Top answers

Biology
All levels

If a gene mutation is associated with the development of Alzheimer's Disease (e.g. E280A), how might a high frequency develop in a population and why wouldn't natural selection decrease it?

A high frequency of mutation can be produced by having a small population, leading to high levels of inbreeding. When there is little interbreeding with different populations, the genetic diversity will r...

CR
Answered by Caitlin R. Biology tutor
2804 Views

How can DNA mutations alter the structure of a protein?

Regions of an organism's genome that code for proteins are known as genes. The sequence of deoxyribonucleic acids (bases) in a gene directly translates to the sequence of amino acids in the protein it enc...

LB
Answered by Lewis B. Biology tutor
3827 Views

Describe 2 ways in which the body prevents entry of microorganisms into the body

-acid in the stomach kills any pathogens-skin acts as a physical barrier to pathogens-hair in the nose and ears trap any pathogens -saliva & mucous trap pathogens. The bronchi have villi that help mov...

SH
Answered by Sara H. Biology tutor
4210 Views

Describe the pathway of electrical activity in the heart during the cardiac cycle.

The wave of excitation originates in the sinoatrial node in the right atrium. From there, it travels through the right and left atria, causing contraction of the atria (atrial systole). It is prevented fr...

JW
Answered by Josh W. Biology tutor
3578 Views

What happens in the light dependent reaction in photosynthesis?

Background Photosynthesis is the process where energy from light is used to break apart bonds in water . Hydrogen from water is then combined with CO2 to form glucose which ...

HW
Answered by Hannah W. Biology tutor
2703 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