Answer:
Both fish and bird embryos exhibit gill slits and a tail.
Explanation:
According to embryology, all vertebrates exhibit similar traits and structures at their embryonic stage. It becomes very difficult to differentiate between the embryos of a fish, and that of a bird, or embryo of a fish, and a human. These traits, however, disappear, as the case may be, as the embryo develops into an adult. For example, in the case of the embryo of a fish, and a bird, both shows gills slits at their respective embryonic stage. However, the gill slits in fish develop into gills, whereas in the case of birds, it disappears as the embryo develops into an adult.
The older the Earth's crust, the denser it is.
It is only active at a pH of around 2 because that is around the same pH as the gastric juices in the stomach which is where pepsin is used to break down proteins.
Answer:
Option C
Explanation:
All of the following options are correct except option C. in the Meselson Stahl experiment, after the first round of replication, the DNA molecules made consisted mainly of one parental strand and one new strand each which is the DNA molecules of intermediate density (H-L). Then future replications will produce more of the low density L-L density. This form of replication is thus termed to be the semi conservative form of replication
