I’m not sure but I think the answer is B or D
False.
Any time a scientific theory is challenged, it means it's not a good
theory. And this statement is not valid. In theoretical models, they are
revisited when there are further studies and discoveries found in a certain
area where they can be remodeled and reintegrated instead of disregarding its
credibility. Models, theories and paradigms are not challenged but rather
encouraged, they are supported in many studies since these theories and models
were created in order for us to understand a certain phenomenon but it would
likely help the scientific society to be updated in the new forms or spheres of
improvement rather than discouragement.
The correct options are as follows:
1. D.
Natural selection refers to the process by which living organisms that are more adapted to their environments usually survive and produce offspring that are like them. In the case of giraffes, the giraffes with the longest necks were able to survive in their environment and they reproduce offspring that are like them.
2. D
In the scientific world, scientists have open minds and they welcome all new ideas. These new ideas have to be tested to ensure that they are correct and superior to the facts that are already known. When a new hypothesis is put forward by a scientist, many scientists all over the world will test the hypothesis is order t confirm if it correct. If the hypothesis is found to be correct it will be accepted by all scientists.
3. A.
DNA test is a laboratory analysis that can be used to assess the level of relationship between living organisms. Related living organisms usually have some similar genes in their DNA, the level of closeness of these organisms will determine the quantity of similar genes that will be found in their DNA. Unrelated organisms on the other hand will have little or no similar genes in their DNA.
4. C.
The genetic code is the same across species, this fact points to the possibility that all living organisms originated from common ancestors. This support the evolution theory which stated that all living organisms descended from a common ancestor.
5. B.
Antibiotic drugs are usually effective against bacteria and other microbes, but the microbes can evolve and develop resistance to these drugs. Microbes are considered to have evolved when drugs that are used to inactivate them before no longer have any effect on them, thus they can easily survive in the presence of the drugs.
6. B.
If a particular specie of animal is able to avoid predators, it will increase in number more that those that are prey on by predators. The kings snakes were probably able to avoid predators, that is why, they were able to survive, reproduce offspring and increase in population in that particular ecosystem.
Answer:
The leading strand is copied in the 5' to 3' direction and the lagging strand is copied in the 3 to 5 direction.
Explanation:
1. The original DNA molecule remains intact, although it acts as a template for the formation of a copy that contains two new antiparallel strands. - this is false.
DNA replication is said to be "semi conservative". This is because in making a new DNA molecule, one of the strands is from the original DNA molecule and one is new. This is true for each new molecule produced One DNA molecule makes 2 new molecules, each containing one of the original strands
2. The leading strand is copied in the 5' to 3' direction and the lagging strand is copied in the 3 to 5 direction. This is true. The synthesis of each strand occurs through a distinct mechanism. The leading strand is synthesised 5'-3' (towards the replication fork), and the lagging strand is synthesised from 3'-5', away from the replication fork. T
he leading strand is synthesised continuously using an RNA primer to begin the process. The lagging strand is synthesised discontinuously, with several short primer sequences permitting the synthesis of short fragments (Okazaki fragments) that are later joined by DNA ligase. <em>NB: this is easy to remember if you consider that </em><em>3 lags behind 5</em>
3. Both strands are copied to form Okazaki fragments, which are later annealed by DNA Ligase. This is false. Only the lagging strand replicates to form Okazaki fragments
4. The replication process proceeds on both strands in the same direction, which requires that RNA primers bind to the lagging strand. This is false. The strands are synthesised in different directions
