The answer for this question would be Integument, digestive, respiratory and urogenital.
The largest system that contact with the external environment would be integument and digestive. That makes two system has normal flora of microbes and not sterile like the other systems. Normal flora of microbes will prevent the pathogen microbe grows so it gives some benefit.
No that is just, no just no. DNA is copied through cell reproduction where a cell splits to create more (growing for multi called organisms and asexual reproduction for single celled organisms) The mitochondria is an organelle that is the "power house" of the cell, the "digestive system".
Answer:
Orange skin
Explanation:
Incomplete dominance with the genotype Yy results in a combination of the dominant and recessive traits. In this case the combination of yellow and red skin would be orange skin.
C 50%
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