There are all sorts of ways to reconstruct the history of life on Earth. Pinning down when specific events occurred is often tricky, though. For this, biologists depend mainly on dating the rocks in which fossils are found, and by looking at the “molecular clocks” in the DNA of living organisms.
There are problems with each of these methods. The fossil record is like a movie with most of the frames cut out. Because it is so incomplete, it can be difficult to establish exactly when particular evolutionary changes happened.
Modern genetics allows scientists to measure how different species are from each other at a molecular level, and thus to estimate how much time has passed since a single lineage split into different species. Confounding factors rack up for species that are very distantly related, making the earlier dates more uncertain.
These difficulties mean that the dates in the timeline should be taken as approximate. As a general rule, they become more uncertain the further back along the geological timescale we look. Dates that are very uncertain are marked with a question mark.
Answer:
Option A (dark energy) is the right answer.
Explanation:
- A hypothetical supplier of power that creates a force that contradicts gravity, which is assumed to have been the catalyst of accelerated universe development.
- Hypothetically, dark energy counteracts the kinetic energy including its beginning of the globe, meaning that perhaps the multiverse does not have intrinsic curvature, although observational measurements presently indicate.
Some other three choices have no relation to the particular situation. Thus option A would be the right solution.
Answer:
Transcription
Explanation:
First comes Transcription, then comes Translation.
For example, DNA comes first, RNA comes second, and Protein comes third which makes proteins last. So, during the DNA process, Replication occurs. After that, DNA hops over to RNA using Transcription, and after that RNA hops over to Protein using Translation. So, we look left to right. Now, when I listed everything, Transcription came first and Translation came second. There is your answer.
Answer:
B? Hope this helps, sorry if it's wrong.
Explanation:
A generic embryonic cell is different from a differentiated cell because it has a specific structure to perform a certain function. During development, cells become increasingly different from one another so that they can be specialized for specific functions.
<h3>What are embryonic cells?</h3>
These stem cells come from embryos that are 3 to 5 days old. At this stage, an embryo is called a blastocyst and has about 150 cells. These are pluripotent (ploo-RIP-uh-tunt) stem cells, meaning they can divide into more stem cells or can become any type of cell in the body.
With this information, we can conclude that Cell differentiation is how generic embryonic cells become specialized cells. This occurs through a process called gene expression. Gene expression is the specific combination of genes that are turned on or off (expressed or repressed), and this is what dictates how a cell functions.
Learn more about embryonic cells in brainly.com/question/11980984
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