Top answers

Biology
A Level

Describe the synaptic transmission of a nerve impulse

-action potential arrives at the axon terminal 

-voltage gated calcium ion channels open (due to the influx of sodium),

-calcium ions diffuse into the synaptic knob

-synaptic vesicles...

PB
Answered by Phoebe B. Biology tutor
2862 Views

Describe and explain how the lac Operon allows E coli bacteria to adapt to a new environment.

E. coli normally metabolise glucose, but if glucose is not available in a new environment, the lac operon can allow E. coli to metabolise lactose, the sugar found in milk using the structural genes beta-g...

CE
Answered by Charlotte E. Biology tutor
11772 Views

What is the difference between DNA and mRNA?

DNA and mRNA are both nucleic acids and are made up of a sugar, phosphates and a base. However, they are very different. Firstly by simply looking at the molecules DNA is double stranded whereas mRNA is s...

EC
Answered by Emma C. Biology tutor
5949 Views

Explain the role of the diaphragm in breathing out

The external intercostal muscles contract which moves the diapraghm upwards. This reduces the volume of the thorax and therefore with less space, the pressure in the lungs goes up. The pressure in the lun...

KA
Answered by Kai A. Biology tutor
13292 Views

What happens to the rate of an enzyme-catalysed reaction when temperature increases? And when pH changes?

As temperature increases, the molecules involved in the reaction gain kinetic energy, increasing the chances of collision between the substrate molecules and the active sites of the enzymes, a step that i...

MD
Answered by Maria D. Biology tutor
11905 Views

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