Answer;
Primitive streak.
At the onset of the embryonic period, the primitive streak appears. It will eventually become the neural tube.
Explanation;
The primitive streak is a transient structure which forms on day 15 of human development.
It marks the start of gastrulation; the process in which the inner cell mass in converted into the trilaminar embryonic disc.
It originates from the anterior epiblast.
Answer:
Alyssa is observing two cells, X and Y. Each cell is from either a plant or an animal. She records some of her observations in a chart.
cell X and cell Y
one has chloroplast the other does not
food vacuole is big in one while it is smaller in the other
Explanation:
C. The vestigial structures. <span>A </span>vestigial structure<span> is an anatomical feature that no longer seems to have a purpose in the current form of an organism of the given species. Often, these vestigial structures were organs that performed some important function in the organism at one point in the past. However, as the population changed due to</span>natural selection<span>, those structures became less and less necessary until they were rendered pretty much useless. While most of these types of structures would probably disappear over many generations, some seem to keep being passed down to offspring even though they have no known function.</span>
The autonomic nervous system is responsible for regulating involuntary body activities.
<h2>The nervous system coordinates the bodily functions of muscles to produce actions.</h2>
Involuntary activities such as circulation, heartbeat, digestion, breathing, and peristalsis for example are generally not under our conscious control.
These are otherwise known as involuntary actions controlled by the autonomic nervous system which in turn is a subdivision of the peripheral nervous system (this system branches off the spinal cord to all other parts of the body.
Other parts of the nervous system would be the central nervous system divided into:
To learn more about the nervous system see: brainly.com/question/13487019?referrer=searchResults
#SPJ12
