Down syndrome is characterized by cells having three copies of chromosome 21. as a somatic cell in an individual with down syndrome prepares to enter mitosis, how many chromatids would be present in the cell’s nucleus?

after receiving a stimus, the sensory receptors send(s) signals to the appropriate area of the body.  

the must be sensory neurons.  

hope its .

any abiotic or biotic factor in an ecosystem that causes a population's size to slow or decrease is a limiting factor.

the cladogram shown here shows similarities and differences among several classes of vertebrates. anatomically, the four have limb structure as their common ancestor. we might separate the mammals from the other three classes because they a) divergent; do not lay eggs b) identical; are warm-blooded c) varied; a four chambered heart d) homologous; have mammary glands