Antibodies are produced when the body is exposed to

Antibodies are produced when the body is exposed to a pathogen. Antibody production is a function of the specific immunity arm of the immune system.

During the first encounter with a  pathogen, antibody production against that pathogen is  a  bit slow and not very vigorous. However, memory of that pathogen is kept in memory cell which are a type of lymphocyte.

On a second encounter with the same type of pathogen, the immune system specifically remembers the pathogen and the response this time round is faster,  very vigorous, specific and  very effective.

Vaccines follow this principle, making good use of immune memory.

ans.

gregor john mendel is known for study of inheritance in pea plants. he used garden pea plant for his study, having alternative traits for various characters. he performed cross-breeding in pea plants to check how characters are transmitted between parents to offspring, such as cross between pure tall and pure dwarf plant. mendel studied the inheritance patterns in pea plants for various generations.

thus, the correct answer includes options and f).

c should be the answer