Top answers


What is diffusion?

For the exams, the definition you will need to know is that "diffusion is the net movement of a substance from an area of high concentration to an area of low concentration, down a diffusion gradient&qu...
ER
Answered by Emily R. • Biology tutor
7679 Views

Describe the regulation of blood glucose level.

The glucose level is regulated in pancreas by negative feedback loop, which means that when there is too much glucose, it is removed from the blood, and when there's too little, it is released into the blood...
JO
Answered by Juraj O. • Biology tutor
9481 Views

Why do the muscles of the Iris contract and relax?

To alter the size of the pupil, so the correct intensity of light is allowed through. Enough light is let through to allow clear vision, but not so much light that the retina might become damaged.
CM
Answered by Calum M. • Biology tutor
9730 Views

What is an enzyme and what effect does temperature have on enzyme activity? (6 marks)

An enzyme is a globular protein that acts as a biological catalyst. They work by reducing the activation energy of chemical reactions, which increases the rate of reactions. All enzymes have an optimum tempe...
IO
Answered by Isabel O. • Biology tutor
16639 Views

What are the differences between mitosis and meiosis?

Mitosis and meiosis refer to the way cells reproduce. Mitosis sees the cell divide in two, forming two genetically identical diploid cells. The reproduction of cells means mitosis is used by the body for gro...
CW
Answered by Chris W. • Biology tutor
24499 Views