The question is incomplete as it does not have the options-
a. superfluous organ
b. extra appendage
c. vestigial structure
d. living fossil
e. chromosomal aberration.
Answer:
The correct answer will be option-vestigial structure
Explanation:
Vestigial structure are the structures which do not play any role in the organisms but still are inherited from the ancestors to maintain the fitness of the organisms.
Vestigial organs are found in many organisms including humans in which the presence of vermiform appendix do not play any role but it used to play roles in the ancestors of humans as they carried the cellulose-degrading bacteria.
Thus, a vestigial structure is the correct answer.
<h2>Gelatin </h2>
Explanation:
Gelatin is a differential medium which tests the ability of an organism to produce an exoenzyme, called gelatinase (this enzyme hydrolyzes gelatin)
When gelatin is at a temperature below 32°C (or within a few degrees thereof), it is a semisolid material and at temperatures above 32°C, it is a viscous liquid
When gelatin is broken down, it can no longer solidify and if an organism can break down gelatin, the areas where the organism has grown will remain liquid even if the gelatin is refrigerated
No the conclusion by student is not right because the tube must be runny after incubation followed by refrigeration to be considered gelatinase positive
