What is the correct order for the application of Koch's postulates? a. Inoculate suspect agent into test subject and observe that subject develops disease of interest b. Isolate and culture suspect agent in the laboratoryc. Find suspect agent in every case of disease of interest but not in healthy hosts d. Recover and isolate suspect agent from the test subject

C. Find suspect agent in every case of disease of interest but not in healthy hosts

B. Isolate and culture suspect agent in the laboratory

A. Inoculate suspect agent into test subject and observe that subject develops disease of interest

D. Recover and isolate suspect agent from the test subject

Explanation:

Robert Koch, who was a German microbiologist, formulated an four postulates to show the relationship between a microorganism-causing disease and the disease.

The postulates, which were published by Robert Koch in 1890 are as follows:

1. The microbe (causative agent) must be found in diseased organisms but not in healthy ones.

2. The microbe must be isolated from the diseased organism and cultured i.e. grown

3. The cultured microbe, when inoculated into an healthy organism, must cause the same disease in that organism.

4. The microbe (causative agent) must be isolated again from the inoculated organism and be found to be identical to the previous microbe isolated from the diseased organisms.

Based on this four postulates, the correct order for the application of Koch's postulates will be:

C. Find suspect agent in every case of disease of interest but not in healthy hosts

B. Isolate and culture suspect agent in the laboratory

A. Inoculate suspect agent into test subject and observe that subject develops disease of interest

D. Recover and isolate suspect agent from the test subject

The genotypes of the parents are AArr and aaRr

Since, half the offspring trees produce big red apples and half produce big yellow apples we can conclude:

That all of the offspring inherited dominant trait for the size of apple (all of them are big) so, AA from one parent and aa from another can combine and form all heterozygous genotypes Aa. On the other hand, trait for the apple color is expressed 50-50-% (rr and Rr form Rr Rr rr rr genotypes).