Answer:
The three major internal parts of a stem are the xylem, phloem, and cambium. The xylem and phloem, as mentioned before, are the major components of a plant's vascular system. The cambium is a meristematic tissue, which means that it is a site of cell division and active cell growth.
Explanation:
I Believe the answer is DNA so answer choice C
I'm almost certain that the answer would be X and Y
Hoped this helped!
When animals are fighting over resources the number of one animal might decrease because the other animal would've tried to kill it and stay alive
when there is competition the population size of one animal might decrease while another increases<span />