Need help badly thanks.
Down Syndrome is
A.a sex-linked trait
B.a recessive trait
C.the result of having two few chromosomes
D.the result of having an extra chromosome
1 answer
https://www.google.com/search?source=hp&ei=NvlRXOvZMc70swXamY7ICg&q=cause+Down+Syndrome&btnK=Google+Search&oq=cause+Down+Syndrome&gs_l=psy-ab.3..0j0i22i30l9.1887.4610..5327...0.0..0.118.682.5j2....2..0....1j2..gws-wiz.....0..0i131j0i10.j_7xDc9CvAI