Question

In this week’s lab you will look for examples of phenotypic variation within and between species of plants, using both your unassisted eye and a microscope. But what sorts of phenotypeswill you not be able to observe in lab, and might they be variable, too? In your answer, detail two other kinds of unobservable (with our methods) phenotype that might vary within and between species and give a concrete example of each.

Answer 1

The expressed form of trait is called phenotype. Most of the traits can be observed either in lab or by watching. Examples: height -tall or short, shape of a seed- wrinkled or round, colour of flowers- violet or white etc.
The above types of traits are called observable forms of phenotypic traits, since they can be easily observed.

There are certain traits, which cannot be observed that easily. These are called unobservable phenotypic variations of cryptic variations.
Examples: 1.Antennapedia in Drosophila melanogaster flies.
It is a mutation that transforms the antennae into legs. When this mutation is placed in a dozen different wild-type genetic backgrounds, each strain will show a different phenotype, ranging from almost perfect antennae to almost perfect legs where the antennae should be. This is cryptic genetic variation modifying the mutant phenotype, even though it is unobservable in normal flies.
a human example, type 2 diabetes.
the prevalence of type2 diabetes is increasing dramatically worldwide along with the obesity epidemic. This is a highly heritable disease, but largely due to exposure of cryptic genetic variation by modern culture and lifestyle.