Answer:
central nervous system
Explanation:
The central nervous system is made up of the brain and spinal cord which carry out the function of processing information about the environment using the five senses and sends out your bodies response. such as if your finger touched the hot stove, that signal gets sent to your brain which sends a signal to your spinal cord telling your arm to pull away from the hot surface
Let say, polled (without horn) parent cattle is dominant (PP) and parent horned cattle is recessive (pp). They cross bred which produced all polled calf F1 generation. F1 will be hybrid for trait horn (Pp). On Selfing of F1 progeny ( Pp x Pp) will give 1 homozygous polled (PP) cattle, 2 heterozygous polled (Pp) cattle and 1 cattle with horn recessive (pp) in F2 generation.