Abiochemist isolates, purifies, and combines in a test tube a variety of molecules needed for dna replication. when she adds some dna to the mixture, replication occurs, but each dna molecule consists of a normal strand paired with numerous segments of dna a few hundred nucleotides long. what has she probably left out of the mixture? a. dna ligase
b. nucleotides
c. dna polymerase iii
d. okazaki fragments

a. DNA ligase

Explanation:

DNA ligase is the enzyme of DNA replication that joins DNA segments together by catalyzing the formation of new phosphodiester bonds. These reactions use the energy of ATP molecules to form the bonds. The function of the DNA ligase enzyme is to join the Okazaki fragments together which in turn are formed during replication of the lagging strand. In the absence of DNA ligase, the Okazaki fragments cannot be joined together.

According to the given information, the process of DNA replication obtained shorts DNA segments of a few hundred nucleotides. This means that the reaction mixture lacked the DNA ligase enzyme and the DNA segments could not be joined together.

for the points

as the gila monster consumes the eggs or young of the desert cottontail and gambel's quail, thus its main food supply is only accessible for a restricted time duration every year. however, for this, the gila monsters exhibit three adaptations, which elevate their survival rate in the desert condition.  

first, is that they possess huge bodies, and can consume greater concentrations of food during a small period. secondly, they require to feed infrequently as they can accumulate fat in their tails. ultimately, their rate of metabolism is very low, so that they can burn their reservoirs of fat gradually.