"Skeletal muscles" is the one <span>probable source of these muscles among the choices given in the question. The correct option among all the options that are given in the question is the second option or option "B". I hope that this is the answer that you were looking for and it has come top your help.</span>
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1. The genetic material is a good evidence of evolution because it's been conserved through time but with some slight differences.
Another important aspect is the </span><span>mitochondria.</span><span> The mitochondria resulted from a symbiotic relationship
between bacteria and pre-eukaryotes. Explaining why the </span><span>mitochondria looks like a bacteria and has </span><span>bacterial DNA.
2. specialized cellular modifications:
There are cellular modifications happening in multicellular organisms. That means, they have different types of cells, with different functions and will express different characteristics. For example:
- </span><span>Nerve
cells have
dendrites which is important to receive the electrical signal from another neuron, other cells don't have that.
- Sperm cells have a tail ( </span><span><span><span>flagellum) in order to swim through the vagina and no other cell has that.
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Here is the answer that you are looking for:
External Regulators<span>. </span>External regulators<span> are also </span>proteins<span>, but they react to stimuli from outside the cell. They direct cells to either speed or slow the cell cycle based upon outside conditions. For example, one </span>protein<span> reacts to molecules on the outside of a neighboring cell.
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I hope this helps out for you
I think the parietal cells have canaliculi which secretes it
The phospholipid bilayer has two hydrophilic surfaces: the extracellular and the intracellular surfaces. These two layers sandwiches a major layer of lipids or fat. Because of this nature of the lipid bilayer, water-soluble or <em>hydrophilic</em> hormones cannot enter the cell membrane. They have to rely on the mechanisms of receptors.
One can find transmembrane proteins embedded across the whole length of the lipid bilayer. One of the functions of these proteins is to serve as the link for hormones such as the ones given above. When the water-soluble hormones attach to one of these receptors, the receptor will be activated and send down a signal to the intracellular environment; these signals will then travel down towards their target site and eventually activate whatever it is the hormone was made for. One example of these transmembrane proteins are <em>G-coupled proteins; </em>examples of signals that cascade down the cell are cylic AMP and cyclic GMP.
