If I remember them correctly, the organisms are a fish, a reptile a bird and a human during embryonic development. B & D are the correct answers.
Answer:
If your cartilage, muscles, or tendons put too much pressure on a nerve, it might not be able to work right. This can cause numbness. An injury or overuse can cause a pinched nerve. Sometimes it's due to health problems like arthritis, a narrowing of the spaces between the bones in your spine, or a tumor on the spine.
hope this answer helps you.....
Answer:
Complementary base pairing is the phenomenon where in DNA guanine always hydrogen bonds to cytosine and adenine always binds to thymine. The bond between guanine and cytosine shares three hydrogen bonds compared to the A-T bond which always shares two hydrogen bonds.
The right answer to this question is option C. the traits acted upon natural selection were genes.
At the time Charles Darwin developed the evolution theory, there wasn't a single study about genes in all science scenery, that could be explained by the lack of technology to study them and even to know they existed in the first place.
So, his theory was basically talking about adaptation, if an organism can't survive a specific environment, he'll probably die until another generation comes in and this one can survive in this environment, passing their genes to the next ones. The lack of information was the knowledge about the genes we have today, that's why most scientists take only the new Darwin theory, that includes the study of genes.