Answer:
The correct answer is - variables that they didn't control and not enough replicates
Explanation:
In this particular case, Pablo and Johanna using too many variables in their experiment or research, All the variables used, are not controlled and with time these variables can not be replicated again on experiment groups.
They did not select a particular age or weight of dogs, the diets are different and they feed dry kibble to only one dog. There are so many variables and for a better result experiment, all variables should be controlled only the independent variable is permitted to manipulate.
Answer - Propagation
Reasoning - Growing New Plants from other plants part is called Propagation. In the case of such as using the roots or part of it stem to induce into a citrus tree. Which is called Grafting.
Neuron
Neuron can be defined as excitable
cell that usually carries, processes and transmit impulses or electrical
signals. Thus, they are known to be basic unit of the nervous system which
includes the spinal cord and brain. However, the signals between s neurons occur
via certain connections called synapses.
Noble gases have a complete outer shell meaning they have eight valence electrons (octet rule); having eight electrons makes the atom very stable and unlikely to react because they don't need anymore electrons.