Top answers

Biology
All levels

Why is surface area to volume ratio bigger in smaller animals and vice versa?

In surface area to volume ratio (SA:Vol) we are comparing the outside surface area of an object to its internal volume. So imagine 3 rubber balls, one's small, one's medium, one's large. The smallest ball...

CN
Answered by Charlotte N. Biology tutor
84248 Views

What is a protein and what functions can a protein have?

A protein molecule is a polymer which means it is built when lots of smaller molecules join together in a chain, like building blocks. These smaller molecules are called amino acids. There are are 20 diff...

JT
Answered by Joanna T. Biology tutor
4472 Views

What evidence is there for evolution?

For IB Biology, there are three types of evidence for evolution you need to know: fossils, selective breeding and homologous structures.

Fossils are preserved remains or traces of organisms from th...

EF
Answered by Emma F. Biology tutor
11035 Views

describe how the plant hormone auxin and light affects the direction of growth of plants

The hormone auxin causes cells in shoots to grow faster, and cells in roots to grow more slowly. Auxin becomes more concentrated on the side of the plant that is not facing the light, the shaded side. In ...

ND
Answered by Niamh D. Biology tutor
18879 Views

How is selective reabsorption acheived in the kidneys?

In the cells lining the proximal convoluted tubule, sodium-potassium pumps present in the membrane in contact with tissue fluid pump sodium ions out of the cells. This lowers the concentration of sodium i...

NS
Answered by Nianqi S. Biology tutor
14019 Views

We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2026 by IXL Learning