The answer is D because the layers all the way at the bottom had to be there for other layers to be built on top
Answer:
Pyramidal decussation is at the junction of medulla and spinal cord.
Explanation:
Pyramidal decussation may be defined as the the fibers that cross the corticospinal tract from one side to the junction and the other side to the central nervous system.
Pyramidal decussation is the point at the junction between spinal cord and medulla. The motor fibers crosses the midline from the medullary pyramids.
The frequency <em>p</em> of the yellow (A) allele is <em>p</em>= 0.3
The frequency <em>q</em> of the blue (a) allele is <em>q= </em><em>0.7</em>
Hardy–Weinberg equilibrium, states that allele and genotype frequencies in a population will remain constant from generation to generation. Equilibrium is reached in the absence of selection, mutation, genetic drift and other forces and allele frequencies p and q are constant between generations. In the simplest case of a single locus with two alleles denoted A and a with frequencies f(A) = p and f(a) = q, the expected genotype frequencies under random mating are f(AA) = p² for the AA homozygotes, f(aa) = q² for the aa homozygotes, and f(Aa) = 2pq for the heterozygotes.
p²+2*p*q+q²= 1 p+q= 1 q= 1-p
yellow (p²)= 9%= 0.09 p= √0.09= 0.3
green (2*p*q)= 42%= 0.42
blue (q²)=49%= 0.49 q=1-0.3= 0.7 <em>or</em> q= √0.49= 0.7