Answer:
radiometric dating methods
Explanation:
The oldest rock layer will be at the very bottom, and as time goes on, more layers will form making the top layer the youngest layer and the bottom layer the oldest. This method can determine the amount of radioactive decay of certain elements which can help them make a geologic time scale.
Answer: Option D.
Genotype by environment interaction.
Explanation:
Genotype by environment interaction refer to a situation where two different genotypes react differently in an environment. Light skinned humans are at greater risk of skin cancer because they lack melanin which the dark people have and this melanin protect the skin from sun.
All the choices are correct. Differences in the norm of reaction I.e they react different way.
Epistasis is when the effect of a gene suppress the other.
Pleiotrophy is when a gene influence another genes phenotipically. These are all genotype enviromr interaction.
Answer:
6. The number of protons of the atoms
7.The atomic number is equal to the number of protons and in a neutral atom the number of electrons
8. The atomic mass of elements equals number of protons plus number of neutrons
9. Protons and neutrons
10. Electrons
11. 8+9=17
12. 20+21=41
13. 10
Explanation: