Answer is Middle Paleozoic era.
Paleozoic era was in 542 Ma - 245 Ma and it has 6 periods as Cambrian, Ordovician, Silurian, Devonian, Carboniferous and Permian.
360-280 Ma - forming of vascular plants with woody tissues, seeds and veins.
430 - 410 Ma - forming of jawed fishes and first amphibians.
420 Ma - forming of scorpions
360 Ma - forming of crustaceans.
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.
Answer:
D
Explanation:
Units of weight and volume won't be large enough to be meaningful. so liters and grams are too small. Find out the weight of a cubic meter of water and then estimate how many cubic meters there might be in a lake. Millions would probably be too small.
Miles are too big. Most lakes do not go to a depth of 1 mile, but you on on the right track. Distance is what you want.
Meters are the answer.
A codon is a sequence of three bases found on the messenger RNA (mRNA) molecule which is translated to produce an amino acid. Each amino acid is coded by one or more specific codons. If the codon is changed through a mutation, the amino acid produced may be different. However, in this case, the other codons that produce Leucine are:
UUA, UUG, CUU, CUC, CUA and CUG
So the code CUU could mutate to CUC, CUA or CUG and leucine would still be produced.
