![Tilia stem cross-section](/sites/default/files/styles/resource_card_image_360x300_/public/2020-01/Tilia-stem_plant_cells.jpg?itok=5uh7WQ1j)
Plant Cell Structures and Functions
Backgrounders
Learn about the many different structures that make up plant cells as well as what differentiates plant cells from animal cells.
![Leaf and the Sun](/sites/default/files/styles/resource_card_image_360x300_/public/2020-01/Plant_Functions.jpg?itok=60gbqGFi)
Plant Functions
Backgrounders
Learn about the important plant functions of photosynthesis, respiration and transpiration
![Screen capture from video "The Wacky History of Cell Theory”](/sites/default/files/styles/resource_card_image_360x300_/public/2019-09/screen_shot_cell_theory.png?itok=XaFJP-YW)
The Wacky History of Cell Theory
STEM Explained
It took several scientists building on each other’s discoveries to come up with Cell Theory - one of the cornerstones of biology.
![Red-haired woman](/sites/default/files/styles/resource_card_image_360x300_/public/2019-09/red-haired_woman.jpg?itok=E7j3ahqo)
The Chemistry of Redheads
STEM Explained
Learn how chemistry and genetics makes redheads stand out from the crowd.
![Water droplets on succulent leaves](/sites/default/files/styles/resource_card_image_360x300_/public/2019-09/Succulent_leaf.jpg?itok=55kCziIw)
How Do Plants Survive in the Desert?
STEM Explained
Plants need to exchange gases and water with their environment as part of photosynthesis. Some plant cells have evolved specifically for this purpose.
![Mitosis of kidney cells © Ian P Newton & Paul L Appleton [CC BY-SA 4.0], Wikimedia Commons](/sites/default/files/styles/resource_card_image_360x300_/public/2019-08/600px-Mitotic_MDCKs.jpg?itok=VLMyMgJd)
What is Mitosis?
Backgrounders
Mitosis is an important part of cell division that helps organisms grow and repair themselves.
![Finger with a drop of blood](/sites/default/files/styles/resource_card_image_360x300_/public/2019-10/Finger_with_a_drop_of_blood.png?itok=9rIlbgSt)
The Immune Response
STEM Explained
When you cut your finger, your immune system kicks in to protect you from pathogens.
![Cartoon mammoth](/sites/default/files/styles/resource_card_image_360x300_/public/2019-10/Cartoon_mammoth.jpg?itok=yPc7tmR_)
Should Scientists Clone Extinct Species?
STEM Explained
Cloning makes it possible to bring extinct species back to life. But is that a good idea?
![Former Canadian astronaut Robert Thirsk enjoys cycling on board the ISS](/sites/default/files/styles/resource_card_image_360x300_/public/2019-09/Robert_Thirsk_cycling_on_ISS.jpg?itok=YDleE__K)
Spaceflight and Bone Loss
STEM Explained
Astronauts can experience bone loss in space. To understand why, you need to know a bit about how bones are formed and maintained in your body.
![Great tits eat from a bird feeder](/sites/default/files/styles/resource_card_image_360x300_/public/2019-10/Great_tits_bird_feeder.jpg?itok=aiRpq_-G)
Natural Selection in Your Backyard
STEM Explained
A study on bird feeders and beak sizes shows how an everyday human activity can affect the evolution of another species.
![DNA "unzipping"](/sites/default/files/2019-10/DNA_unzipping.png)
How can I obtain a sample of DNA?
Hands-on Activities
Be a biochemist! Learn how to extract DNA from an onion and find out what DNA looks like.
![Lacks historical marker in Clover, Virginia](/sites/default/files/styles/resource_card_image_360x300_/public/2019-09/Henrietta_Lacks_historical_marker.jpg?itok=pUlVzPub)
Why is Henrietta Lacks Important?
STEM Explained
When the cells of Henrietta Lacks were collected by medical researchers after her death in 1951, it changed the future of medicine.
![Hand with screwdriver “repairing” DNA](/sites/default/files/styles/resource_card_image_360x300_/public/2019-09/DNA_repair.png?itok=jwH_hm9z)
DNA Damage and Repair
Backgrounders
This backgrounder explains the different ways that cells repair damage to DNA.
![Massive algal bloom](/sites/default/files/styles/resource_card_image_360x300_/public/2019-09/massive-algal-bloom.jpg?itok=pqgXB2yc)
Eutrophication: Why you should care about pond scum
STEM Explained
When fertilizers from agriculture get into lakes and rivers, big problems can result for aquatic ecosystems, food chains & webs!
![T cells and cancer cells - Image © Meletios Verras, iStockPhoto.com](/sites/default/files/styles/resource_card_image_360x300_/public/2019-09/T%20cells%20and%20cancer%20cells.jpg?itok=H8EzjFj9)
Can Your Own Cells Cure Cancer?
STEM Explained
When a person has cancer, CAR-T Therapy uses their own cells to destroy the cancer cells in their body.