Search our library of homework questions

Top answers

All subjects

All levels

During succession the species present changes. Explain why.

The pioneer species (or any other species) changes the environment, making it less hostile. Also some species are better competitors and out-compete others.

Answered by Alfie B. • Biology tutor

8000 Views

A student wishes to investigate the effect of surface area on the rate of reaction between marble chips and hydrochloric acid. Which variables should he control?

Concentration of HCl, Mass of marble chips (use excess HCl).

Answered by Alfie B. • Chemistry tutor

4102 Views

How is structure relevant to enzyme function?

Enzymes are functional proteins which are used to catalyse reactions. They all exhibit primary, secondary and tertiary structure, and some which have more than one polypeptide chain have quaternary struct...

Answered by Alec M. • Biology tutor

22648 Views

Expand the following expression: -5x(x-7)(x+3)

Expansion of the given expression will result in x to the 3rd power, as there are 3 parts involving x, multiplied together. Let's ignore -5x for a second, and multiply the two expressions in brackets (usi...

Answered by Matas S. • Maths tutor

4591 Views

The curve has equation y = x^3 - x^2 - 5x + 7 and the straight line has equation y = x + 7. One point of intersection, B, has coordinates (0, 7). Find the other two points of intersection, A and C.

As both equations are equal to y, we can combine them to create a single equation in terms of x: x^3 - x^2 -5X + 7 = x + 7. Shift the equation so the left hand side is equal to 0 on the right: x^3 - x^2 -...

Answered by Alfie B. • Maths tutor

7166 Views