The geologist time scale was formed when scientists studied rock layers and index fossils worldwide. With this information, they placed Earth's rocks in order by relative age. Later, radioactive dating helped determine the exact age of the divisons in the geologic time scale.
This scale is organized by the 4.6 billion years of earth's history into sections based on important changes seen in the geologic record. The largest intervals are called eons, with each eon containing many millions of years.
In precambarian time the processes that affect Earth's surface have lessened the erosion on the surface. Earth was being hit by meteorites every second. Now there is water erosion and there wasn't back then. The surface changes have lessened over time.
Complete question:
Molecule 1 has the nitrogenous base sequence TCA AGT. Which set of bases in Molecule 2 can bond to that sequence in a complementary way?
a. UCAAGU
B. AGTACA
C. AGUUCA
D. UCAATA
Answer:
C. AGUUCA
Explanation:
DNA template strand and the corresponding RNA have complementary sequences. Adenine in the DNA template strand pairs with "uracil" base of RNA while cytosine pairs with its "guanine" base. Similarly, thymine base in DNA template strand pairs with "adenine" base in the RNA. This occurs since RNA does not have a thymine base. RNA has uracil base instead. Therefore, the molecule 1 with sequence TCA AGT would bind to the molecule 2 with the " AGU UCA" sequence.
Molecule 1: DNA template: TCA AGT
Molecule 2: mRNA: AGUUCA
