Interactive Resources for Schools
This topic takes on average 25 minutes to read.
There are a number of interactive features in this resource:
Chemistry
Biology
Human biology
PSHE / Citizenship studies
Remember: 1 millionth of a metre (m) is 1 micrometremicrometre
1000nm.
(μm).
Humans are multicellularmulticellular
Made up of more than one, usually many cells.
organisms. That means they are made up of billions of individual cells. These cells are not all the same. There are many different cell types that are specialised to perform the range of functions needed in a complex organism.
As new cells grow and replicate, they become specialised to do particular jobs. Nerve cells that carry electrical signals, muscle cells which generate force and pancreaspancreas
An endocrine gland which produces insulin.
cells making insulin are just a few examples. Amazingly, all of these cells have grown from just one single fertilised egg cell.
Cells like these line the windpipe or trachea. The cell membranemembrane
A thin, flexible sheet-like structure that acts as a lining or a boundary in an organism.
is folded into tiny hairs which can move and push dust particles out of the lungs.
Many types of cancer, including those of the stomach, lung, skin and bowel, start off in epithelial cellsepithelial cells
Cells that cover the internal and external surfaces of organs.
. These cells line your organs and tissues and are exposed to environmental influences which, over time, can cause cancer to arise. For example smoking and lung cancer, ultraviolet radiation and skin cancer.
Substances can cross the cell membranemembrane
A thin, flexible sheet-like structure that acts as a lining or a boundary in an organism.
by diffusiondiffusion
The spreading out of the particles of a gas or any substance in solution down a concentration gradient.
, osmosisosmosis
The movement of water through a partially permeable membrane down a concentration gradient from a dilute solution (where there is a high concentration of water) to a concentrated solution (where there is a relatively low concentration of water).
and active transportactive transport
The process which uses energy to move substances against a concentration gradient or across a partially permeable membrane using a special transport protein.
. Use the animation to see how each of them works.