Arrange these components of the mammalian immune system as it first responds to a pathogen in the correct sequence
pathogen is destroyed
lymphocytes secrete antibodies
antigenic determinants from pathogen bind to antigen receptor on lymphocytes
lymphocytes specific to antigenic determinants from pathogen become numerous.
only memory cells remain
i -> iii -> ii -> iv -> v
iii -> ii -> i -> v -> iv
ii -> i -> iv -> iii -> v
iv -> ii -> iii -> i -> v
iii -> iv -> ii -> i -> v

The correct order is III -> IV -> II -> I -> V

Explanation:

During the initial immune response, the antibodies present on B-lymphocytes binds to the antigenic determinant or epitope present on the pathogen.

This interaction between pathogen and lymphocyte trigger the production of more lymphocytes specific to the particular antigenic determinant. These B-lymphocytes then differentiates into memory B cells and plasma cells. Plasma cells secrete the antibodies against the pathogen.

These antibodies destroy the pathogen by making the pathogen recognized by phagocytic cells or by activating the complement system of the body and at the end, only memory cells remain in the body which is used to generate a quick immune response in subsequent infection. Therefore, the right answer is III -> IV -> II -> I -> V.

with pass cost = $25

without pass cost = 3x number of days going the the class

organisms that lack symmetry are called asymmetrical and belong to phylum porifera/sponges.

organisms with specialized stinging cells belong to phylum cnidaria. stinging cells are called cnidoblast cells.

cnidarians show two morphological forms : polyp (sessile) and medusa (mobile)

filter feeding is observed in porifera members.  

alternation of generation is observed in coelenterata or cnidaria. there is alternation of asexual polyp form and sexual medusoid form. it is also referred as metagenesis.