The infants length increases by 10%
The 20 minute physical activity I performed was doing yardwork. It was fairly easy to do, besides a lot of bending down involved to pick up sticks. I did it in my front and backyard for a bit over 20 minutes, and no one did it with me.
Answer:
antibodies
Explanation:
The third line of defense is specific resistance. This system relies on antigens, which are specific substances found in foreign microbes. Most antigens are proteins that serve as the stimulus to produce an immune response. The term "antigen" comes from ANTI-body GENerating substances.