These preparations are called Vaccines. A vaccine is a biological preparation that provides active acquired immunity to a particular disease. A vaccine typically contains an agent that resembles a disease-causing micro-organism and is often made from weakened or killed forms of the microbe, its toxins or one of its surface proteins.
Answer:
Option a
Explanation:
A eukaroytic cell contains more organelles than prokaryotic cells, and it is much bigger and complex.
hope this helps and is right :)
C. "connect the brain to spinal cord"
hope this helps
Answer:
Ecosystem engineers are species that modify their environment in a significant manner, creating new habitats or modifying existing ones to suit their needs.
The mass number is the sum of the number of protons and number of neutrons the atom has.
So, we can write the equation as:
x + 20 = 40
x = 20 neutrons.
