Scientists have reportedly isolated short fragments of dna from fossilized dinosaur bones hundreds of millions of years old. the technique used to isolate this dna is the polymerase chain reaction, which is capable of amplifying very small amounts of dna a million‑fold. critics have claimed that the dna isolated from dinosaur bones is not purely of ancient origin but instead has been contaminated by dna from present‑day organisms, such as bacteria, mold, or humans. what precautions, analyses, and control experiments could be carried out to ensure that dna recovered from fossils is truly of ancient origin

Which way do the nitrogenous bases in dna pair up? a. a and g; t and c b. a and c; t and g c. a and t; g and c d. a and a; t and t; g and g; c and c

Hurry i need your (100 points) 1) what are the responsibilities of the region of the brain highlighted below? (picture located below) the highlighted portion is at the rear base of the brain, behind the brain stem. regulating homeostasis, hunger and eating, thirst and drinking, and many other functions of basic survival. coordinating movement and balance by using information from sensory nerves, including hand-eye coordination. controlling voluntary body movements, processing information from sense organs, thoughts, and learning abilities. regulating important involuntary bodily functions such as blood pressure, heart rate, breathing, and swallowing. 2)which of the following systems or structures is correctly paired with its function? neurons - brain cells that control thoughts, calculations, and memory cerebral cortex - portion of the brain that controls involuntary body movement peripheral nervous system - carries impulses to and from the central nervous system central nervous system - carries information from the nerves to the muscles and glands

Which of the following is a good definition for the word adaptation? question 1 options: a trait that an organism survive and reproduce in its environment. a change in an organism's environment. the way in which animals obtain food. a temperature change that can cause the extinction of plants and animals.