C. If your hypothesis is proven then it eventually becomes true. The exact definition for scientific theory is an explanation that can be proved with repeated explanation.
Motor neuron disease includes loss of motor neurons in the anterior horns of the spinal cord and motor nuclei of the lower brain stem.
Answer:
A Y-chromosome
Explanation:
Males have one X and one Y chromosome
A
A haploid cell formed in the male seminiferous tubules
The reproductive tissues of male and female humans develop similarly in utero until a low level of the hormone testosterone is released from male gonads. Testosterone causes the undeveloped tissues to differentiate into male sexual organs. Primitive gonads become testes; other tissues produce a penis and scrotum in males.
Large organisms include...
Mammals (Mammalia)
Stem-mammals (Synapsida)
Reptiles (Reptilia)
Dinosaurs (Dinosauria)
