Top answers

How does translocation occur in the phloem?

Active transport occurs at the source, loading assimilates e.g. from photosynthesis in a leaf. This is carried out by specialised companion cells, via active pumping of hydrogen ions out of the cell, and cot...
JL
Answered by Julie L. • Biology tutor
7183 Views

What are the structural and functional differences between arteries and veins?

Arteries have a much thicker muscular layer than veins, as this allows them to contract strongly and generate a high pressure to allow blood to be quickly transported to tissues in the body. Arteries also ha...
AR
Answered by Anita R. • Biology tutor
3383 Views

How does an action potential work?

Resting potential at - 75mV Stimulus causes opening of sodium channels and influx of sodium ions, membrane becomes less polarized Threshold potential reached at -55mV, opening of many more sodium channels, g...
CH
Answered by Catherine H. • Biology tutor
3385 Views

What is the electron acceptor used in photosynthesis

NADP
BS
Answered by Bianca S. • Biology tutor
3258 Views

Describe the differences between hydrophobic and hydrophilic signalling.

Hydrophobic signalling molecules can pass through the lipid bilayer of the membrane due to both being hydrphobic. Once within the cell, the molecule can bind to a receptor or transcription factor to inhibit ...
LA
Answered by Lindsey A. • Biology tutor
11688 Views