<span>Organisms used to be classified in the earliest times according to their size. As science progressed, they started getting organized by their physical traits and now they're organized by traits found in their species that are not found in others based on the theory of evolution. They are classified according to how they developed from a starting organism.</span>
Answer:
The chance of a normal couple having a child with down syndrome is 1 to 600 births.
Explanation:
Down syndrome is a genetic flaw that occurs when the fetus is being formed.
A human cell considered normal has 46 chromosomes, divided into 23 pairs. For some unknown reason, an error may occur at the beginning of embryonic development and an extra chromosome is created, which binds to par 21. The result is cells with 47 chromosomes. This causes the said syndrome.
It is important to know that this failure happens at random. It is nobody's responsibility. It has not been proven to date that lifestyle, actions during pregnancy, smoking, drinking, medicines, environmental factors or kinship between the couple can influence this occurrence. She is not contagious either. The likelihood of a normal couple having a child with the syndrome is approximately 1 to 600 births.
interlocking calcium carbonate plates is the answer.
Chromatin is the threadlike form of genetic material in the nucleus.
(chromatin coils around histone proteins and form chromosomes when mitosis/meiosis are going to occur)
The ductus arteriousus is a blood vessel that connects the pulmonary artery to the descending aorta. Otherwise known as the ductus Botalli, this structure pumps blood into the fetus' non-functioning lungs from the right ventricle. This blood vessel will close at birth and becomes the ligamentum arteriousum.
