Answer:
is the process of breeding only organisms with desirable traits
Explanation:
Answer:
D. We know more about the Cenozoic era because this the most recent time period in the history of the Earth, and we have more information available to study.
Explanation:
The Cenozoic era is the era that is by far the best studied and known by the scientists. The main reason for this is that this era is the most recent one, and it is actually the era we live in. Because it is the most recent era, the Cenozoic is abundant with lot of evidence of what has happened in it. The fossil records are very rich as the fossils didn't had that much time to totally decompose. The rock layers are much younger, so they contain much more detailed evidence of the plant life, climate, changes in the environment. The oceanic crust is also in abundance, which is not the case with the other eras as the oceanic crust is constantly suducted.
When a biologist counts the number of zebras in a population each year and notices an increase in the zebra population, this would be an example "of <span>observation"</span>
It helps to give solid evidence of natural selection. The idea is that there are a number of finches in the Galapagos Islands. These birds vary slightly in appearance, in the function of their beaks and in size. Two species can eventually alter themselves because of the environmental conditions they live in. Some traits will be passed on or developed in one group and not in the other or vica versa. These finches are remarkable in that it did not take long for the changes to take place. It is probably one of the strongest reasons for believing in natural selection, because only those birds who could adapt to change could easily pass on these advantages to their offspring. The relatively short period of time to enact these changes is what makes the this example so attractive.
Answer:
a. positive; negative
Explanation:
Transcription is the process of forming an RNA molecule from a DNA template molecule. In this process, the strands of DNA separate and one serves as a template for RNA, while the other is inactive. At the end of the transcript, the tapes that have been split back together again.
The transcription process is divided into three steps: initiation, stretching and termination
During the stretching phase, transcription chain elongation occurs. In this phase the enzyme called RNA polymerase starts to move through the DNA molecule, unwinding its helix and producing an increasingly lengthened RNA molecule. The already transcribed DNA is rewound almost immediately, recomposing its double helix. This process is called the elongation phase.
During this process, it is believed that positive supercoils are generated ahead of the transcription bubble and and the negative supercoils behind it.
