxide to enter. They close at night time when photosynthesis isn't taking place.

Spongy mesophyll: a level in which carbon dioxide goes through and contains a lot of air gaps between cells so that the gas can diffuse easily into the next level.

Palisade mesophyll: where photosynthesis occurs, since the palisade cells are full of chloroplasts.

Upper epidermis: the last level, very transparent so that light can pass through to get to the chloroplasts in the palisade cells.

Phloem: carries the sugar molecules to the rest of the plant after photosynthesis.

Xylem: brings water up from the roots for the palisade cells to do photosynthesis.

[vikisonline]

Epidermis- easy
Palisade mesophyll- perverted men
Spongy mesophyll- send many
Epidermis- easy
Guard cells- girls
Stomata- selfies
…that’s how i remember it

[ptfkxfx]

so if the plant was at night that means that the stomata will be closed because there ain t no sunlight to absorb and be able to photosynthesise am i right

[harithmustafa]

thinks you are the beast teacher in the interiate, and I am undear stand .

[jaba]

could you explain how potassium ions cause stomata to open (if they do) ? And also, if there are other factors that could affect guard cells swelling or becoming turgid?

Great video.