We consider them to be made of 3 quarks, 'uud' for the proton<span> and 'udd' for the</span>neutron<span> where 'u' is the up quark and 'd' the down quark. ... Now, </span>protons and neutrons<span> are basically found at the atomic nucleus while </span>electrons<span> form the shell of the atom, moving around the nucleus.</span>
To calculate the water's salinity
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There are the drugs that are approved by the FDA (food and drug administration) </span>which is a federal agency of the United States Department of Health and Human Services, and it includes <span>most of the </span>drug<span> products that are approved since 1939.</span>
1. It is used to cure diseases that may harm or even kill us.
2. It is used to make transportation fast and easy.
3. It is used to understand the universe better to plan for the future.
4. It is used for fast and easy communication.
Answer:
C - Contains the embryonic disk
Explanation:
After an egg is fertilized, it begins to divide into smaller cells, from the 1 cell stage, to 2, to 4 and so on. Then, on the third day, the cells fall within 16-200 cells and it is then called a <em>morula</em>.
On the fifth day, the morula becomes a ball of calls which is now differentiated into an <em>inner cell mass and a trophectoderm</em>. The inner cell mass becomes the <em>embryo</em> as development goes on and the trophectoderm, becomes the <em>placenta</em>.
As development goes on further, the floor of the amniotic cavity is formed by the embryonic disk, a layer of prismatic cells derived from the inner cell mass.
The embryonic disc develops into 3 layers:
There is a major differentiation of cells which gives a template for the origin of development of specific organs of the embryo.
