Answer:
B) Polymerases can only synthesize in the 5' to 3' direction
Explanation:
The leading strand's directionality is 3' to 5', so polymerase has no problem with replicating this one. But the lagging strand has the opposite directionality, so the polymerase must work in the opposite direction of the replication fork.In consequence, the replication process undergoes periodic breaks, and the enzymes have to stop and start again while helicase separates both strands, resulting in the polymerization of okazaki fragments.
Birds, insects, and many reptiles excrete nitrogenous waste in the form of uric acid, which saves water.
Nitrogenous waste in the body tend to form toxic ammonia, which must be excreted. Mammals such as human excrete urea, while birds, reptiles, and some terrestrial invertebrates produce uric acid as waste in the form of a white paste or power. The production of uric acid involves a complex metabolic pathway that is energetically costly in comparison to processing of other nitrogenous wastes such as urea or ammonia, it has the advantages of reducing water loss and, hence, reducing the need for water.
Answer:
a. the first methionine in eukaryotic translation contains a formyl group.
Explanation:
Protein synthesis begins when the initiator aminoacyl tRNA carrying the initiator amino acid joins the mRNA-small ribosomal subunit complex. Procaryotes and eucaryotes differ from each other in the identity of the first initiator amino acid. In both types of organisms, "AUG" serves as an initiation codon. However, procaryotes have formyl-methionine joined to the amino acid arm of the initiator tRNA while eucaryotic initiator tRNA carries methionine as the first amino acid to be added to the protein.
Carbon is an essential to all living forms on earth, whether they need carbon intake to help produce food or release carbon for breathing. All plants and animal life need carbon, without it would be impossible for life on earth.
