Answer: A
Explanation: Vaccines create memory cells with a weak version of the pathogen, so when they meet that pathogen again the body can respond more quickly and more efficiently since they have already been exposed to the pathogen.
ANS:- DENSITY DEPENDENT FACTORS ARE THOSE WHICH AFFECT THE POPULATION GROWTH AS POPULATION AS A RESOURCE OPT(A) TRUE, AS…
The answer to your question is either drawbridge or scaffolding. I want to go with drawbridge because it has support and stands of for itself, so its similar to a stucture if that makes sense.
Euglenoid chloroplasts are surrounded by nuclear membrane
