Tjio and Levan's contribution is very significant because they

In sickle cell anaemia$-$

Select the group of $CORRECT$ statements.
$I$. If phenotype of offsprings shows only the dominant trait then the parent plants are heterozygous.
$II$. $A$ true breeding line shows stable trait inheritance and expression for several generations.
$III$. In mendelian experiment material,contrasting characters can be easily recognized.
$IV$. When a single gene controls two (or more) different traits,it is called polygene.
$V$. When interactions occurs between the alleles of different genes present on the same or different chromosome it is called intragenic interaction.

When two genetic loci produce identical phenotypes in both $cis$ and $trans$ configurations,they are considered to be:

Which of the following is a dominant trait?

Which of the following is an example of codominance?