There is misspelled. It should be spelled their
Answer:
c. The ultimate source of new alleles is mutation, random changes in the nucleotide sequences of an organism's DNA
Explanation:
Mutations are changes in DNA sequence that can create genetic variation within the population. Mutations are important for evolution because of their ability to form a new genetic variant (allele) that can be spread to the offspring. If a new variant of a trait formed by a mutation is advantageous and helps the organism to survive and reproduce, it is going to be favourable by natural selection. That variation will more likely be passed to the next generation and remain over time.
Answer:
D
Explanation:
Comets are brightest near the sun.
Answer:
The correct answer is option D, Unconfined aquifers are found between two layers of impermeable soil or rock.
Explanation:
An unconfined aquifer is not confined by rock layer on both of its side. Usually the ground water level (GWL) is considered as the upper layer of unconfined aquifer. Also the rocky layer found on the other side of the unconfined aquifer is not impermeable as the major source of recharge of unconfined aquifer is the seepage of water through is permeable layer or through rain.