Top answers

Describe how negative feedback is used to control blood glucose concentration (6 marks)

Throughout your answer to this question make sure that you are cramming as much key language into it as possible! Phrases like 'islets of Langerhans', 'beta/alpha cells', and 'transporter proteins' will all ...
MH
Answered by Matt H. • Biology tutor
21102 Views

What is the cardiac cycle?

The cardiac cycle is what happens during a single heartbeat. To understand the cycle it helps to know that the heart is made up of four chambers, the top 2 chambers are called the atria and the lower 2 chamb...
MP
Answered by Megan P. • Biology tutor
5094 Views

How does a deletion of a base in the DNA base sequence lead to a mutated protein?

It is important to note that bases on the DNA (and mRNA) are read in separate sets of 3s along a DNA/(mRNA) stand (this is called a triplet code in DNA, or the codon in mRNA). So, if a base is deleted, the w...
FS
Answered by Febi S. • Biology tutor
17538 Views

What are the events in the cardiac cycle?

The cardiac cycle is the series of events that leads to blood being pumped to the lungs and around the body. The cycle begins with the SAN (sino-atrial node). This is the hearts 'pacemaker'. It sends out a n...
TC
Answered by Thomas C. • Biology tutor
9181 Views

How do white blood cells protect us from infection?

Sometimes microorganisms are able to make it past the body's external defences (i.e. the skin) the body's immune system must defend the body. White blood cells are really important in the immune response. Th...
TC
Answered by Thomas C. • Biology tutor
25519 Views