Because an antibody is "made" relative to the antigen, but kept at low levels when you are exposed the first time ("primary immune response"). The second time you're exposed to the same antigen, memory cells recognize it and the body produces a high level of antibodies, and the level of antibodies usually remains higher for a longer time ("secondary immune response"). This is your basic immune response (primary and secondary).
This explains exactly why vaccines are effective to extremely effective.
Have a control. You have to have something to compare your experimental results or else your results could be random chance.
5 is adaptation, 7 is transpiration
The both decrease genetic variation
Answer:
Unisexual and bisexual organisms are differentiated based on the reproductive systems they posses. Unisexual organisms have separate sexes male or female. Male and female reproductive systems are present in different individuals hence unisexual organisms produce male or female gametes but never both. Bisexual organisms have both male and female reproductive systems within the same individual. Hence, they are capable of producing both types of gametes. Some flowers are unisexual, and they possess only pistils or stamens. Some flowers are bisexual, and they possess both stamens and pistils together. This is the difference between unisexual and bisexual organisms.