Nerve cells communicate by sending an electrical signal through an axon, from this molecules get released into the synapse this then binds itself onto receptor sites. With ion-linked channel receptors, the ligands get binded to a protein. The ion channels are then opened and the proccess gets repeated. Does that help?
After having one concussion you are more likely to have another — some doctorsestimate you increase your risk up to three times. There are two reasons why your risk increases: carelessness and brain chemistry.
Answer: <u>The spine</u>
Explanation:
In the study of animal anatomy,a landmark is a major point on the body that has biological significance. An anatomical landmark is a biologically-meaningful point in an organism.;these landmarks are used for the definition of corresponding anatomical points within species.
Posterior, describes a region that is at the back of the body.
Answer:
The correct answer is b. The oldest generally accepted fossils of large animals range in age from 565 to 550 million years old.
Explanation:
The oldest one of them all is the hematite tubes, that are dated about 3.77 billion to 4.2 billion years and it's from a yet unknown bacteria.
Looking at the onion root tip under the microscope you can see large, rectangular cells with visible distinct cell walls surrounding it (cells have a more regular shape because of the wall). Inside the cells, you can notice darkly stained nucleus, large vacuoles at the center and sometimes small granules within the cytoplasm. Looking the onion root tip under the microscope is often the way to observe mitosis. Usually, you cannot see organelles such as mitochondria, ribosomes, rough and smooth endoplasmic reticulum, centrioles and Golgi body as they appear translucent and because are too small to be seen under the light microscope (electron microscope required). Also, chloroplasts are not present in an onion cell because it is not a photosynthetic cell.
