Well, 'bean' is not necessarily an exact term. Dehisce (literally 'gape' or 'break open') is the name given to the plants which protect their seeds in a pod of some sort, and which breaks open.
Thus Vanilla, Cocoa, broad beans, runner beans, and peanuts may all be called beans. But that's only my opinion. A botanist would differ no doubt.
A cocoa bean may be the largest in terms of weight, but I couldn't get a figure. My guess would be 1kg perhaps. They would be about one-half the size of a coconut, and contain dozens of small seeds each a little larger than a green pea.
My scarlet runner beans at home will get at least 300mm long if I let them proceed so. Broad beans only get up to 150 - 200 mm in my garden.
I understand that Vanilla beans grow up to 150mm long.
Bean is normally the seed itself. Look at the Wikipedia link below.
beans
name the two bean shape structures
Yes, a bean is a seed. It is a seed for a bean plant. Bean is often said in place of seed. I hope this makes it easier to understand. :)
A bean is a seed.
bean
Bean plants are seed producing plants
No you can not replace a bean nuclei with an olive seed.
The red kidney bean is a dicot seed because it has two cotyledons (seed leaves)
A jelly bean?
The bean is the seed of the plant.
You can see the cotyledons when the bean seed grows. I think you can't tell just by looking at the seed.
The seed of the coffee plant looks rather exactly like a coffee bean, because it is a coffee bean.
The seedcoat of lima bean is hard whereas it is membranous in peanut.