Question

A Collateral host is
(a)Crop host
(b)Additional plant on which life cycle is completed
(c)Grass host other than the main host
(d)Alternate host

Answer 1

The type of host varies depending on the parasites and their needs. A host can be either acting in secondary or in an intermediate manner. This host usually is from the same family as that of the primary host and the parasite cannot survive without this host.

Complete step-by-step answer:
A Collateral host is an additional plant on which the life cycle is completed. The hosts other than the usual host on which the pathogen can complete its life cycle are called collateral hosts. For example; The conidia produced on these hosts serve as inoculum for the next season. Such inoculum can infect the rice plant at any stage.

Additional Information:

Collateral Host	Alternate Host
-A wild host of the same family.	-The wild host of other families.
-For off-season surviving a pathogen.	-For the completion of the life cycle of the pathogen.
-To bridge the gap between two crop seasons.	-Host compulsory required
-Example: paddy blast-panicum repens.	-Wheat black stem rust-barberry leaves.

We have discussed the differences. Now let us check the similarities of alternate host and collateral host.
-Alternate host and collateral hosts are the two hosts (not the principal host) on which a parasite can survive.
-Both types of host help the parasite in all its offseasons.
-An effective way of controlling pathogens that cause diseases is in control of the alternative hosts.

So, the correct answer is, “ Additional plant on which the life cycle is completed.”

Note: -The collateral host is also called alternative host as it plays an alternative role when the main host is not available. It is required for a parasite during off-seasons.
-A host can be present as a secondary or intermediate supporter, that is which can help for completing its life cycle, while the primary host is the one which helps for the maturity of the parasite. It is a cooperative helping relationship between 2 plants or organisms.
-As most of the parasites are obligate, they may also die when the host dies, but most probably a parasite never kills its host.