Based on radiometric dating and the rock and fossil record, scientists have concluded that life has been present on earth a. for about 1 billion years. b. for about 50,000 years. c. for no more than 10 million years. d. for at least 3.5 billion years.

Many farmers prefer cattle without horns because it is safer for their herds. the allele for no horns (n) is dominant to the allele for the presence of horns (n). a farmer mates a male with horns to a heterozygous female without horns. what is the chance that the offspring will have horns?

Urgent. the table shows the relative blood flow through some organs in the human body that is, the percentage of blood that flows through a given organ, through which organ(s) does all the blood flow? explain the effect of exercise on blood flow to skeletal muscles.

Explain how organisms could be harmed by high levels of salt from roadways?