I like to think of the DNA molecule strand as a ladder, rather than a spiral staircase. The siderail of the DNA ladder (The DNA "Backbone") consists of the Sugar and Phosphate molecules. The rungs of the ladder (the inner bases) consist of the pairs of Nitrogen Bases - Adenine, Guanine, Cytosine and Thymine.
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alisa202
Answer:
The correct statements are,:
B. Resistance to the anti-viral drug ganciclovir indicates that homologous recombination has occurred.
C. Homologous recombinants of the knockout alleles are desired since they will replace the wildtype allele
E. The embryonic stem cells carrying homologous recombinants of the knockout allele are placed back into a blastocyst and injected into a surrogate mother to produce mice carrying the knockout allele.
Explanation:
<u>wrong statements</u>
A. Illegitimate recombinants have the knockout allele randomly inserted and do not replace the wildtype alleles and may potentially insert into other genes and confound the analysis
D. Resistance to neomycin indicates insertion of the knockout allele but does not distinguish between homologous and non-homologous recombinants
A and D are wrong statement due to the fact that Cells that were transformed with a vector containing the neomycin gene and the herpes tk+ gene are grown in a solution that contains neomycin and Ganciclovir in order to distinguish the transformations that occured through homologous recombination. Any DNA insertion that occurred through random insersion( illegitimate recombinant) will die because the tests positive for both neomycin resistant gene and herpes tk+ gene whose gene product reacts with Ganciclovir to produce deadly toxins.
Answer:
half the number of chromosomes as the original cell
Explanation:
Answer:
20 amino acids.
Explanation:
Amino acids are the monomers that combine together to form a protein. Two main types of amino acids are non- essential amino acids and essential amino acids.
Thousands of different proteins can be made by the simple 20 amino acids present in the cell. The amino acids can combine in different ways to form all the proteins present in the body.
Thus, the correct answer is option (5).
