Over a long period of time, helpful variations in a species replace the unfavorable ones. This change can lead to.

The different forms of a gene for a given trait are called .

Need will give 100 ! in no less than one hundred fifty words, explain why it is important for engineers to sketch designs and use them to clarify their designs to other people, giving at least three reasons.

Rick is on a bicycle trip. every 4 days he bikes 230 km. if rick keeps this same pace for 16 days, how many kilometers will he bike?