Answer the following question given this paragraph: Within seconds of birth, the umbilical cord is cut. Without this connection to the placenta, the baby can't exchange gases, so carbon dioxide quickly builds up in the baby's blood. This stimulates the baby's brain to trigger breathing, and the newborn takes her first breath. Q: What structure connects the fetus to the placenta, allowing the exchange of gases? Choices: - sediment cord - skin cord - belly button - umbilical cord A:
umbilical cord

Answer the following question given this paragraph: Comets carry materials in from the outer solar system. Comets may have brought water into the early Earth. Other substances could also have come from comets. Q: What is rusting an example of? Choices: - radiation change - Decomposition - contamination change - chemical change A:
chemical change

Answer the following question given this paragraph: Extensive properties vary according to the amount of matter present. Examples of extensive properties include mass, volume, and length. Q: What are mass, volume, and length an example of? Choices: - extensive compounds - dynamic properties - fantastic properties - extensive properties A:
extensive properties

Answer the following question given this paragraph: Watch this animation (http://openstaxcollege. org/l/p53_cancer) to learn more about the use of p53 in fighting cancer. Proto-oncogenes are positive cell-cycle regulators. When mutated, proto-oncogenes can become oncogenes and cause cancer. Overexpression of the oncogene can lead to uncontrolled cell growth. This is because oncogenes can alter transcriptional activity, stability, or protein translation of another gene that directly or indirectly controls cell growth. An example of an oncogene involved in cancer is a protein called myc. Myc is a transcription factor that is aberrantly activated in Burkett's Lymphoma, a cancer of the lymph system. Overexpression of myc transforms normal B cells into cancerous cells that continue to grow uncontrollably. High B-cell numbers can result in tumors that can interfere with normal bodily function. Patients with Burkett's lymphoma can develop tumors on their jaw or in their mouth that interfere with the ability to eat. Q: Proto-oncogenes are positive cell-cycle regulators but when mutated, they can become what? Choices: - microbes and cause cancer - bacteria and cause cancer - cultigens and cause cancer - oncogenes and cause cancer A:
oncogenes and cause cancer