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Describe the mechanism of transport in the phloem, involving active loading at the source and removal at the sink.

The active transport of hydrogen ions out of the companion cells using ATP creates a hydrogen ion gradient.This causes the facilitated diffusion of H + ions back into companion cells. This occurs through a c...
JC
Answered by Jonathan C. • Biology tutor
23336 Views

Describe the process of the reflex arc.

The reflex arc is activated to create a rapid response in order to maintain safety. It is an innate, automatic response to a dangerous stimulus. It involves 3 neurones. A sensory neurone, a motor neurone and...
RS
Answered by Ria S. • Biology tutor
15417 Views

How is DNA structured?

DNA stands for deoxyribonucleic acid. Two polynucleotide (which means nucleotide polymer) strands are twisted together and form what looks like a ladder - the DNA double helix . These two strands run antipar...
SH
Answered by Sadie H. • Biology tutor
3306 Views

Explain how ATP is generated from reduced NAD and reduced FAD via the electron transport chain?

Reduced NAD is oxidised at the first carrier of the electron transport chain and reduced FAD oxidised at the second. The free electrons move into the system of carriers within the membrane while the protons ...
LG
Answered by Lewis G. • Biology tutor
19771 Views

If you're measuring an environment using a quadrat or another sampling instrument - why can't you just do it where you see the most biodiversity?

Taking a sample from an area of space where you can clearly see there to be more species richness or abundance is not taking a representative sample, and it won't tell you what is really going on in that par...
EC
Answered by Ellie C. • Biology tutor
6584 Views