Because few things about the human eye have changed throughout the course of human evolution. The entire human race learned to become truly bipedal, yet after millions of years, we still cannot see in the dark (like actual night vision). We still only have three cones/ color receptors in our eyes, the same range of unique eyes colors (controlled by melanin), shape and disorders. The human eye never even grows during your life; it is the same size when you are born to the day you die, with the exception of some deterioration. The nonexistence of change is why it is not considered evolution; to humans, there was no need for change as we had developed other ways to survive.
<span>The Cell Membrane. All living cells and many of the tiny organelles internal to cells are bounded by thin membranes. These membranes are composed primarily of phospholipids and proteins and are typically described as phospholipid bi-layers.</span>
Earth's crust is made<span> up of mostly oxygen, silicon, aluminum, iron, calcium, sodium, potassium and magnesium.</span>
When a signal molecule binds a membrane receptor, different intracellular events occur in response. Option D is correct: All of the above.
<h3>
What is signals translation and how is it done?</h3>
Signal translation is the conversion global process of extracellular signals into intracellular responses. This porcess is done by a translator.
Translation might be
- INDIRECT ⇒ <u>Second messengers</u> participate in the signal translation, mediating between receptor and the cellular response.
The receptor-ligand union causes the production of second messengers that will activate effector proteins. Occurs an amplification of the signal.
- DIRECT ⇒ Occurs directly in the membrane.
<u>Ionic channel proteins</u> are activated and can change the chemical signal into an electric signal through ion flow.
When the molecule binds receptors that are associated with enzymes -or acting as enzymes- or to G proteins, it occurs a conformational change in the receptor cytoplasmic domain.
This change triggers an intracellular signal cascade in which many molecules participate and several<u> chemical changes</u> occur.
According to this framework, all the options are correct,
- The receptor can open an ion channel in the cell membrane.
- The receptor can act as an enzyme causing chemical changes in the cytoplasm.
- The receptor can cause the formation of a second messenger.
So te correct option is Option D. All of the above.
You can learn more about membrane receptors at
brainly.com/question/19371673
brainly.com/question/703787
D. Mass consumption
is the answer