This is a legacy topic. View the most up to date content by selecting the exam board in the dropdown to the left.
Gas exchange in large multicellular organisms is achieved by organs which have a large surface area and so are able to successfully provide the substances the organism needs in order to survive. In humans this is achieved by the lungs. But how does the oxygen acquired by the lungs actually reach every single cell of the body? A network of sorts is needed to do that. Many bigger and smaller tubes would come in handy. They would form like a… circulatory system. Oh wait, that’s precisely what mammals have: a circulatory system made of arteries, veins, capillaries, etc.
Plants, too, have a vascular (tubular) system. It is made of xylems and phloems. Yes, complicated names which you will love to learn about in the following topic (The Passage of Water through a Plant).
The key thing is that this circulation of a large amount of substances via a system of transportation is called mass flow, hence mass transport. Just more technical terms for you to learn, which describe something that really couldn’t get any simpler. Water, gases chillin’ through tubes in an organism.
I bookmarked the site
translucent The Student Room
Good topic notes and cool videos. I'll definitely recommend it to my students.
Seema Sehgal AQA Examiner and biology teacher on LinkedIn
You're such a G. Helped me so much, finally found someone who breaks biology down into something I can understand!!!
Alex Contact Form
Thank you for the help, your website and videos are awesome
pika mart YouTube
I got A* in A-level biology (Cambridge), thanks! I love your videos
Sherif Negm Facebook