VCE Biology Question Thread

[swagsxcboi]

What is the difference between pathogenicity and virulence.

They both seem pretty similar to me, so I am having a hard time distinguishing between the two.

Any examples would be appreciated!

you don't need to know these terms

[maurlock]

Why are insulin and glucagon called signalling molecules?

[gohfish]

Why are insulin and glucagon called signalling molecules?

Because they are molecules that signal a cell to respond in a particular way.

[popoy111]

Are glucagon and insulin signalling molecules because they attach to target cells and cause a series of events to occur within these cells?

[howlingwisdom]

Are glucagon and insulin signalling molecules because they attach to target cells and cause a series of events to occur within these cells?

Yeah and they also cause a change in cell activity

[popoy111]

Name the target tissue in which insulin and glucagon act on. And their effect in each case?

[vox nihili]

Name the target tissue in which insulin and glucagon act on. And their effect in each case?

There are heaps

[Jason12]

what's the definition of action potential, threshold and refractory period, synapse transmission and post synaptic neurone? I have a general idea but no real definition i could write down on the sac

[katie101]

In what ways are plant hormones different from animal hormones?

Thanks guys

[howlingwisdom]

Animal hormones act much more rapidly than plant hormones.
Animal hormones usually travel through the bloodstream whereas plant hormones travel through the phloem or xylem or even in the air (like ethylene, since it's a gas). 
Animal hormones aren't necessarily produced in response to environmental factors, whereas plant hormones are always (or almost always) produced in response to some environmental factor.
Plants don't secrete hormones from glands, whereas most animal hormones are secreted by ductless glands.

[walkec]

Name the target tissue in which insulin and glucagon act on. And their effect in each case?

Insulin - acts on cells to increase the uptake of glucose from the bloodstream into the cell. This lowers glucose concentration in the blood.
Glucagon - acts on the liver to convert glycogen into glucose to be then released into the bloodstream. This will increase glucose concentration in the blood.

[Reus]

do explants photosynthesise?

[walkec]

do explants photosynthesise?

What even is an "explant"?

[Reus]

What even is an "explant"?

Literally it's name. Ex - plant. A part of a plant (typically stem) or pieces of tissue that is cut off from the plant and placed in isolation to observe any growth (tissue culture)

[vox nihili]

Literally it's name. Ex - plant. A part of a plant (typically stem) or pieces of tissue that is cut off from the plant and placed in isolation to observe any growth (tissue culture)

If they grow they have to.