<u>Answer</u>:
Option 1.Eukaryotic cells first seen
Option 5. oxygen builds up in the atmosphere
<u>Explanation</u> :
- The name <em>Proterozoic eon</em> is derived from a Greek word which means earlier life.
- This eon represents the time just before complex life started proliferating on earth.
- One of the most important events that took place during this eon was <em>build up of oxygen in the atmosphere</em>.
The fossil evidence also shows the occurrence of <em>advanced single-celled eukaryotes.</em>
<em>So the events that define the Proterozoic eon are eukaryotic cells first seen and oxygen build up in the atmosphere. </em>
The answer is an internal orifice or internal os.
The cervix or cervix uteri refers to the lower portion of the uterus in the human female reproductive system. The openings are called the internal orifice and the external orifice of the uterus.
The internal orifice or internal os refers to the upper terminal of the cervix, which opens into the uterus. On the other hand, the external orifice refers to the terminal of the cervix, which opens into the vagina.
A crystals shape is determined by the arrangement of the atoms or molecules inside the crystal.
Your peripheral nervous system includes the bunch of nerves outside your brain and nerves outside your spinal cord. Your central nervous system includes your actual spinal cord and brain.
One thing you could have done is sat down to breakfast. Your peripheral nervous system sent the information about what you smelled to your brain, and also sent nerves impulses to your brain to bend your legs. Your brain, which is in the central nervous system, can distinguish different smells.
Answer:
A. Smell
Explanation:
Mechanoreceptors are known to primary sensory structures. Their function is to provide information about the mechanical characteristics of the internal and external environments. These mechanoreceptors usually detect stimuli such as pressure, vibration, sound and touch from the internal and external environments.
Smell does not rely on mechanoreceptors but rather rely on olfactory receptors.
