Answer:
DNA ligase
Explanation:
DNA replication is an enzyme mediated, 3-step process during which the DNA molecule produces a copy of itself. The 3 steps involved are as follows;
- initiation
- elongation
- termination
<em>Initiation </em>involves the unwinding of the double helix structure of the DNA using DNA helicase enzyme
<em>Elongation</em> involves binding of RNA primer to the DNA strands and addition of bases to the primer<em> </em>to elongate the new chains. Bases are added to the leading strand continuously while the lagging strand is replicated in short segments (okazaki segments).
<em>Termination</em> involves the unbinding of RNA primer and substitution of its bases by DNA bases. The Okazaki fragments are then joined together using the DNA ligase enzyme.
<em>The short, numerous segments of DNA observed in the mixture is the Okazaki fragments of the lagging strand. This is due to the absence of the enzyme involved in the joining of these fragments.</em>
Hence, the answer is DNA ligase.
During interphase DNA is copied. So if there was no interphase, the new cells wouldn't have enough DNA.
Answer: B - People with two copies of the mutated gene have sickle-cell anemia. People with one copy of the mutated gene have both healthy and misshapen red blood cells and are carriers of the disease.
Explanation:
Co-dominance is when both the alleles of a gene in a heterozygote show. In the case of sickle cell anemia (since it is a co-dominant trait) even if the person only has one sickle cell allele, symptoms of sickle cell will still show up in that person. That's why the person in this example has both misshapen and healthy red blood cells.
The worm feeds via a "pumping" action in which it first uptakes the fluid surrounding it. Then, it expels the fluid while trapping any bacteria within it. The bacteria are then digested for energy and nutrients.
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1 = Birds, 2 = Mammals, 3 = Amphibians.
I took the test
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