Because of their high rate of mutation. They also can be hard to track because they infuse their DNA into your body cell DNA and can lay dormant and undetected for years.
1 goes with d
2 goes with c
3 goes with b
4 goes with a
5 goes with e
<span>Many traits require the concerted action of multiple genetic loci, often in combination with the environment.</span>
1.Most aquatic animals have fins or paddles that help them swim
2. Skin is usually slippery and soft
