Suppose unattached earlobes are a dominant trait. phil and maggie both have unattached earlobes but their daughter, celia, does not. if phil and maggie have a second child, what is the probability that he or she will have attached earlobes?
a. 1/4
b. 1/2
c. 3/4
d. 1/8
e. 1

The correct option is A. 1/4

Explanation:

Let's try to interpret the results by drawing a punnet square for the cross.

Let's consider E to be the dominant allele and e to be the recessive allele.

The cross can be shown as :

        E       e                                          

E      EE     Ee                                

e       Ee     ee          

The results from the punnet square prove that 1/4  of the offsprings will have a chance to have attached earlobes.              

step 1: initiation

initiation is the beginning of transcription. it occurs when the enzyme rna polymerase binds to a region of a gene called the promoter. this signals the dna to unwind so the enzyme can ‘‘read’’ the bases in one of the dna strands. the enzyme is now ready to make a strand of mrna with a complementary sequence of bases.

step 2: elongation

elongation is the addition of nucleotides to the mrna strand. rna polymerase reads the unwound dna strand and builds the mrna molecule, using complementary base pairs. there is a brief time during this process when the newly formed rna is bound to the unwound dna. during this process, an adenine (a) in the dna binds to an uracil (u) in the rna.

step 3: termination

termination is the ending of transcription, and occurs when rna polymerase crosses a stop (termination) sequence in the gene. the mrna strand is complete, and it detaches from dna.