I think number one is b and number two is D.
I hope this helps!
<span>cytoskeleton is composed of globular proteins placed in a way similar to chains, ou queues. they are only few types of these globular proteins, and they dispose following precise patterns. actin and tubulin are made of actin subunits and a- and b-tubulin alternating subunits respectively.
antibodies are proteins too. they are composed by two regions. one is common to all antibodies, one is specific for interaction with a substrate through a mechanism of the kind key-and-lock.
to locate where actin and tubulin are in a cell, you can simply construct specific antibodies. you just have to keep the common part of the antibody and bind to it a chromophore (a molecule capadble of emitting fluorescence if irradiated with light at a specific wavelenght). then you have to bind to this part a suitable "lock" for actin or tubulin. you can only do this if you know the structure of actin and tubulin and their phisical properties, which can determine what kind of interactions they can establish with precise molecules.</span>
A because unlimited resources if a lot of value
The important<span> point is that the </span>surface area<span> to the volume ratio gets smaller as the </span>cell<span> gets larger. Thus, if the </span>cell<span> grows beyond a certain limit, not enough material will be able to cross the membrane fast enough to accommodate the increased </span>cellular<span> volume.</span>
